Must have non-null value for 'Binding' problem

Must have non-null value for 'Binding' problem - c#

I have made a custom Control in WPF which is a star rating. When there are 5 stars, these should be golden.
<UserControl x:Class="Lama.Wpf.Controls.RatingControl"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:controls="clr-namespace:Lama.Wpf.Controls"
mc:Ignorable="d">
<Grid>
<Grid.Resources>
<ControlTemplate x:Key="RatingTemplate" TargetType="{x:Type ToggleButton}">
<Viewbox>
<Path Name="star" Fill="White" Opacity="0.2"
Data="F1 M 145.637,174.227L 127.619,110.39L 180.809,70.7577L 114.528,68.1664L 93.2725,5.33333L 70.3262,67.569L 4,68.3681L 56.0988,109.423L 36.3629,172.75L 91.508,135.888L 145.637,174.227 Z" />
</Viewbox>
<ControlTemplate.Triggers>
<MultiDataTrigger>
<MultiDataTrigger.Conditions>
<Condition Property="IsChecked" Value="True" />
<Condition
Binding="{Binding Rating, RelativeSource={RelativeSource FindAncestor, AncestorType=controls:RatingControl}}"
Value="5" />
</MultiDataTrigger.Conditions>
<MultiDataTrigger.Setters>
<Setter TargetName="star" Property="Fill" Value="Gold" />
<Setter TargetName="star" Property="Opacity" Value="1" />
</MultiDataTrigger.Setters>
</MultiDataTrigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Grid.Resources>
<Grid.ColumnDefinitions>
<ColumnDefinition />
<ColumnDefinition />
<ColumnDefinition />
<ColumnDefinition />
<ColumnDefinition />
</Grid.ColumnDefinitions>
<ToggleButton Grid.Column="0" Tag="1" Padding="2" Template="{StaticResource RatingTemplate}"
Click="ClickEventHandler" />
<ToggleButton Grid.Column="1" Tag="2" Padding="2" Template="{StaticResource RatingTemplate}"
Click="ClickEventHandler" />
<ToggleButton Grid.Column="2" Tag="3" Padding="2" Template="{StaticResource RatingTemplate}"
Click="ClickEventHandler" />
<ToggleButton Grid.Column="3" Tag="4" Padding="2" Template="{StaticResource RatingTemplate}"
Click="ClickEventHandler" />
<ToggleButton Grid.Column="4" Tag="5" Padding="2" Template="{StaticResource RatingTemplate}"
Click="ClickEventHandler" />
</Grid>
</UserControl>
public partial class RatingControl
{
private const int Max = 5;
public static readonly DependencyProperty RatingProperty = DependencyProperty.Register(nameof(Rating),
typeof(int),
typeof(RatingControl),
new FrameworkPropertyMetadata(0, FrameworkPropertyMetadataOptions.BindsTwoWayByDefault,
RatingChanged));
public int Rating
{
get => (int)GetValue(RatingProperty);
set
{
if (value < 0)
{
SetValue(RatingProperty, 0);
}
else if (value > Max)
{
SetValue(RatingProperty, Max);
}
else
{
SetValue(RatingProperty, value);
}
}
}
public RatingControl()
{
InitializeComponent();
}
private static void RatingChanged(DependencyObject sender, DependencyPropertyChangedEventArgs e)
{
var item = sender as RatingControl;
var newVal = (int)e.NewValue;
var children = ((Grid)(item.Content)).Children;
ToggleButton button;
for (var i = 0; i < newVal; i++)
{
button = children[i] as ToggleButton;
if (button != null)
button.IsChecked = true;
}
for (var i = newVal; i < children.Count; i++)
{
button = children[i] as ToggleButton;
if (button != null)
button.IsChecked = false;
}
}
private void ClickEventHandler(object sender, RoutedEventArgs args)
{
var button = sender as ToggleButton;
if (button == null)
{
return;
}
var newValue = int.Parse(button.Tag.ToString());
Rating = newValue;
}
}
If I run this, I get this exception:
InvalidOperationException: Must have non-null value for 'Binding'.
Do I bind something wrong inside my condition? Because if I remove the Rating-Binding, it works, but I don't see my mistake here.

There are multiple issues in your Condition bindings:
The first binding in the MultiDataTrigger uses a Condition that sets Property, which is wrong.
For a MultiDataTrigger, each condition in the collection must set both the Binding and Value properties. For more information, see Binding.
Set the Binding property using a RelativeSource binding to Self instead.
<Condition Binding="{Binding IsChecked, RelativeSource={RelativeSource Self}}" Value="True"/>
The second binding to Rating is faulty, since it would only ever set any star to be golden and opaque if the rating is exactly five stars. So no stars are selected for any other rating.
In order resolve these issues, you can use a simple Trigger on the IsChecked property.
<ControlTemplate.Triggers>
<Trigger Property="IsChecked" Value="True">
<Setter TargetName="star" Property="Fill" Value="Gold" />
<Setter TargetName="star" Property="Opacity" Value="1" />
</Trigger>
</ControlTemplate.Triggers>
If it is really your requirement to only make the stars golden and opaque if the rating is exactly 5, then you could correct the MultiDataTrigger as stated above:
<ControlTemplate.Triggers>
<MultiDataTrigger>
<MultiDataTrigger.Conditions>
<Condition Binding="{Binding IsChecked, RelativeSource={RelativeSource Self}}" Value="True"/>
<Condition Binding="{Binding Rating, RelativeSource={RelativeSource FindAncestor, AncestorType=controls:RatingControl}}" Value="5"/>
</MultiDataTrigger.Conditions>
<MultiDataTrigger.Setters>
<Setter TargetName="star" Property="Fill" Value="Gold" />
<Setter TargetName="star" Property="Opacity" Value="1" />
</MultiDataTrigger.Setters>
</MultiDataTrigger>
</ControlTemplate.Triggers>
Another note on value coercion. As #Clemens stated in the comments, setting a property in XAML e.g. like below will bypass your setter and
call SetValue directly. Your setter should only call SetValue as the behavior will differ otherwise when setting properties in XAML or through the property.
<local:RatingControl Rating="{Binding SomeProperty}"/>
Instead of the checks in the setter, you can specify a value coercion callback in the dependency property declaration.
public static readonly DependencyProperty RatingProperty = DependencyProperty.Register(
nameof(Rating), typeof(int), typeof(RatingControl), new FrameworkPropertyMetadata(
0, FrameworkPropertyMetadataOptions.BindsTwoWayByDefault, RatingChanged, CoerceRating));
Then create a CoerceRating method that contains your checks and returns the corresponding values.
private static object CoerceRating(DependencyObject d, object baseValue)
{
var value = (int)baseValue;
if (value < 0)
{
return 0;
}
if (value > Max)
{
return Max;
}
return value;
}
Finally, remove all checks from the setter of Rating.
public int Rating
{
get => (int)GetValue(RatingProperty);
set => SetValue(RatingProperty, value);
}
The value coercion callback will automatically be called, when the property is set through SetValue and therefore ensure that the Rating value is within the valid interval.

Related

Change button appearance/icon

I want to change the icon on my button. Here is the xaml of my button:
<Button Name="InitPurgeBtn" Click="InitPurgeClick">
<Rectangle Width="35" Height="45" Margin="0,0,0,0">
<Rectangle.Fill>
<VisualBrush Stretch="Fill" Visual="{StaticResource InitIcon}" />
</Rectangle.Fill>
</Rectangle>
</Button>
The probleme is I don't know how to acces the Visual property of the Rectangle of my button in my controller to change "InitIcon" by "PurgeIcon"
All my icon are implement in xaml:
<Viewbox x:Key="ExtinctionIcon" Stretch="Uniform" x:Shared="False">
<Canvas Width="76" Height="76" Clip="F1 M 0,0L 76,0L 76,76L 0,76L 0,0">
<Path Width="40" Height="40" Stretch="Fill" Fill="{Binding Foreground,
RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=Button}}"
Data="M15,24H17V22H15M16.56,{...}24H13V22H11M7,24H9V22H7V24Z"/>
</Canvas>
</Viewbox>
Edit :
I change my button and he is like this now :
<Button Name="InitBtn" Style="{StaticResource RoundButton}" Width="70" Height="70"
Click="InitPurgeClick" Content="{StaticResource InitIcon}">
</Button>
I want to change the icon in my code so I try to set Content property like this :
InitBtn.Content = "{StaticResource ExtinctionIcon}";
But this way just replace my icon with the string "StaticResource.."

Updated to reflect new information
You updated your question with some new information that changes things a lot.
Since you are trying to update Button.Content in code, you won't be able to use the MarkupExtension. MarkupExtensions (the stuff inside { } in the XAML) are only evaluated when the view is initially created. After that, they behave just like regular strings, so trying to set one in code won't work.
To set the value in code, you will need to manually do what the MarkupExtension is doing; find the resource by name, and set the value directly. You can do this with the following code (assuming a reference to InitPurgeBtn).
InitPurgeBtn.Content = InitPurgeBtn.FindResource("ExtinctionIcon");
Previous Answer
You should be able to add your icon to the Content of the Button directly, as it seems to be defined as a resource somewhere (because of the x:Key attribute). Your code doesn't show where exactly that is though, so I can't grantee this will work without some modification.
<Button Name="InitPurgeBtn"
Width="100"
Height="40"
Content="{StaticResource ExtinctionIcon}" />
In order for that to work the ExtinctionIcon resource will have to be defined someplace accessible to the button, meaning either in an ancestor of the button, or in App.xaml.
The fact that the resource is defined with x:Shared="false" seems to indicate that it was designed to be used in exactly this way, as that is required for visual elements that can possibly be hosted in multiple places simultaneously.
Alternatively, you could just copy and embed the icon directly in to the button.
<Button Name="InitPurgeBtn"
Click="InitPurgeClick">
<Viewbox Stretch="Uniform">
<Canvas Width="76"
Height="76"
Clip="F1 M 0,0L 76,0L 76,76L 0,76L 0,0">
<Path Width="40"
Height="40"
Stretch="Fill"
Fill="{Binding Foreground,
RelativeSource={RelativeSource
Mode=FindAncestor,
AncestorType=Button}}"
Data="M15,24H17V22H15M16.56,{...}24H13V22H11M7,24H9V22H7V24Z"/>
</Canvas>
</Viewbox>
</Button>

You may use Content property.
<Button Name="InitPurgeBtn" Width="100" Height="40">
<Button.Content>
<Image Source=".\Icon.PNG"/>
</Button.Content>
</Button>

If you just want a single (xaml) icon, you can bind the content property of your button to your icon resource.
The control below gives an enhanced display - a xaml icon plus a text caption, including two colours for the icon and support for disabled state.
MyXamlIconHost.cs
public enum CaptionPosition { None, ToLeftOfIcon, AboveIcon, ToRightOfIcon, BelowIcon }
public enum IconSize { Small, Medium, Large, XLarge, XxLarge }
public class myXamlIconHost : Control
{
private static readonly Brush DefaultForeground = new SolidColorBrush(Color.FromRgb(32,32,32));
private static readonly Brush DefaultHighlight = Brushes.DarkOrange;
private static readonly Brush DefaultDisabledForeground = new SolidColorBrush(Color.FromRgb(192, 192, 192));
private static readonly Brush DefaultDisabledHighlight = new SolidColorBrush(Color.FromRgb(128, 128, 128));
static myXamlIconHost()
{
DefaultStyleKeyProperty.OverrideMetadata(typeof(myXamlIconHost), new FrameworkPropertyMetadata(typeof(myXamlIconHost)));
}
public FrameworkElement XamlIcon
{
get { return (FrameworkElement)GetValue(XamlIconProperty); }
set { SetValue(XamlIconProperty, value); }
}
public static readonly DependencyProperty XamlIconProperty =
DependencyProperty.Register("XamlIcon", typeof(FrameworkElement), typeof(myXamlIconHost), new PropertyMetadata(null));
public IconSize IconSize
{
get { return (IconSize)GetValue(IconSizeProperty); }
set { SetValue(IconSizeProperty, value); }
}
public static readonly DependencyProperty IconSizeProperty =
DependencyProperty.Register("IconSize", typeof(IconSize), typeof(myXamlIconHost), new PropertyMetadata(IconSize.Medium));
public string Caption
{
get { return (string)GetValue(CaptionProperty); }
set { SetValue(CaptionProperty, value); }
}
public static readonly DependencyProperty CaptionProperty =
DependencyProperty.Register("Caption", typeof(string), typeof(myXamlIconHost), new PropertyMetadata(null));
public CaptionPosition CaptionPosition
{
get { return (CaptionPosition)GetValue(CaptionPositionProperty); }
set { SetValue(CaptionPositionProperty, value); }
}
public static readonly DependencyProperty CaptionPositionProperty =
DependencyProperty.Register("CaptionPosition", typeof(CaptionPosition), typeof(myXamlIconHost), new PropertyMetadata(CaptionPosition.ToRightOfIcon));
public Brush StandardForeground
{
get { return (Brush)GetValue(StandardForegroundProperty); }
set { SetValue(StandardForegroundProperty, value); }
}
public static readonly DependencyProperty StandardForegroundProperty =
DependencyProperty.Register("StandardForeground", typeof(Brush), typeof(myXamlIconHost), new PropertyMetadata(DefaultForeground));
public Brush StandardHighlight
{
get { return (Brush)GetValue(StandardHighlightProperty); }
set { SetValue(StandardHighlightProperty, value); }
}
public static readonly DependencyProperty StandardHighlightProperty =
DependencyProperty.Register("StandardHighlight", typeof(Brush), typeof(myXamlIconHost), new PropertyMetadata(DefaultHighlight));
public Brush DisabledForeground
{
get { return (Brush)GetValue(DisabledForegroundProperty); }
set { SetValue(DisabledForegroundProperty, value); }
}
public static readonly DependencyProperty DisabledForegroundProperty =
DependencyProperty.Register("DisabledForeground", typeof(Brush), typeof(myXamlIconHost), new PropertyMetadata(DefaultDisabledForeground));
public Brush DisabledHighlight
{
get { return (Brush)GetValue(DisabledHighlightProperty); }
set { SetValue(DisabledHighlightProperty, value); }
}
public static readonly DependencyProperty DisabledHighlightProperty =
DependencyProperty.Register("DisabledHighlight", typeof(Brush), typeof(myXamlIconHost), new PropertyMetadata(DefaultDisabledHighlight));
}
// ==============================================================================================================================================
public class myXamlIconSizeConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
const int defaultSize = 24;
if (!(value is IconSize))
return defaultSize;
var iconSizeValue = (IconSize)value;
switch (iconSizeValue)
{
case IconSize.Small:
return defaultSize * 2 / 3;
case IconSize.Large:
return defaultSize * 3 / 2;
case IconSize.XLarge:
return defaultSize * 2;
case IconSize.XxLarge:
return defaultSize * 5 / 2;
default:
return defaultSize;
}
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
{
return null;
}
}
MyXamlIconHost.xaml
<Style TargetType="{x:Type ctrl:myXamlIconHost}">
<Setter Property="Focusable" Value="False" />
<Setter Property="HorizontalAlignment" Value="Center" />
<Setter Property="Padding" Value="0" />
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type ctrl:myXamlIconHost}">
<Grid Margin="{TemplateBinding Padding}">
<Grid.Resources>
<ctrl:myXamlIconSizeConverter x:Key="IconSizeConverter" />
</Grid.Resources>
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto" />
<ColumnDefinition Width="Auto" />
<ColumnDefinition Width="Auto" />
</Grid.ColumnDefinitions>
<TextBlock x:Name="PART_CaptionTextBlock"
Grid.Row="1"
Grid.Column="0"
Margin="8,0,8,0"
HorizontalAlignment="Center"
VerticalAlignment="Center"
Foreground="{TemplateBinding StandardForeground}"
Text="{TemplateBinding Caption}" />
<!-- Set DataContext to "self" so that the Xaml Icon item can bind to the Foreground and BorderBrush properties -->
<ContentControl x:Name="PART_IconPresenter"
Grid.Row="1"
Grid.Column="1"
Width="{TemplateBinding IconSize,
Converter={StaticResource IconSizeConverter}}"
Height="{TemplateBinding IconSize,
Converter={StaticResource IconSizeConverter}}"
HorizontalAlignment="Center"
VerticalAlignment="Center"
BorderBrush="{TemplateBinding StandardHighlight}"
Content="{TemplateBinding XamlIcon}"
DataContext="{Binding RelativeSource={RelativeSource Self}}"
Focusable="False"
Foreground="{TemplateBinding StandardForeground}" />
</Grid>
<ControlTemplate.Triggers>
<Trigger Property="IsEnabled" Value="False">
<Setter TargetName="PART_CaptionTextBlock" Property="Foreground" Value="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=DisabledForeground}" />
<Setter TargetName="PART_IconPresenter" Property="BorderBrush" Value="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=DisabledHighlight}" />
<Setter TargetName="PART_IconPresenter" Property="Foreground" Value="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=DisabledForeground}" />
</Trigger>
<Trigger Property="CaptionPosition" Value="None">
<Setter TargetName="PART_CaptionTextBlock" Property="Visibility" Value="Collapsed" />
</Trigger>
<Trigger Property="CaptionPosition" Value="ToLeftOfIcon">
<Setter TargetName="PART_CaptionTextBlock" Property="Grid.Column" Value="0" />
<Setter TargetName="PART_CaptionTextBlock" Property="Grid.Row" Value="1" />
<Setter TargetName="PART_CaptionTextBlock" Property="Margin" Value="8,0,8,0" />
</Trigger>
<Trigger Property="CaptionPosition" Value="ToRightOfIcon">
<Setter TargetName="PART_CaptionTextBlock" Property="Grid.Column" Value="2" />
<Setter TargetName="PART_CaptionTextBlock" Property="Grid.Row" Value="1" />
<Setter TargetName="PART_CaptionTextBlock" Property="Margin" Value="8,0,8,0" />
</Trigger>
<Trigger Property="CaptionPosition" Value="AboveIcon">
<Setter TargetName="PART_CaptionTextBlock" Property="Grid.Column" Value="1" />
<Setter TargetName="PART_CaptionTextBlock" Property="Grid.Row" Value="0" />
<Setter TargetName="PART_CaptionTextBlock" Property="Margin" Value="8,0,8,4" />
</Trigger>
<Trigger Property="CaptionPosition" Value="BelowIcon">
<Setter TargetName="PART_CaptionTextBlock" Property="Grid.Column" Value="1" />
<Setter TargetName="PART_CaptionTextBlock" Property="Grid.Row" Value="2" />
<Setter TargetName="PART_CaptionTextBlock" Property="Margin" Value="8,4,8,0" />
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
<Setter Property="VerticalAlignment" Value="Center" />
</Style>
Example Usage
<Window ... >
<Window.Resources>
<Grid x:Key="TestIcon" x:Shared="False" Background="Transparent">
<Path Stretch="Fill" Data=" M 0,0 M 100,100 M 0,0 L 0,100 L 100,100 L 100,60 L 90,60 L 90,90 L 10,90 L 10,10 L 90,10 L 90,40 L 100,40 L 100,0 z" Fill="{ Binding Foreground, FallbackValue=Cyan}"/>
<Path Stretch="Fill" Data=" M 0,0 M 100,100 M 70,45 L 100,45 L 100,55 L 70,55 z" Fill="{ Binding BorderBrush, FallbackValue=Magenta}"/>
</Grid>
</Window.Resources>
<Button HorizontalAlignment="Center" VerticalAlignment="Center">
<Border Background="LightBlue">
<ctrls:myXamlIconHost Caption="The Caption" XamlIcon="{StaticResource TestIcon}" IconSize="XxLarge" Padding="20" />
</Border>
</Button>
</Window>

WPF Custom Base Window Class and Style

I have a an app that will open many windows, and I want all windows to look the same. I am overriding the default Windows window chrome style and making my own, so any new window that is opened (excluding messageboxes) should have the same window style. However, no matter what I seem to try it does not work. I can get it to work with one window, but when I want to make it a global style it always crashes or simply doesn't work as it should.
Here is my code:
WindowBaseStyle.xaml
<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:MyProject.Styles"
xmlns:views="clr-namespace:Myproject.Views">
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary Source="GlobalStyles.xaml" />
</ResourceDictionary.MergedDictionaries>
<Style TargetType="{x:Type views:WindowBase}" BasedOn="{StaticResource {x:Type Window}}">
<Setter Property="AllowsTransparency" Value="False" />
<Setter Property="BorderBrush" Value="Red" />
<Setter Property="BorderThickness" Value="1" />
<Setter Property="WindowState" Value="Normal" />
<Setter Property="WindowStyle" Value="SingleBorderWindow" />
<Setter Property="WindowChrome.WindowChrome">
<Setter.Value>
<WindowChrome CaptionHeight="30"
UseAeroCaptionButtons="False"/>
</Setter.Value>
</Setter>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type views:WindowBase}">
<Border BorderBrush="Blue" BorderThickness="1" SnapsToDevicePixels="True">
<DockPanel Background="White" LastChildFill="True" >
<Grid Background="Blue" DockPanel.Dock="Top">
<StackPanel HorizontalAlignment="Left" Orientation="Horizontal" VerticalAlignment="Center">
<Button Name="PART_SystemMenuButton" Command="{Binding MenuCommand}" Style="{DynamicResource SystemIconButton}">
<Image Height="16" Width="16" Source="/Resources/icon.png" Stretch="Fill"/>
</Button>
<Viewbox Height="16" HorizontalAlignment="Stretch" Margin="14,2,0,0" >
<TextBlock FontSize="12" Foreground="White" Text="{Binding Title,RelativeSource={RelativeSource FindAncestor,AncestorType=Window}}" />
</Viewbox>
</StackPanel>
<StackPanel Orientation="Horizontal" WindowChrome.IsHitTestVisibleInChrome="True">
<Button x:Name="PART_MinimizeButton" Command="{Binding MinimizeCommand}" Height="30" Margin="0,0,0,0" ToolTip="Minimize" Width="45">
<Image Source="/Resources/minimize.png" Stretch="None" />
<Button.Style>
<Style TargetType="{x:Type Button}">
<Setter Property="Background" Value="#0079CB" />
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type Button}">
<Border Background="{TemplateBinding Background}">
<ContentPresenter HorizontalAlignment="Center" VerticalAlignment="Center"/>
</Border>
</ControlTemplate>
</Setter.Value>
</Setter>
<Style.Triggers>
<Trigger Property="IsMouseOver" Value="True">
<Setter Property="Background" Value="#64AEEC"/>
</Trigger>
</Style.Triggers>
</Style>
</Button.Style>
</Button>
<Button x:Name="PART_MaximizeButton" Command="{Binding MaximizeCommand}" Height="30" Margin="0,0,0,0" Width="45">
<Image>
<Image.Style>
<Style TargetType="{x:Type Image}">
<Style.Triggers>
<DataTrigger Binding="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type Window}}, Path=WindowState}" Value="Normal">
<Setter Property="Source" Value="/Resources/maximize.png" />
<Setter Property="Stretch" Value="None" />
</DataTrigger>
<DataTrigger Binding="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type Window}}, Path=WindowState}" Value="Maximized">
<Setter Property="Source" Value="/Resources/unmaximize.png" />
<Setter Property="Stretch" Value="None" />
</DataTrigger>
</Style.Triggers>
</Style>
</Image.Style>
</Image>
<Button.Style>
<Style TargetType="{x:Type Button}">
<Setter Property="Background" Value="#0079CB" />
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type Button}">
<Border Background="{TemplateBinding Background}">
<ContentPresenter HorizontalAlignment="Center" VerticalAlignment="Center"/>
</Border>
</ControlTemplate>
</Setter.Value>
</Setter>
<Style.Triggers>
<Trigger Property="IsMouseOver" Value="True">
<Setter Property="Background" Value="#64AEEC"/>
</Trigger>
<DataTrigger Binding="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type Window}}, Path=WindowState}" Value="Normal">
<Setter Property="ToolTip" Value="Maximize" />
</DataTrigger>
<DataTrigger Binding="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type Window}}, Path=WindowState}" Value="Maximized">
<Setter Property="ToolTip" Value="Restore Down" />
</DataTrigger>
</Style.Triggers>
</Style>
</Button.Style>
</Button>
<Button x:Name="PART_CloseButton" Command="{Binding CloseCommand}" Height="30" Margin="0,0,0,0" ToolTip="Close" Width="45" >
<Image Source="/Resources/close.png" Stretch="None" />
<Button.Style>
<Style TargetType="{x:Type Button}">
<Setter Property="Background" Value="#0079CB" />
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type Button}">
<Border Background="{TemplateBinding Background}">
<ContentPresenter HorizontalAlignment="Center" VerticalAlignment="Center"/>
</Border>
</ControlTemplate>
</Setter.Value>
</Setter>
<Style.Triggers>
<Trigger Property="IsMouseOver" Value="True">
<Setter Property="Background" Value="Red"/>
</Trigger>
</Style.Triggers>
</Style>
</Button.Style>
</Button>
</StackPanel>
</StackPanel>
</Grid>
<!-- this ContentPresenter automatically binds to the content of the window -->
<ContentPresenter />
</DockPanel>
</Border>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
WindowBase.cs
using System;
using System.Runtime.InteropServices;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Interop;
namespace MyProject.Views
{
[TemplatePart(Name = "PART_MinimizeButton", Type = typeof(Button))]
[TemplatePart(Name = "PART_MaximizeButton", Type = typeof(Button))]
[TemplatePart(Name = "PART_CloseButton", Type = typeof(Button))]
[TemplatePart(Name = "PART_SystemMenuButton", Type = typeof(Button))]
public class WindowBase: Window
{
static WindowBase()
{
DefaultStyleKeyProperty.OverrideMetadata(typeof(CustomWindow), new FrameworkPropertyMetadata(typeof(CustomWindow)));
}
public WindowBase()
{
Loaded += (sender, evnt) =>
{
var MinimizeButton = (Button)Template.FindName("PART_MinimizeButton", this);
var MaximizeButton = (Button)Template.FindName("PART_MaximizeButton", this);
var CloseButton = (Button)Template.FindName("PART_CloseButton", this);
var SystemMenuButton = (Button)Template.FindName("PART_SystemMenuButton", this);
MinimizeButton.Click += (s, e) => WindowState = WindowState.Minimized;
MaximizeButton.Click += (s, e) => WindowState = WindowState == WindowState.Maximized ? WindowState.Normal : WindowState.Maximized;
CloseButton.Click += (s, e) => Close();
SystemMenuButton.Click += (s, e) => SystemCommands.ShowSystemMenu(this, GetMousePosition());
};
}
}
}
Window1.xaml
<local:WindowBase x:Class="MyProject.Views.Window1"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:MyProject.Views"
Height="750"
Width="1125">
<Grid>
</Grid>
</local:WindowBase>
Window1.xaml.cs
using System.Windows;
namespace MyProject.Views
{
/// <summary>
/// Interaction logic for Window1.xaml
/// </summary>
public partial class Window1: WindowBase
{
public Window1()
{
InitializeComponent();
}
}
}
I am overall following the MVVM pattern, and for the most part from all the articles and videos I have looked at online, they all follow this basic approach and they say it all works, but I can't seem to get it to work.
An additional note is that whenever I add my custom window control to the Window1.xaml file, it breaks the designer and says it is "Invalid Markup"
Also note I added my "WindowBaseStyle" resource dictionary to the App.xaml file as a merged resource dictionary.
Any help is greatly appreciated!! Thanks

Ok, as we discussed in the comments, it seems like the fastest solution to the problem you described is to use a StaticResource to get the window's style from a resource dictionary (or create an implicit style for windows.) I questioned the role of CustomWindow because I thought that might be causing problems with your default style override. (Remember: if you go the lookless control route and try to use the DefaultStyleKeyProperty override, you have to do this on every subclass of that control.)
However, I think doing something like this will get you reusable plumbing for multiple windows driven by viewmodels...
PopupHost
A class that would derive from your customized window. This code provides the following behaviors:
Allows the viewmodel to mark itself as having served its purpose, causing the window to close.
Allows attached properties to be specified by individual views that can affect the way the window appears on-screen, e.g. the window title.
Can be extended to notify presented items that the user has tried closing the window, allowing interception/cancellation or cleanup actions to be performed.
Code:
public class PopupHost : Window
{
private readonly AwaitableViewModelBase _viewModel;
public PopupHost(Window owner, AwaitableViewModelBase viewModel, string dataTemplateKey = null)
{
Owner = owner;
_viewModel = viewModel;
// Wrap the content in another presenter -- makes it a little easier to get to in order to look for attached properties.
var contentPresenter = new ContentPresenter
{
Content = viewModel
};
if (!string.IsNullOrWhiteSpace(dataTemplateKey))
contentPresenter.ContentTemplate = (DataTemplate) FindResource(dataTemplateKey);
Content = contentPresenter;
Task.Run(async () =>
{
await viewModel.Task;
Dispatcher.Invoke(Close);
});
Closed += ClosedHandler;
ApplyTemplate();
// Grab attached property values from the user control (or whatever element... you just need to find the descendant)
var contentElement = FindDescendantWithNonDefaultPropertyValue(contentPresenter, PopupWindowProperties.TitleProperty);
if (contentElement != null)
{
var binding = new Binding { Source = contentElement, Path = new PropertyPath(PopupWindowProperties.TitleProperty) };
SetBinding(TitleProperty, binding);
}
}
private void ClosedHandler(object sender, EventArgs args)
{
_viewModel?.Cancel();
Closed -= ClosedHandler;
}
private static Visual FindDescendant(Visual element, Predicate<Visual> predicate)
{
if (element == null)
return null;
if (predicate(element))
return element;
Visual foundElement = null;
(element as FrameworkElement)?.ApplyTemplate();
for (int i = 0; i < VisualTreeHelper.GetChildrenCount(element); i++)
{
var visual = VisualTreeHelper.GetChild(element, i) as Visual;
foundElement = FindDescendant(visual, predicate);
if (foundElement != null)
break;
}
return foundElement;
}
private static Visual FindDescendantWithNonDefaultPropertyValue(Visual element, DependencyProperty dp)
{
return FindDescendant(element, e => !(dp.GetMetadata(e).DefaultValue ?? new object()).Equals(e.GetValue(dp)));
}
}
PopupWindowProperties
Just a dumb object containing solely attached properties so your views can convey some information to the window.
public static class PopupWindowProperties
{
public static readonly DependencyProperty TitleProperty = DependencyProperty.RegisterAttached("Title", typeof(string), typeof(PopupWindowProperties), new FrameworkPropertyMetadata(string.Empty));
public static void SetTitle(UIElement element, string value) => element.SetValue(TitleProperty, value);
public static string GetTitle(UIElement element) => element.GetValue(TitleProperty) as string;
}
AwaitableViewModelBase
A simple abstract viewmodel which has a TaskCompletionSource. This allows the popup window and the viewmodel to coordinate closing.
public abstract class AwaitableViewModelBase : ViewModelBase
{
protected TaskCompletionSource<bool> TaskCompletionSource { get; set; }
public Task<bool> Task => TaskCompletionSource?.Task;
public void RegisterTaskCompletionSource(TaskCompletionSource<bool> tcs)
{
var current = TaskCompletionSource;
if (current != null && current.Task.Status == TaskStatus.Running)
throw new InvalidOperationException();
TaskCompletionSource = tcs;
}
public virtual void Cancel() => SetResult(false);
protected void SetResult(bool result) => TaskCompletionSource?.TrySetResult(result);
}
WindowService
Last but not least, the simple service that can present the requested view and viewmodel. You can use implicit DataTemplates for your viewmodels, or provide the specific x:Key value of the template you wish to use. Note that the await doesn't really do anything here because ShowDialog blocks. We return the bool since it can be used to easily identify if the user hit OK or Cancel on a modal.
public class WindowService
{
public async Task<bool> ShowModalAsync(AwaitableViewModelBase viewModel, string dataTemplateKey = null)
{
var tcs = new TaskCompletionSource<bool>();
viewModel.RegisterTaskCompletionSource(tcs);
Application.Current.Dispatcher.Invoke(() =>
{
var currentWindow = Application.Current.Windows.OfType<Window>().SingleOrDefault(x => x.IsActive) ?? Application.Current.MainWindow;
var window = new PopupHost(currentWindow, viewModel, dataTemplateKey);
window.ShowDialog();
});
return await viewModel.Task;
}
}

Sliding text in combobox

I would like to slide the text (marquee text) of the selected item in a combobox, if it's lenght is bigger than the width of the combobox. It can be either automatical or when the user put the mouse over the combobox. The problem is that i have absolutely no idea on how to do that. It's maybe possible to do that with a render transform (previous definition of a textblock inside it)? or with a storyboard?
Here is the xaml that i need to modify
<DataGrid.ColumnHeaderStyle>
<Style TargetType="{x:Type DataGridColumnHeader}">
<Setter Property="ContentTemplate" >
<Setter.Value>
<DataTemplate DataType="DataGridColumnHeader" >
<ComboBox ItemContainerStyle="{StaticResource SingleSelectionComboBoxItem}" DisplayMemberPath="Oggetto" Width="100" Height="20" ItemsSource="{Binding RelativeSource={RelativeSource AncestorType={x:Type DataGrid}},Path=DataContext.Selezione, UpdateSourceTrigger=LostFocus}" SelectionChanged="SingleSelectionComboBox_SelectionChanged"/>
</DataTemplate>
</Setter.Value>
</Setter>
</Style>
</DataGrid.ColumnHeaderStyle>
EDIT: the problem is that i don't know which properties should i target in the storyboard
EDIT2: i took the template of the combobox and modified the text box section like this :
<Style x:Key="ComboBoxEditableTextBox" TargetType="{x:Type TextBox}">
<Style.Triggers>
<EventTrigger RoutedEvent="MouseEnter">
<EventTrigger.Actions>
<BeginStoryboard>
<Storyboard>
<DoubleAnimation From="0" To="100" Duration="00:00:10" Storyboard.TargetProperty="X" Storyboard.TargetName="transferCurreny" RepeatBehavior="Forever" />
</Storyboard>
</BeginStoryboard>
</EventTrigger.Actions>
</EventTrigger>
</Style.Triggers>
<Setter Property="RenderTransform">
<Setter.Value>
<TranslateTransform x:Name="transferCurreny" X="0"/>
</Setter.Value>
</Setter>
The problem is that this seems to have no effect
EDIT 3: i realized that i had to use the template that use the style i mentioned above
<ControlTemplate x:Key="ComboBoxEditableTemplate" TargetType="{x:Type ComboBox}">
<Grid x:Name="Placement" SnapsToDevicePixels="true">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*" />
<ColumnDefinition Width="Auto" />
</Grid.ColumnDefinitions>
<Popup x:Name="PART_Popup" AllowsTransparency="true" Grid.ColumnSpan="2"
IsOpen="{Binding IsDropDownOpen, RelativeSource={RelativeSource TemplatedParent}}"
PopupAnimation="{DynamicResource {x:Static SystemParameters.ComboBoxPopupAnimationKey}}"
Placement="Bottom">
<Themes:SystemDropShadowChrome x:Name="Shdw" Color="Transparent"
MaxHeight="{TemplateBinding MaxDropDownHeight}"
MinWidth="{Binding ActualWidth, ElementName=Placement}">
<Border x:Name="DropDownBorder"
BorderBrush="{DynamicResource {x:Static SystemColors.WindowFrameBrushKey}}"
BorderThickness="1" Background="{DynamicResource {x:Static SystemColors.WindowBrushKey}}">
<ScrollViewer x:Name="DropDownScrollViewer">
<Grid RenderOptions.ClearTypeHint="Enabled">
<Canvas HorizontalAlignment="Left" Height="0" VerticalAlignment="Top" Width="0">
<Rectangle x:Name="OpaqueRect"
Fill="{Binding Background, ElementName=DropDownBorder}"
Height="{Binding ActualHeight, ElementName=DropDownBorder}"
Width="{Binding ActualWidth, ElementName=DropDownBorder}" />
</Canvas>
<ItemsPresenter x:Name="ItemsPresenter"
KeyboardNavigation.DirectionalNavigation="Contained"
SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" />
</Grid>
</ScrollViewer>
</Border>
</Themes:SystemDropShadowChrome>
</Popup>
<Themes:ListBoxChrome x:Name="Border" BorderBrush="{TemplateBinding BorderBrush}"
BorderThickness="{TemplateBinding BorderThickness}"
Background="{TemplateBinding Background}" Grid.ColumnSpan="2"
RenderMouseOver="{TemplateBinding IsMouseOver}"
RenderFocused="{TemplateBinding IsKeyboardFocusWithin}" />
<TextBox x:Name="PART_EditableTextBox"
HorizontalContentAlignment="{TemplateBinding HorizontalContentAlignment}"
IsReadOnly="{Binding IsReadOnly, RelativeSource={RelativeSource TemplatedParent}}"
Margin="{TemplateBinding Padding}" Style="{StaticResource ComboBoxEditableTextBox}"
VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}" >
</TextBox>
<ToggleButton Grid.Column="1"
IsChecked="{Binding IsDropDownOpen, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}"
Style="{StaticResource ComboBoxToggleButton}" />
</Grid>
<ControlTemplate.Triggers>
<Trigger Property="IsKeyboardFocusWithin" Value="true">
<Setter Property="Foreground" Value="Black" />
</Trigger>
<Trigger Property="IsDropDownOpen" Value="true">
<Setter Property="RenderFocused" TargetName="Border" Value="true" />
</Trigger>
<Trigger Property="HasItems" Value="false">
<Setter Property="Height" TargetName="DropDownBorder" Value="95" />
</Trigger>
<Trigger Property="IsEnabled" Value="false">
<Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.GrayTextBrushKey}}" />
<Setter Property="Background" Value="#FFF4F4F4" />
</Trigger>
<MultiTrigger>
<MultiTrigger.Conditions>
<Condition Property="IsGrouping" Value="true" />
<Condition Property="VirtualizingPanel.IsVirtualizingWhenGrouping" Value="false" />
</MultiTrigger.Conditions>
<Setter Property="ScrollViewer.CanContentScroll" Value="false" />
</MultiTrigger>
<Trigger Property="HasDropShadow" SourceName="PART_Popup" Value="true">
<Setter Property="Margin" TargetName="Shdw" Value="0,0,5,5" />
<Setter Property="Color" TargetName="Shdw" Value="#71000000" />
</Trigger>
<Trigger Property="ScrollViewer.CanContentScroll" SourceName="DropDownScrollViewer" Value="false">
<Setter Property="Canvas.Top" TargetName="OpaqueRect"
Value="{Binding VerticalOffset, ElementName=DropDownScrollViewer}" />
<Setter Property="Canvas.Left" TargetName="OpaqueRect"
Value="{Binding HorizontalOffset, ElementName=DropDownScrollViewer}" />
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
the textbox section is the one that use the style. However when i do Template="{StaticResource ComboBoxEditableTemplate}" in the combobox, i cannot see the selected item anymore, even if it's not null

Updated 08/02
Basically in order to avoid the animation issues you are facing - you will need to add a ScrollViewer as a wrapper to the content-site or selection-box TextBlock. You can either do that by using a custom template selector for your ComboBox so as defined below, or provide a custom item-template with ScollViewer.
Secondly, you can either create a custom ComboBox control in C# to bind the above template-selector/item-template and apply slide-animation on MouseEnterEvent; or implement the same in XAML itself.
For this example - have implemented the control in C#, and provided
a sample usage in XAML.
Code for custom control, and template selector
public class SlidingComboBox : ComboBox
{
public static readonly DependencyProperty SlideForeverProperty = DependencyProperty.Register("SlideForever", typeof(bool), typeof(SlidingComboBox), new FrameworkPropertyMetadata(false));
public bool SlideForever
{
get { return (bool)GetValue(SlideForeverProperty); }
set { SetValue(SlideForeverProperty, value); }
}
protected ContentPresenter _parent;
protected DoubleAnimation _animation;
protected TranslateTransform _translate;
protected Storyboard _storyBoard;
public SlidingComboBox()
{
Loaded += ExComboBox_Loaded;
ClipToBounds = true;
//assign template selector - just to re-template ContentSite / selection box
//uncomment this code - if you want to default-template for popup-items
//ItemTemplateSelector = new SlidingComboBoxItemTemplateSelector();
}
private void ExComboBox_Loaded(object sender, RoutedEventArgs e)
{
Loaded -= ExComboBox_Loaded;
//get content-site holder/parent
_parent = this.GetChildOfType<ContentPresenter>();
//setup slide animation
_animation = new DoubleAnimation()
{
From = 0,
RepeatBehavior = SlideForever ? RepeatBehavior.Forever : new RepeatBehavior(1), //repeat only if slide-forever is true
AutoReverse = SlideForever
};
//create storyboard
_storyBoard = new Storyboard();
_storyBoard.Children.Add(_animation);
Storyboard.SetTargetProperty(_animation, new PropertyPath("RenderTransform.(TranslateTransform.X)"));
}
protected override void OnMouseEnter(MouseEventArgs e)
{
//get actual textblock that renders the selected value
var textBlock = _parent.GetChildOfType<TextBlock>();
//and translate-transform for animation
textBlock.RenderTransform = _translate = new TranslateTransform();
//start animation only if text-block width is greater than parent
if (_parent.ActualWidth < textBlock.ActualWidth)
{
_animation.Duration = TimeSpan.FromMilliseconds(((int)textBlock.Text?.Length * 100));
_animation.To = _parent.ActualWidth - textBlock.ActualWidth;
_storyBoard.Begin(textBlock);
}
base.OnMouseEnter(e);
}
protected override void OnMouseLeave(MouseEventArgs e)
{
//stop animation once mouse pointer is off the control
_storyBoard.Stop();
//reset render state
var textBlock = _parent.GetChildOfType<TextBlock>();
textBlock.RenderTransform = _translate = new TranslateTransform();
base.OnMouseLeave(e);
}
}
public class SlidingComboBoxItemTemplateSelector : DataTemplateSelector
{
DataTemplate _selectedItemTemplate;
public SlidingComboBoxItemTemplateSelector()
{
//create datatemplate with ScrollViewer and TextBlock as child
var textBlock = new FrameworkElementFactory(typeof(TextBlock));
textBlock.SetValue(TextBlock.TextWrappingProperty, TextWrapping.NoWrap);
textBlock.SetBinding(TextBlock.TextProperty, new Binding("SelectedValue")
{
RelativeSource = new RelativeSource { Mode = RelativeSourceMode.FindAncestor, AncestorType = typeof(ComboBox) }
});
var scrollViewer = new FrameworkElementFactory(typeof(ScrollViewer));
scrollViewer.SetValue(ScrollViewer.CanContentScrollProperty, true);
scrollViewer.SetValue(ScrollViewer.HorizontalScrollBarVisibilityProperty, ScrollBarVisibility.Hidden);
scrollViewer.SetValue(ScrollViewer.VerticalScrollBarVisibilityProperty, ScrollBarVisibility.Disabled);
scrollViewer.AppendChild(textBlock);
_selectedItemTemplate = new DataTemplate
{
VisualTree = scrollViewer
};
}
public override DataTemplate SelectTemplate(object item, DependencyObject container)
{
ComboBoxItem comboBoxItem = container.GetVisualParent<ComboBoxItem>();
if (comboBoxItem == null)
{
//send back only if template requested for ContentSite, and not for combo-box item(s)
return _selectedItemTemplate;
}
return null;
}
}
/// <summary>
/// VisualTree helper
/// </summary>
public static class HelperExtensions
{
public static T GetChildOfType<T>(this DependencyObject depObj) where T : DependencyObject
{
if (depObj == null) return null;
for (int i = 0; i < VisualTreeHelper.GetChildrenCount(depObj); i++)
{
var child = VisualTreeHelper.GetChild(depObj, i);
var result = (child as T) ?? GetChildOfType<T>(child);
if (result != null) return result;
}
return null;
}
public static T GetVisualParent<T>(this DependencyObject child) where T : Visual
{
while ((child != null) && !(child is T))
{
child = VisualTreeHelper.GetParent(child);
}
return child as T;
}
}
Sample usage:
<Window x:Class="MarqueeSample.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local="clr-namespace:MarqueeSample"
xmlns:sys="clr-namespace:System;assembly=mscorlib"
xmlns:col="clr-namespace:System.Collections;assembly=mscorlib"
mc:Ignorable="d"
Title="MainWindow" Height="200" Width="400">
<Grid Margin="20">
<DataGrid AutoGenerateColumns="False" IsReadOnly="True" Width="225" VerticalAlignment="Center">
<DataGrid.ItemsSource>
<col:Hashtable>
<col:ArrayList x:Key="TestData1">
<sys:String>Tiny</sys:String>
<sys:String>Keep calm and love programming</sys:String>
</col:ArrayList>
<col:ArrayList x:Key="TestData2">
<sys:String>Sample string</sys:String>
<sys:String>Another string to test</sys:String>
</col:ArrayList>
</col:Hashtable>
</DataGrid.ItemsSource>
<DataGrid.Columns>
<DataGridTextColumn Header="Name" Width="100" Binding="{Binding Key}" />
<DataGridTemplateColumn Header="Value" Width="100">
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<local:SlidingComboBox ItemsSource="{Binding Value}">
<local:SlidingComboBox.ItemTemplate>
<DataTemplate>
<ScrollViewer CanContentScroll="True" HorizontalScrollBarVisibility="Hidden" VerticalScrollBarVisibility="Disabled">
<TextBlock Text="{Binding}" />
</ScrollViewer>
</DataTemplate>
</local:SlidingComboBox.ItemTemplate>
</local:SlidingComboBox>
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>
</DataGrid.Columns>
</DataGrid>
</Grid>
</Window>
You can also use SlideForever property to manipulate RepeatBehaviour.
<local:SlidingComboBox ItemsSource="{Binding Value}" SlideForever="True" />

I've been looking into this and I think I have your solution. You should combine both a RenderTransform and a Storyboard on the ComboBox ContentPresenter (this is what displays the currently selected item)
<ComboBox Grid.Row="1" Name="MyComboBox" Width="200">
<ComboBox.Resources>
<Style TargetType="ContentPresenter">
<Setter Property="RenderTransform">
<Setter.Value>
<TranslateTransform X="0" Y="0" />
</Setter.Value>
</Setter>
<Style.Triggers>
<EventTrigger RoutedEvent="Window.Loaded">
<EventTrigger.Actions>
<BeginStoryboard x:Name="ScrollItem">
<Storyboard RepeatBehavior="Forever">
<DoubleAnimation Duration="00:00:5" From="0" To="200" Storyboard.TargetProperty="RenderTransform.(TranslateTransform.X)" />
<DoubleAnimation Duration="00:00:5" BeginTime="00:00:5" From="-200" To="0" Storyboard.TargetProperty="RenderTransform.(TranslateTransform.X)" />
</Storyboard>
</BeginStoryboard>
</EventTrigger.Actions>
</EventTrigger>
</Style.Triggers>
</Style>
</ComboBox.Resources>
<ComboBoxItem>
I am combobox value 1
</ComboBoxItem>
<ComboBoxItem>
I am combobox value 2, Hello!
</ComboBoxItem>
</ComboBox>
Having the ComboBox of size 200, scrolling from 0 to 200, then -200 to 0, scrolls the text off the right hand side of the control, and in the left hand side. (You can drop the 2nd DoubleAnimation if you like and set AutoReverse to True to cause the text to bounce back in if you'd rather that. This does not code you around items that are too big for the control, you will need to write some code for the ComboBox so it decides if the currently selected Item is too big, and from code behind (or maybe a custom ComboBox Class) dynamically turn on/off the storyboard.

First iterate through all items of your combobox, check for the width of every items by assigning the text to a label. Then, check width every time, if width of current item gets greater than previous items then change the maximum width.
int DropDownWidth(ComboBox myCombo)
{
int maxWidth = 0;
int temp = 0;
Label label1 = new Label();
foreach (var obj in myCombo.Items)
{
label1.Text = obj.ToString();
temp = label1.PreferredWidth;
if (temp > maxWidth)
{
maxWidth = temp;
}
}
label1.Dispose();
return maxWidth;
}
private void window_loaded(object sender, EventArgs e)
{
comboBox1.DropDownWidth = DropDownWidth(comboBox1);
}
OR
int DropDownWidth(ComboBox myCombo)
{
int maxWidth = 0, temp = 0;
foreach (var obj in myCombo.Items)
{
temp = TextRenderer.MeasureText(obj.ToString(), myCombo.Font).Width;
if (temp > maxWidth)
{
maxWidth = temp;
}
}
return maxWidth;
}
Thanks to those guys got it from here --> Auto-width of ComboBox's content

XAML How apply styles according the value of paramter

The goal is to check the state of parameters, the state of each parameter can take the enum value (lock, unlock, or valueIncorrect). The display
will be different according to the state of the parameter(e.g, lock rectangle will be red, unlock the text will be bold and vallueIncorrect will be gray).
In main class we have different parameters VarA, VarB and VarC for example. The state of each parameter can be different.
enum State{lock, unlock, valueIncorrect};
State VarA = lock
State VarB = unlock
State VarC = lock
before I was this style and a rectangle based on this style and When I pressed a button , the style will change, but the reaction will be the same on all parameter
<Style x:Key="DisplayLockGroup" TargetType="GroupBox">
<Setter Property="BorderThickness" Value="2"/>
<Style.Triggers>
<DataTrigger Binding="{Binding Source={x:Static local:LockMgt.Instance}, Path=isLocked}" Value="true">
<Setter Property="BorderBrush" Value="Red" />
</DataTrigger>
<DataTrigger Binding="{Binding Source={x:Static local:LockMgt.Instance}, Path=isLocked}" Value="false">
<Setter Property="BorderBrush" Value="Green" />
</DataTrigger>
</Style.Triggers>
</Style>
<Rectangle x:Name="r_LockEcuTypes" Grid.Row="5" Grid.RowSpan="3" Grid.Column ="1" Grid.ColumnSpan="7" Style="{DynamicResource DisplayLockRectangleGroup}" />
Now i would like to change this behavior, I have different parameter and I would like to individually check the state of this parameter and apply one style according to the value, but i don't know How I can do it.
E.g for one parameter:
State VarA=lock => i would like to apply the style1
State VarB=unlock => i would like to apply the style2
State VarC=lock => i would like to apply the style1 but if the value change from lock to unlock, I would like to apply the style2
I don't know how create the XAML to display correctly what is expected.

As commented, depending on your actual needs, you have several options.
Converter from State to some property value
Change the properties via Style.Triggers (similar to your current approach)
Wrap your control and exchange inner styles via ControlTemplate.Triggers on the wrapper control
The following example is presenting three rectangles (rect1, rect2 and rect3 representing the approach with the same number) and a button that is responsible for changing the State of the ViewModel object in order to show how each rectangle reacts.
The XAML
<Window x:Class="WpfApplication2.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:WpfApplication2"
Title="MainWindow" Height="350" Width="525"
Loaded="Window_Loaded">
<Window.Resources>
<!-- Used for 1. -->
<local:StateToBorderBrushConverter x:Key="stateConverter"/>
<!-- Used for 2. -->
<Style x:Key="DisplayLockGroup" TargetType="Rectangle">
<Setter Property="StrokeThickness" Value="2"/>
<Style.Triggers>
<DataTrigger Binding="{Binding Data1State}" Value="{x:Static local:State.locked}">
<Setter Property="Stroke" Value="Red" />
</DataTrigger>
<DataTrigger Binding="{Binding Data1State}" Value="{x:Static local:State.unlock}">
<Setter Property="Stroke" Value="Green" />
</DataTrigger>
</Style.Triggers>
</Style>
<!-- Used for 3. -->
<Style x:Key="DefaultRectangleStyle" TargetType="Rectangle">
<Setter Property="StrokeThickness" Value="2"/>
</Style>
<Style x:Key="LockedRectangleStyle" TargetType="Rectangle">
<Setter Property="StrokeThickness" Value="2"/>
<Setter Property="Stroke" Value="Red" />
</Style>
<Style x:Key="UnlockedRectangleStyle" TargetType="Rectangle">
<Setter Property="StrokeThickness" Value="2"/>
<Setter Property="Stroke" Value="Green" />
</Style>
</Window.Resources>
<Grid x:Name="grid1">
<Grid.RowDefinitions>
<RowDefinition />
<RowDefinition />
<RowDefinition />
<RowDefinition />
</Grid.RowDefinitions>
<Rectangle x:Name="rect1" Grid.Row="0" Margin="5" StrokeThickness="2" Stroke="{Binding Data1State,Converter={StaticResource stateConverter}}" />
<Rectangle x:Name="rect2" Grid.Row="1" Margin="5" Style="{StaticResource DisplayLockGroup}" />
<ContentControl Margin="5" Grid.Row="2">
<ContentControl.Template>
<ControlTemplate TargetType="ContentControl">
<Rectangle x:Name="rect3" Style="{StaticResource DefaultRectangleStyle}" />
<ControlTemplate.Triggers>
<DataTrigger Binding="{Binding Data1State}" Value="{x:Static local:State.locked}">
<Setter TargetName="rect3" Property="Style" Value="{StaticResource LockedRectangleStyle}"/>
</DataTrigger>
<DataTrigger Binding="{Binding Data1State}" Value="{x:Static local:State.unlock}">
<Setter TargetName="rect3" Property="Style" Value="{StaticResource UnlockedRectangleStyle}"/>
</DataTrigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</ContentControl.Template>
</ContentControl>
<Button x:Name="ChangeStateButton" Grid.Row="3" Margin="5" VerticalAlignment="Center" Content="Change State" Click="ChangeStateButton_Click"/>
</Grid>
</Window>
The Code
namespace WpfApplication2
{
public enum State
{
locked,
unlock,
valueIncorrect
}
public class BaseViewModel : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
protected void NotifyPropertyChanged([CallerMemberName] string prop = null)
{
var handler = PropertyChanged;
if (handler != null)
{
handler(this, new PropertyChangedEventArgs(prop));
}
}
}
public class MyData : BaseViewModel
{
private State _Data1State;
public State Data1State
{
get { return _Data1State; }
set
{
if (_Data1State != value)
{
_Data1State = value;
NotifyPropertyChanged();
}
}
}
}
public class StateToBorderBrushConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
if (value is State)
{
var s = (State)value;
switch (s)
{
case State.locked:
return new SolidColorBrush(Colors.Red);
case State.unlock:
return new SolidColorBrush(Colors.Green);
case State.valueIncorrect:
return new SolidColorBrush(Colors.White);
default:
break;
}
}
return new SolidColorBrush(Colors.Transparent);
}
public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
throw new NotImplementedException();
}
}
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
}
private MyData ContextData;
private void Window_Loaded(object sender, RoutedEventArgs e)
{
ContextData = new MyData { Data1State = State.locked };
grid1.DataContext = ContextData;
}
private void ChangeStateButton_Click(object sender, RoutedEventArgs e)
{
switch (ContextData.Data1State)
{
case State.locked:
ContextData.Data1State = State.unlock;
break;
case State.unlock:
ContextData.Data1State = State.valueIncorrect;
break;
case State.valueIncorrect:
ContextData.Data1State = State.locked;
break;
default:
ContextData.Data1State = State.locked;
break;
}
}
}
}
Pros and cons:
The converter approach is useful, if the same property type is targeted in many different control types. The converter is returning a Brush and it doesn't care whether that brush will be used in a Rectangle.Stroke, a Border.BorderBrush or some other context.
The style trigger approach is less flexible regarding the targeted control type, but it is easier to maintain changes of more than a single property based on the status.
The control template trigger approach is useful in some advanced scenarios. It allows separate definition of the styles for each state. However, I'd only recommend it if you actually derive your own custom control with additional functionality, not as an ad-hoc control template just for switching styles.

You can apply an enum to color converter in the XAML binding
Background="{Binding Source=StateValue,
Converter={StaticResource stateValueColorConverter}}"
You'll easily find the detailed documentation: this is to give you the main idea of the usage.

Thanks to grek40, it is exactly what I want. I have try the option 3 and 2 and it works fine, I have use the case 2, it is most easily to implement.
I have use the same behavior for add an image on lock and unlock state.

In the Xaml.cs file, How I can access to parameter rect3 on your proposal, when I try it I have compilation error "the name "rect3" does not exist in the current view, I have written
XAML.CS :
rect3.Visibility = Visibility.Collapsed;
XAML :
<ContentControl Grid.RowSpan="3" Grid.ColumnSpan="3" KeyboardNavigation.IsTabStop="False">
<ContentControl.Template>
<ControlTemplate TargetType="ContentControl">
<Rectangle x:Name="rect3" Style="{StaticResource DefaultRectangleStyle}" />
<ControlTemplate.Triggers>
<DataTrigger Binding="{Binding Data1State}" Value="{x:Static local:State.locked}">
<Setter TargetName="rect3" Property="Style" Value="{StaticResource LockedRectangleStyle}"/>
</DataTrigger>
<DataTrigger Binding="{Binding Data1State}" Value="{x:Static local:State.unlock}">
<Setter TargetName="rect3" Property="Style" Value="{StaticResource UnlockedRectangleStyle}"/>
</DataTrigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</ContentControl.Template>
</ContentControl>

How can I bind to an attached property in a Style.Resource?

I'm trying to create a prompt text label in the background of a TextBox using attached properties, but I can't resolve the binding to the text caption in a style resource:
Style definition:
<Style x:Key="CueBannerTextBoxStyle"
TargetType="TextBox">
<Style.Resources>
<VisualBrush x:Key="CueBannerBrush"
AlignmentX="Left"
AlignmentY="Center"
Stretch="None">
<VisualBrush.Visual>
<Label Content="{Binding Path=(EnhancedControls:CueBannerTextBox.Caption), RelativeSource={RelativeSource AncestorType={x:Type TextBox}}}"
Foreground="LightGray"
Background="White"
Width="200" />
</VisualBrush.Visual>
</VisualBrush>
</Style.Resources>
<Style.Triggers>
<Trigger Property="Text"
Value="{x:Static sys:String.Empty}">
<Setter Property="Background"
Value="{DynamicResource CueBannerBrush}" />
</Trigger>
<Trigger Property="Text"
Value="{x:Null}">
<Setter Property="Background"
Value="{DynamicResource CueBannerBrush}" />
</Trigger>
<Trigger Property="IsKeyboardFocused"
Value="True">
<Setter Property="Background"
Value="White" />
</Trigger>
</Style.Triggers>
</Style>
Attached property:
public class CueBannerTextBox
{
public static String GetCaption(DependencyObject obj)
{
return (String)obj.GetValue(CaptionProperty);
}
public static void SetCaption(DependencyObject obj, String value)
{
obj.SetValue(CaptionProperty, value);
}
public static readonly DependencyProperty CaptionProperty =
DependencyProperty.RegisterAttached("Caption", typeof(String), typeof(CueBannerTextBox), new UIPropertyMetadata(null));
}
Usage:
<TextBox x:Name="txtProductInterfaceStorageId"
EnhancedControls:CueBannerTextBox.Caption="myCustomCaption"
Width="200"
Margin="5"
Style="{StaticResource CueBannerTextBoxStyle}" />
The idea is that you can define the text prompt used in the visual brush when you create the textbox, but I'm getting a binding error:
System.Windows.Data Error: 4 : Cannot find source for binding with reference 'RelativeSource FindAncestor, AncestorType='System.Windows.Controls.TextBox', AncestorLevel='1''. BindingExpression:Path=(0); DataItem=null; target element is 'Label' (Name=''); target property is 'Content' (type 'Object')
The code works fine if I just hardcode the Label.Content property in the style.
Any ideas?

The problem here has to do with the way Style works: basically, one "copy" of the Style will be created (at first reference), and at that point, there may be multiple TextBox controls you want this Style applied to - which one will it use for the RelativeSource?
The (probable) answer is to use a Template instead of a Style - with a control or data template, you'll be able to access the visual tree of the TemplatedParent, and that should get you where you need to be.
EDIT: On further thought, I may be incorrect here...I'll throw together a quick test harness when I'm back in front of a computer and see if I can prove/disprove this.
FURTHER EDIT: While what I originally said was arguably "true", that's not your problem; What Raul said re: the visual tree is correct:
You are setting the Background property on the TextBox to a VisualBrush instance.
The Visual of that brush is not mapped into the Visual Tree of the control.
As a result, any {RelativeSource FindAncestor} navigation will fail, as the parent of that visual will be null.
This is the case regardless of whether it is declared as a Style or a ControlTemplate.
All that said, relying on ElementName definitely is non-ideal, as it reduces the reusability of the definition.
So, what to do?
I've been wracking my brain overnight trying to think of a way to marshal over the proper inheritance context to the contained brush, with little success...I did come up with this super-hacky way, however:
First, the helper property (note: I don't usually style my code this way, but trying to save space):
public class HackyMess
{
public static String GetCaption(DependencyObject obj)
{
return (String)obj.GetValue(CaptionProperty);
}
public static void SetCaption(DependencyObject obj, String value)
{
Debug.WriteLine("obj '{0}' setting caption to '{1}'", obj, value);
obj.SetValue(CaptionProperty, value);
}
public static readonly DependencyProperty CaptionProperty =
DependencyProperty.RegisterAttached("Caption", typeof(String), typeof(HackyMess),
new FrameworkPropertyMetadata(null));
public static object GetContext(DependencyObject obj) { return obj.GetValue(ContextProperty); }
public static void SetContext(DependencyObject obj, object value) { obj.SetValue(ContextProperty, value); }
public static void SetBackground(DependencyObject obj, Brush value) { obj.SetValue(BackgroundProperty, value); }
public static Brush GetBackground(DependencyObject obj) { return (Brush) obj.GetValue(BackgroundProperty); }
public static readonly DependencyProperty ContextProperty = DependencyProperty.RegisterAttached(
"Context", typeof(object), typeof(HackyMess),
new FrameworkPropertyMetadata(default(HackyMess), FrameworkPropertyMetadataOptions.OverridesInheritanceBehavior | FrameworkPropertyMetadataOptions.Inherits));
public static readonly DependencyProperty BackgroundProperty = DependencyProperty.RegisterAttached(
"Background", typeof(Brush), typeof(HackyMess),
new UIPropertyMetadata(default(Brush), OnBackgroundChanged));
private static void OnBackgroundChanged(DependencyObject obj, DependencyPropertyChangedEventArgs args)
{
var rawValue = args.NewValue;
if (rawValue is Brush)
{
var brush = rawValue as Brush;
var previousContext = obj.GetValue(ContextProperty);
if (previousContext != null && previousContext != DependencyProperty.UnsetValue)
{
if (brush is VisualBrush)
{
// If our hosted visual is a framework element, set it's data context to our inherited one
var currentVisual = (brush as VisualBrush).GetValue(VisualBrush.VisualProperty);
if(currentVisual is FrameworkElement)
{
(currentVisual as FrameworkElement).SetValue(FrameworkElement.DataContextProperty, previousContext);
}
}
}
// Why can't there be just *one* background property? *sigh*
if (obj is TextBlock) { obj.SetValue(TextBlock.BackgroundProperty, brush); }
else if (obj is Control) { obj.SetValue(Control.BackgroundProperty, brush); }
else if (obj is Panel) { obj.SetValue(Panel.BackgroundProperty, brush); }
else if (obj is Border) { obj.SetValue(Border.BackgroundProperty, brush); }
}
}
}
And now the updated XAML:
<Style x:Key="CueBannerTextBoxStyle"
TargetType="{x:Type TextBox}">
<Style.Triggers>
<Trigger Property="TextBox.Text"
Value="{x:Static sys:String.Empty}">
<Setter Property="local:HackyMess.Background">
<Setter.Value>
<VisualBrush AlignmentX="Left"
AlignmentY="Center"
Stretch="None">
<VisualBrush.Visual>
<Label Content="{Binding Path=(local:HackyMess.Caption)}"
Foreground="LightGray"
Background="White"
Width="200" />
</VisualBrush.Visual>
</VisualBrush>
</Setter.Value>
</Setter>
</Trigger>
<Trigger Property="IsKeyboardFocused"
Value="True">
<Setter Property="local:HackyMess.Background"
Value="White" />
</Trigger>
</Style.Triggers>
</Style>
<TextBox x:Name="txtProductInterfaceStorageId"
local:HackyMess.Caption="myCustomCaption"
local:HackyMess.Context="{Binding RelativeSource={RelativeSource Self}}"
Width="200"
Margin="5"
Style="{StaticResource CueBannerTextBoxStyle}" />
<TextBox x:Name="txtProductInterfaceStorageId2"
local:HackyMess.Caption="myCustomCaption2"
local:HackyMess.Context="{Binding RelativeSource={RelativeSource Self}}"
Width="200"
Margin="5"
Style="{StaticResource CueBannerTextBoxStyle}" />

The problem is that the Label inside the VisualBrush is not a visual child of the TextBox, that is the reason why that binding doesn't work. My solution for that problem will be using the ElementName binding. But the visual brush you are creating is inside a Style's dictionary resource and then the ElementName binding will not work because doesn't find the element id. The solution for that will be to create the VisualBrush in a global dictionary resources. See this XAML code for delcaring the VisualBrush:
<Window.Resources>
<VisualBrush x:Key="CueBannerBrush"
AlignmentX="Left"
AlignmentY="Center"
Stretch="None">
<VisualBrush.Visual>
<Label Content="{Binding Path=(EnhancedControls:CueBannerTextBox.Caption), ElementName=txtProductInterfaceStorageId}"
Foreground="#4F48DD"
Background="#B72121"
Width="200"
Height="200" />
</VisualBrush.Visual>
</VisualBrush>
<Style x:Key="CueBannerTextBoxStyle"
TargetType="{x:Type TextBox}">
<Style.Triggers>
<Trigger Property="Text"
Value="{x:Static System:String.Empty}">
<Setter Property="Background"
Value="{DynamicResource CueBannerBrush}" />
</Trigger>
<Trigger Property="Text"
Value="{x:Null}">
<Setter Property="Background"
Value="{DynamicResource CueBannerBrush}" />
</Trigger>
<Trigger Property="IsKeyboardFocused"
Value="True">
<Setter Property="Background"
Value="White" />
</Trigger>
</Style.Triggers>
</Style>
</Window.Resources>
This code should works. No more code need to be changed so I'm not rewriting all the code.
Hope this solution works for you...

Develop Reference

C# (C-Sharp) is a programming language developed by Microsoft that runs on the .NET Framework.

Must have non-null value for 'Binding' problem - c#

Related

Change button appearance/icon

WPF Custom Base Window Class and Style

Sliding text in combobox

XAML How apply styles according the value of paramter

How can I bind to an attached property in a Style.Resource?

Categories

Resources