.NET MAUI: Dynamic behaviour of graphic elements when using MVVM - c#

For the animation of UI elements like a progress bar, even in Microsofts documentation, there are always suggestions that (only) work from code behind, like this:
await progressBar.ProgressTo(0.75, 500, Easing.Linear);
I could not find a way to do this from a ViewModel, as it is not possible (and not intended) to access XAML elements from there. I tried to this with data binding, using BindableProperty. Could not get it to work. So, am I holding it wrong, or is it not possible?
I created a Drawable class:
public class ProgressArcDrawable : GraphicsView, IDrawable
{
public double ArcProgress
{
get => (double)GetValue(ArcProgressProperty);
set => SetValue(ArcProgressProperty, value);
}
public float Stroke
{
get => (float)GetValue(StrokeProperty);
set => SetValue(StrokeProperty, value);
}
public Color ArcColor
{
get => (Color)GetValue(ArcColorProperty);
set => SetValue(ArcColorProperty, value);
}
public static readonly BindableProperty ArcProgressProperty =
BindableProperty.Create(nameof(ArcProgress), typeof(double), typeof(ProgressArcDrawable));
public static readonly BindableProperty StrokeProperty =
BindableProperty.Create(nameof(Stroke), typeof(float), typeof(ProgressArcDrawable));
public static readonly BindableProperty ArcColorProperty =
BindableProperty.Create(nameof(ArcColor), typeof(Color), typeof(ProgressArcDrawable));
public void Draw(ICanvas canvas, RectF dirtyRect)
{
var endAngle = 90 - (int)Math.Round(ArcProgress * 360, MidpointRounding.AwayFromZero);
canvas.StrokeColor = ArcColor;
canvas.StrokeSize = Stroke;
canvas.DrawArc(Stroke / 2, Stroke / 2, (dirtyRect.Width - Stroke), (dirtyRect.Height - Stroke), 90, endAngle, false, false);
}
}
As I am using the MVVM toolkit, I created ObservableProperties in my viewmodel like so:
[ObservableProperty]
double arcProgress;
In my view I integrate the drawable with the data bindings:
<ContentPage.Resources>
<drawables:ProgressArcDrawable
x:Key="progressArcDrawable"
ArcProgress="{Binding ArcProgress}"
Stroke="20"
ArcColor="{Binding Scrum.ScrumTheme.AccentColor}" />
</ContentPage.Resources>
...
<Grid>
<GraphicsView
Drawable="{StaticResource progressArcDrawable}"
HeightRequest="350"
WidthRequest="350" />
</Grid>
The only binding that works, is the one that sets the stroke as a discrete value. The AccentColor binding works on other elements on the page, so there is data in there, but it does not work for the drawable. And thats the same for the ArcProgress, which should change the progress arc once a second.

Try this instead using the Drawable with a StaticResource:
<Grid>
<GraphicsView
HeightRequest="350"
WidthRequest="350">
<GraphicsView.Drawable>
<drawables:ProgressArcDrawable
ArcProgress="{Binding ArcProgress}"
Stroke="20"
ArcColor="{Binding Scrum.ScrumTheme.AccentColor}" />
</GraphicsView.Drawable>
</GraphicsView>
</Grid>

Related

How to implement a WrapPanel with a header and footer

I am trying to implement a custom control that acts similarly to a standard WrapPanel, but that allows you to specify a header and footer. Visually, this is what I am trying to accomplish:
I have created a custom control that seems to leave room for the header and footer items, but I am unable to get them to visually appear. This is my first attempt at any sort of custom control, so any help or input is appreciated!
C#
using System;
using System.Windows;
using System.Windows.Controls;
namespace MyProject.Extras
{
public class HeaderedFooteredPanel : Panel
{
public FrameworkElement Header
{
get { return (FrameworkElement) GetValue(HeaderProperty); }
set { SetValue(HeaderProperty, value); }
}
public FrameworkElement Footer
{
get { return (FrameworkElement)GetValue(FooterProperty); }
set { SetValue(FooterProperty, value); }
}
public static DependencyProperty HeaderProperty = DependencyProperty.Register(
nameof(Header),
typeof(FrameworkElement),
typeof(HeaderedFooteredPanel),
new PropertyMetadata((object)null));
public static DependencyProperty FooterProperty = DependencyProperty.Register(
nameof(Footer),
typeof(FrameworkElement),
typeof(HeaderedFooteredPanel),
new PropertyMetadata((object)null));
protected override Size MeasureOverride(Size constraint)
{
double x = 0.0;
double y = 0.0;
double largestY = 0.0;
double largestX = 0.0;
var measure = new Action<FrameworkElement>(element =>
{
element.Measure(constraint);
if (x > 0 && // Not the first item on this row
(x + element.DesiredSize.Width > constraint.Width) && // We are too wide to fit on this row
((largestY + element.DesiredSize.Height) <= MaxHeight)) // We have enough room for this on the next row
{
y = largestY;
x = element.DesiredSize.Width;
}
else
{
/* 1) Always place the first item on a row even if width doesn't allow it
* otherwise:
* 2) Keep placing on this row until we reach our width constraint
* otherwise:
* 3) Keep placing on this row if the max height is reached */
x += element.DesiredSize.Width;
}
largestY = Math.Max(largestY, y + element.DesiredSize.Height);
largestX = Math.Max(largestX, x);
});
measure(Header);
foreach (FrameworkElement child in InternalChildren)
{
measure(child);
}
measure(Footer);
return new Size(largestX, largestY);
}
protected override Size ArrangeOverride(Size finalSize)
{
double x = 0.0;
double y = 0.0;
double largestY = 0.0;
double largestX = 0.0;
var arrange = new Action<FrameworkElement>(element =>
{
if (x > 0 && // Not the first item on this row
(x + element.DesiredSize.Width > finalSize.Width) && // We are too wide to fit on this row
((largestY + element.DesiredSize.Height) <= MaxHeight)) // We have enough room for this on the next row
{
y = largestY;
element.Arrange(new Rect(new Point(0.0, y), element.DesiredSize));
x = element.DesiredSize.Width;
}
else
{
/* 1) Always place the first item on a row even if width doesn't allow it
* otherwise:
* 2) Keep placing on this row until we reach our width constraint
* otherwise:
* 3) Keep placing on this row if the max height is reached */
element.Arrange(new Rect(new Point(x, y), element.DesiredSize));
x += element.DesiredSize.Width;
}
largestY = Math.Max(largestY, y + element.DesiredSize.Height);
largestX = Math.Max(largestX, x);
});
arrange(Header);
foreach (FrameworkElement child in InternalChildren)
{
arrange(child);
}
arrange(Footer);
return new Size(largestX, largestY);
}
}
}
Usage in XAML:
<ItemsControl ItemsSource="{Binding SomeItems}" ItemTemplate="{StaticResource SomeTemplate}">
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<extras:HeaderedFooteredPanel>
<extras:HeaderedFooteredPanel.Header>
<TextBlock Text="Header" />
</extras:HeaderedFooteredPanel.Header>
<extras:HeaderedFooteredPanel.Footer>
<TextBlock Text="Footer" />
</extras:HeaderedFooteredPanel.Footer>
</extras:HeaderedFooteredPanel>
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
</ItemsControl>
You write in the comments:
The DrawingContext supplied to the OnRender() method only seems to support very basic rendering commands. Surely you don't have to re-write the rendering code for a standard WPF control, but I am not seeing a way to draw them on my own
If by "basic" you mean you are restricted to only DrawingContext operations, then yes. That's exactly what it's for. That's actually the drawing API for WPF. At a higher level, you are dealing with visuals and framework elements, which hide the actual drawing activity. But to override the way such objects are drawn, will require diving down into that level of drawing, replacing it or supplementing it as necessary.
One significant difficulty that would probably arise (besides the more fundamental difficulty of dealing with drawing at that level) is that at that level, there is no such thing as data templates, and no way to access the rendering behaviors of other elements. You have to draw everything from scratch. This would wind up negating a big part of what makes WPF so useful: convenient and powerful control over the exact on-screen representation of data through the use of built-in controls and the properties that give you control over their appearance.
I have only rarely found that a custom Control sub-class is really needed. The only time this comes up is when you need to have complete control over the entire rendering process, to draw something that is simply not possible any other way, or to provide the required performance (at the expense of convenience). Much more often, nearly all of the time even, what you want to do is leverage the existing controls and get them to do all the heavy lifting for you.
In this particular case, I think the key to solving your problem is a type called CompositeCollection. Just like it sounds, it allows you build up a collection as a composite of other objects, including other collections. With this, you can combine your header and footer data into a single collection that can be displayed by an ItemsControl.
In some cases, just creating that collection and using it directly with an ItemsControl object might be sufficient for your needs. But if you want a whole, reusable user-defined control that understands the idea of a header and footer, you can wrap the ItemsControl in a UserControl object that exposes the properties you need, including a Header and Footer property. Here is an example of what that might look like:
XAML:
<UserControl x:Class="TestSO43008469HeaderFooterWrapPanel.HeaderFooterWrapPanel"
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:local="clr-namespace:TestSO43008469HeaderFooterWrapPanel"
mc:Ignorable="d"
d:DesignHeight="300" d:DesignWidth="300">
<ItemsControl x:Name="wrapPanel1">
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<WrapPanel IsItemsHost="True"/>
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
</ItemsControl>
</UserControl>
C#:
public partial class HeaderFooterWrapPanel : UserControl
{
private const int _kheaderIndex = 0;
private const int _kfooterIndex = 2;
private readonly CompositeCollection _composedCollection = new CompositeCollection();
private readonly CollectionContainer _container = new CollectionContainer();
public static readonly DependencyProperty HeaderProperty = DependencyProperty.Register(
"Header", typeof(string), typeof(HeaderFooterWrapPanel),
new PropertyMetadata((o, e) => _OnHeaderFooterPropertyChanged(o, e, _kheaderIndex)));
public static readonly DependencyProperty FooterProperty = DependencyProperty.Register(
"Footer", typeof(string), typeof(HeaderFooterWrapPanel),
new PropertyMetadata((o, e) => _OnHeaderFooterPropertyChanged(o, e, _kfooterIndex)));
public static readonly DependencyProperty ItemsSourceProperty = DependencyProperty.Register(
"ItemsSource", typeof(IEnumerable), typeof(HeaderFooterWrapPanel),
new PropertyMetadata(_OnItemsSourceChanged));
private static void _OnHeaderFooterPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e, int index)
{
HeaderFooterWrapPanel panel = (HeaderFooterWrapPanel)d;
panel._composedCollection[index] = e.NewValue;
}
private static void _OnItemsSourceChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
HeaderFooterWrapPanel panel = (HeaderFooterWrapPanel)d;
panel._container.Collection = panel.ItemsSource;
}
public string Header
{
get { return (string)GetValue(HeaderProperty); }
set { SetValue(HeaderProperty, value); }
}
public string Footer
{
get { return (string)GetValue(FooterProperty); }
set { SetValue(FooterProperty, value); }
}
public IEnumerable ItemsSource
{
get { return (IEnumerable)GetValue(ItemsSourceProperty); }
set { SetValue(ItemsSourceProperty, value); }
}
public HeaderFooterWrapPanel()
{
InitializeComponent();
_container.Collection = ItemsSource;
_composedCollection.Add(Header);
_composedCollection.Add(_container);
_composedCollection.Add(Footer);
wrapPanel1.ItemsSource = _composedCollection;
}
}
Noting, of course, that doing it that way, you would need to "forward" all of the various control properties that you want to be able to set, from the UserControl object to the ItemsPanel. Some, like Background, you can probably just set on the UserControl and have the desired effect, but others are specifically applicable to the ItemsControl, like ItemTemplate, ItemTemplateSelector, etc. You'll have to figure out which those are, and bind the properties, with the source being the UserControl and the target the ItemsControl inside, declaring as dependency properties in your UserControl class any that aren't already part of the UserControl type.
Here's a little sample program that shows how the above could be used:
XAML:
<Window x:Class="TestSO43008469HeaderFooterWrapPanel.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:l="clr-namespace:TestSO43008469HeaderFooterWrapPanel"
xmlns:s="clr-namespace:System;assembly=mscorlib"
DataContext="{Binding RelativeSource={x:Static RelativeSource.Self}}"
mc:Ignorable="d"
Title="MainWindow" Height="350" Width="525">
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition Height="Auto"/>
<RowDefinition Height="Auto"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<StackPanel Orientation="Horizontal" Grid.Row="0">
<TextBlock Text="Header: "/>
<TextBox Text="{Binding Header, ElementName=headerFooterWrapPanel1, UpdateSourceTrigger=PropertyChanged}"/>
</StackPanel>
<StackPanel Orientation="Horizontal" Grid.Row="1">
<TextBlock Text="Footer: "/>
<TextBox Text="{Binding Footer, ElementName=headerFooterWrapPanel1, UpdateSourceTrigger=PropertyChanged}"/>
</StackPanel>
<Button Content="Random List Change" Click="Button_Click" HorizontalAlignment="Left" Grid.Row="2"/>
<l:HeaderFooterWrapPanel x:Name="headerFooterWrapPanel1" ItemsSource="{Binding Items}"
Header="Header Item" Footer="Footer Item" Grid.Row="3">
<l:HeaderFooterWrapPanel.Resources>
<DataTemplate DataType="{x:Type s:String}">
<Border BorderBrush="Black" BorderThickness="1">
<TextBlock Text="{Binding}" FontSize="16"/>
</Border>
</DataTemplate>
</l:HeaderFooterWrapPanel.Resources>
</l:HeaderFooterWrapPanel>
</Grid>
</Window>
For the purpose of illustration, I've set the Window.DataContext property to the Window object itself. This isn't normally a good idea — it's better to have a proper view model to use as the data context — but for a simple program like this, it's fine. Similarly, the Header and Footer properties would normally be bound to some view model property instead of just tying one framework element's property to another.
C#:
public partial class MainWindow : Window
{
public ObservableCollection<string> Items { get; } = new ObservableCollection<string>();
public MainWindow()
{
InitializeComponent();
Items.Add("Item #1");
Items.Add("Item #2");
Items.Add("Item #3");
}
private static readonly Random _random = new Random();
private void Button_Click(object sender, RoutedEventArgs e)
{
switch (Items.Count > 0 ? _random.Next(2) : 0)
{
case 0: // add
Items.Insert(_random.Next(Items.Count + 1), $"Item #{_random.Next()}");
break;
case 1: // remove
Items.RemoveAt(_random.Next(Items.Count));
break;
}
}
}

Windows Phone 7 - ScrollViewer value changed

I am searching all the time for solution and cant get correct one.
I have grid that have width 960 and have ScrollViewer in it. Now i would like to know value (horizontal offset) of my scroll while scrolling. All solutions that i am finding is for wpf/silverlight and it wont works for me.
Edit
Ok, here is the example code, xaml:
<ScrollViewer Name="Scroll" LayoutUpdated="ScrollViewer_LayoutUpdated" IsEnabled="True" Width="480" ScrollViewer.HorizontalScrollBarVisibility="Auto">
<Grid x:Name="ContentPanel" Background="Red" Margin="12,0,12,0" Width="960">
<Rectangle Name="GreenRectangle" Fill="Green" Width="240" Height="240"></Rectangle>
</Grid>
</ScrollViewer>
c#
private void ScrollViewer_LayoutUpdated(object sender, EventArgs e)
{
GreenRectangle.Width = Scroll.HorizontalOffset;
GreenRectangle.Height = Scroll.HorizontalOffset;
}
But the problem is that it is not changing size all the time. Maybe my English is not well and you cant uderstand me. Here is movie example, i am sliding left right and the size is always the same. When i stop sliding it is changing size.
https://www.dropbox.com/s/eh28oavxpsy19bw/20130122_1601_56.avi
It is possible by using the scrollviewers dependency properties, it has a HorizontalOffset and a VerticalOffset. The trick is to bind event to the scrollviewer, but it can bee done in the load event handler. If you put a wide grid in your scrollviewer you can get the offset!
In your xaml file (MainPage sample here):
<ScrollViewer Loaded="ScrollViewer_Loaded_1">
<Grid x:Name="ContentPanel" Grid.Row="1" Width="1000" Margin="12,0,12,0">
<StackPanel>
...
In your code behind file (MainPage.cs here):
public static readonly DependencyProperty ScrollViewVerticalOffsetProperty =
DependencyProperty.Register(
"ScrollViewVerticalOffset",
typeof(double),
typeof(MainPage),
new PropertyMetadata(new PropertyChangedCallback(OnScrollViewVerticalOffsetChanged))
);
public static readonly DependencyProperty ScrollViewHorizontalOffsetProperty =
DependencyProperty.Register(
"ScrollViewHorizontalOffset",
typeof(double),
typeof(MainPage),
new PropertyMetadata(new PropertyChangedCallback(OnScollViewHorizontalOffsetChanged))
);
private ScrollViewer _listScrollViewer;
private void ScrollViewer_Loaded_1(object sender, RoutedEventArgs e)
{
_listScrollViewer = sender as ScrollViewer;
Binding binding1 = new Binding();
binding1.Source = _listScrollViewer;
binding1.Path = new PropertyPath("VerticalOffset");
binding1.Mode = BindingMode.OneWay;
this.SetBinding(ScrollViewVerticalOffsetProperty, binding1);
Binding binding2 = new Binding();
binding2.Source = _listScrollViewer;
binding2.Path = new PropertyPath("HorizontalOffset");
binding2.Mode = BindingMode.OneWay;
this.SetBinding(ScrollViewHorizontalOffsetProperty, binding2);
}
public double ScrollViewVerticalOffset
{
get { return (double)this.GetValue(ScrollViewVerticalOffsetProperty); }
set { this.SetValue(ScrollViewVerticalOffsetProperty, value); }
}
public double ScrollViewHorizontalOffset
{
get { return (double)this.GetValue(ScrollViewHorizontalOffsetProperty); }
set { this.SetValue(ScrollViewHorizontalOffsetProperty, value); }
}
private static void OnScrollViewVerticalOffsetChanged(DependencyObject obj, DependencyPropertyChangedEventArgs e)
{
MainPage page = obj as MainPage;
ScrollViewer viewer = page._listScrollViewer;
// ... do something here
}
private static void OnScollViewHorizontalOffsetChanged(DependencyObject obj, DependencyPropertyChangedEventArgs e)
{
MainPage page = obj as MainPage;
ScrollViewer viewer = page._listScrollViewer;
// ... do something here
}
here's the XAML code I used
<Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,0" LayoutUpdated='ContentPanel_LayoutUpdated'>
<ScrollViewer x:Name='scroller' VerticalAlignment='Stretch' VerticalScrollBarVisibility='Visible' >
<StackPanel
x:Name='listItems'></StackPanel>
</ScrollViewer>
</Grid>
and here's the C# code behind
private void ContentPanel_LayoutUpdated(object sender, EventArgs e)
{
var offset = scroller.VerticalOffset;
}
whenever the scroller is scrolled then the layout of the Grid (Container grid) changes so layout updated event is fired ... please try debugging by placing break point inside the event and look for the offset value ..
Add the property ManipulationMode="Control" to your ScrollViewer. This is needed because otherwise the UI thread will not be notified with enough ScrollViewer scroll values to get a fluid animation – the normal mode is a performance optimization from Windows Phone that you need to bypass!

C#/WPF - Adding a CornerRadius to a ToggleButton

I want create a ToggleButton with round corners by using my CornerRadius property. As you can see in the code below, i already added a cornerRadius property to my xaml ToggleButton to pass a radius value. But i can't find a way to use this value in c# to create a ToggleButton with round corners.
C#
public static readonly DependencyProperty CornerRadiusProperty =
DependencyProperty.Register("CornerRadius", typeof(int), typeof(MyToggleButton),
new PropertyMetadata(0)); //Default CornerRadius = 0
public int CornerRadius
{
get { return (int)GetValue(CornerRadiusProperty); }
set { SetValue(CornerRadiusProperty, value); }
}
XAML
<custom:MyToggleButton Height="25" Content="Test" CornerRadius="15" />
So how can i create a toggleButton with round corners by using my property "CornerRadius"?
Would be great if someone could help me.
I wouldn't create a new control just in order to make it round - that's what templates are for and that's what makes WPF so great! You could simply define a new template for the ToggleButton.
If you insist on inheriting your own control, you'll need to define for it a new default style that will also include a control template that will have a border that uses your CornerRadius property. You can base your new template on the default control template for ToggleButton.

Silverlight TargetNullValue binding for Brush dependency property

I have a reusable user control with a dependency property which sets the color of a rectangle. The property uses Brush as type.
The data binding works fine, however I would like to add a fallback and null value when the binding has errors or its value is not specified.
Here is my XAML:
<Rectangle Fill="{Binding Path=UnderLineColor, ElementName=Header,
FallbackValue=LightGrey, TargetNullValue=LightGrey}"
Height="2"
Margin="0,2"
Grid.Row="1"
Grid.ColumnSpan="2" />
And the code of the UnderLineColor DP:
public Brush UnderLineColor
{
get { return (Brush)GetValue(UnderLineColorProperty); }
set { SetValue(UnderLineColorProperty, value); }
}
public static readonly DependencyProperty UnderLineColorProperty =
DependencyProperty.Register("UnderLineColor", typeof(Brush), typeof(SectionHeader), null);
The issue is that SL doesn't seem to accept the fallback and nullvalue I specify.
What value should I write into these properties to make it work? Or should I use a ValueConverter instead of this approach?
Edit:
Top tip for today: Grey != Gray. Issue is fixed now. :)

Storyboards with bound properties (custom control: animate colour change)

To put it simply, I have this within a ControlTemplate.Triggers condition EnterAction:
<ColorAnimation To="#fe7" Storyboard.TargetProperty="Background.Color" Duration="00:00:00.1" Storyboard.TargetName="brd"/>
But I want the 'to' colour (#fe7) to be customisable. This is a control derived from ListBox. I can create a DependencyProperty, but of course, I cannot bind the To property of the ColorAnimation to it because the Storyboard has to be frozen and you can't freeze something with bindings (as I understand it).
I tried using a {StaticResource} within the To, then populating the resource in the code-behind when the DependencyProperty was changed, by setting this.Resources["ItemColour"] = newValue; for instance. That didn't work perhaps obviously, it's a static resource after all: no new property values were picked up. DynamicResource gave the same problem relating to inability to freeze.
The property is only set once when the control is created, I don't have to worry about it changing mid-animation.
Is there a nice way of doing this? Do I have to resort to looking for property changes myself, dynamically invoking and managing storyboards at that point? Or overlaying two versions of the control, start and end colour, and animating Opacity instead? Both seem ludicrous..
Kieren,
Will this serve your purpose?
I have extended the Grid class called CustomGrid and created a TestProperty whose value when changed will change the background color of Grid:
public class CustomGrid : Grid
{
public bool Test
{
get
{
return (bool)GetValue(TestProperty);
}
set
{
SetValue(TestProperty, value);
}
}
public static readonly DependencyProperty TestProperty =
DependencyProperty.Register("Test", typeof(bool), typeof(CustomGrid),
new PropertyMetadata(new PropertyChangedCallback
((obj, propChanged) =>
{
CustomGrid control = obj as CustomGrid;
if (control != null)
{
Storyboard sb = new Storyboard() { Duration = new Duration(TimeSpan.FromMilliseconds(500)) };
Random rand = new Random();
Color col = new Color()
{
A = 100,
R = (byte)(rand.Next() % 255),
G = (byte)(rand.Next() % 255),
B = (byte)(rand.Next() % 255)
};
ColorAnimation colAnim = new ColorAnimation();
colAnim.To = col;
colAnim.Duration = new Duration(TimeSpan.FromMilliseconds(500));
sb.Children.Add(colAnim);
Storyboard.SetTarget(colAnim, control);
Storyboard.SetTargetProperty(colAnim, new PropertyPath("(Panel.Background).(SolidColorBrush.Color)"));
sb.Begin();
}
}
)));
}
This is the button click event that changes the color:
private void btnClick_Click(object sender, RoutedEventArgs e)
{
gridCustom.Test = (gridCustom.Test == true) ? false : true;
}
I am changing the background color of Grid because I don't have your Listbox.
Finally this is the xaml:
<Grid x:Name="grid" Background="White">
<local:CustomGrid x:Name="gridCustom" Background="Pink" Height="100" Margin="104,109,112,102" >
</local:CustomGrid>
<Button Content="Click Me" x:Name="btnClick" Height="45" HorizontalAlignment="Left" Margin="104,12,0,0" VerticalAlignment="Top" Width="145" Click="btnClick_Click" />
</Grid>
Will this serve your purpose? Let me know or I misunderstood the question?
EDIT:
See this code:
ColorAnimation's To property cannot be bound as you probably guessed. But that doesn't mean you can't change it's value. You can always get a reference to the ColorAnimation and change it's To value and it will all work out well. So from WPF world of binding we need to change a bit and bind the data how we used to do it in Winforms :). As an example see this:
This is the xaml:
<Window
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:Microsoft_Windows_Themes="clr-namespace:Microsoft.Windows.Themes;assembly=PresentationFramework.Aero" x:Class="ControlTemplateTriggers.MainWindow"
Title="MainWindow" Height="350" Width="525">
<Window.Resources>
<Storyboard x:Key="Storyboard">
<ColorAnimation From="Black" To="Red" Duration="00:00:00.500" Storyboard.TargetProperty="(Panel.Background).(SolidColorBrush.Color)" Storyboard.TargetName="gridCustom" />
</Storyboard>
</Window.Resources>
<Grid x:Name="grid" Background="White">
<Grid x:Name="gridCustom" Background="Pink" Height="100" Margin="104,109,112,102" />
<Button Content="Click Me" x:Name="btnClick" Height="45" HorizontalAlignment="Left" Margin="104,12,0,0" VerticalAlignment="Top" Width="145" Click="btnClick_Click" />
</Grid>
</Window>
This is the code behind:
using System.Windows;
using System.Windows.Media.Animation;
using System.Windows.Media;
using System;
namespace Sample {
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
this.DataContext = this;
}
private void btnClick_Click(object sender, RoutedEventArgs e)
{
Storyboard sb = this.Resources["Storyboard"] as Storyboard;
if (sb != null)
{
ColorAnimation frame = sb.Children[0] as ColorAnimation;
Random rand = new Random();
Color col = new Color()
{
A = 100,
R = (byte)(rand.Next() % 255),
G = (byte)(rand.Next() % 255),
B = (byte)(rand.Next() % 255)
};
frame.To = col;
sb.Begin();
}
}
}
}
As you can see I am getting a reference to the storyboard and changing it's To property. Your approach to StaticResource obviously wouldn't work. Now what you can do is, in your DependencyProperty callback somehow get a reference to the Timeline that you want to animate and using VisualTreeHelper or something and then set it's To property.
This is your best bet.
Let me know if this solved your issue :)
can u put multiple DataTriggers with each having respective color for the "To" property...
Surely not..
What i understood is that u want color A on the Condition A and Color B on some other condition B....so if there's a property with multiple options u can put datatriggers for those condition only...like if Job done = Red, Half done = Green like wise..
If i misunderstood the problem please correct me..
I think i got ur question ...UR control is user configurable so what ever user select , control's background needs to be set to that color with animation right?
It turns out this is simply not possible.

Categories

Resources