Develop Reference

C# Wpf drawing with Combobox

I need help with drawing in my combobox. I want to make a combobox of colors for picking. I found some stuff on the internet but none of them is working. So far I have this :
private void MyComb_DrawItem(object sender, DrawItemEventArgs e)
{
Graphics g = e.Graphics;
System.Drawing.Rectangle rect = e.Bounds;
ColorConverter converter = new ColorConverter();
if (e.Index >= 0)
{
string n = ((ComboBox)sender).Items[e.Index].ToString();
System.Drawing.Color c = (System.Drawing.Color)converter.ConvertFromString(n);
SolidBrush b = new SolidBrush(c);
g.FillRectangle(b, rect.X + 110, rect.Y + 5,
rect.Width - 10, rect.Height - 10);
}
}
This is my drawItem method
<Grid>
<ComboBox x:Name="MyComb" HorizontalAlignment="Left" Margin="66,81,0,0" VerticalAlignment="Top" Width="120" />
</Grid>
This is definition of combobox
Type colorType = typeof(System.Drawing.Color);
PropertyInfo[] propInfoList = colorType.GetProperties(BindingFlags.Static |
BindingFlags.DeclaredOnly | BindingFlags.Public);
foreach (PropertyInfo c in propInfoList)
{
MyComb.Items.Add(c.Name);
}
And here I am filling combobox with colors names and then I want to fill to combox with real colors according to the colors names.. But my draw item method is never called. I tried to create some DrawItem handler but, my combobox have no such thing... Then I read something about setting a DrawMode property of combobox, but my combobox doesn't that kind of property at all...
I am using net framework v.4.6.1
Can please anyone tell me, what am I missing ?
Thank you very much

The biggest problem you're having is that you're trying to use code examples that were written for the Winforms API, even though you are using the WPF API. For future reference, you really need to be more careful about identifying the context of tutorials and other resources you find online, to make sure they actually apply to your scenario.
As it happens, we have a number of related questions on Stack Overflow already:
WPF ComboBox as System.Windows.Media.Colors>
WPF - Bind ComboBox Item Foreground to Its Value
Very simple color picker made of combobox
These are all potentially useful to you, but are all based on the answer to this question:
How can I list colors in WPF with XAML?
Which was originally about just displaying the names of colors, and so took a short-cut, using the <ObjectDataProvider/> element in XAML. This led to the need to use a converter in the other questions, to convert either from a string value or a PropertyInfo instance to the appropriate color or brush.
In fact, if your code is already written to use some type of MVVM approach, and especially since you've already written code-behind to retrieve the color values from the Colors type, or at least tried to (one of the problems in your code is that you are using the Winforms Color type instead of the WPF Colors type…again, in Winforms that works fine, but the WPF API follows the Code Analysis/FxCop rules more closely, and the named colors are in the Colors type), it makes sense to just stick with that and provide a direct view model data structure to which you can bind.
In this approach, rather than providing a procedural implementation of the item drawing, you provide in XAML a declarative implementation describing what each item should look like.
Here is an example…
First, some simple view model data structures:
// Very simple container class
class ColorViewModel
{
public Brush Brush { get; }
public string Name { get; }
public ColorViewModel(Brush brush, string name)
{
Brush = brush;
Name = name;
}
}
// Main view model, acts as the data context for the window
class MainViewModel : INotifyPropertyChanged
{
public IReadOnlyList<ColorViewModel> Colors { get; }
private Brush _selectedColor;
public Brush SelectedColor
{
get { return _selectedColor; }
set { _UpdateField(ref _selectedColor, value); }
}
public MainViewModel()
{
Colors = typeof(Colors).GetProperties(BindingFlags.Static | BindingFlags.Public)
.Select(p => new ColorViewModel(new SolidColorBrush((Color)p.GetValue(null)), p.Name))
.ToList().AsReadOnly();
}
public event PropertyChangedEventHandler PropertyChanged;
private void _UpdateField<T>(ref T field, T newValue, [CallerMemberName] string propertyName = null)
{
if (!EqualityComparer<T>.Default.Equals(field, newValue))
{
field = newValue;
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
}
}
With those in hand, the XAML is straight-forward:
<Window x:Class="TestSO47850587ColorComboBox.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:TestSO47850587ColorComboBox"
mc:Ignorable="d"
Title="MainWindow" Height="350" Width="525">
<Window.DataContext>
<l:MainViewModel/>
</Window.DataContext>
<StackPanel>
<ComboBox Width="100" ItemsSource="{Binding Colors}"
HorizontalAlignment="Left" Grid.IsSharedSizeScope="True"
SelectedValuePath="Brush" SelectedValue="{Binding SelectedColor}">
<ComboBox.ItemTemplate>
<DataTemplate DataType="{x:Type l:ColorViewModel}">
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto" SharedSizeGroup="ComboBoxItem"/>
</Grid.ColumnDefinitions>
<TextBlock Text="{Binding Name}" Background="{Binding Brush}" HorizontalAlignment="Stretch"/>
</Grid>
</DataTemplate>
</ComboBox.ItemTemplate>
</ComboBox>
<Rectangle HorizontalAlignment="Stretch" Height="24" Fill="{Binding SelectedColor}"/>
</StackPanel>
</Window>
The above displays the color names, using the actual color as the background. If all you really want is a rectangle, then you can replace the <TextBlock/> element with a <Rectangle/> element, binding to its Fill property. Naturally, you can achieve other visual effects, such as a rectangle with a margin. It's just a matter of configuring your data template according to your need.
The main point here is that you should embrace the data binding approach that defines good WPF programming, and that you should definitely not mistake Winforms code examples for WPF. :)

Dynamic UI Layout in DataGridCell using ItemsControl and a Button

This screenshot is from the mockup of my ideal UI. Right now, this is a DataGridTemplateColumn, with header = "ATTENDEES". I am running into issues creating the layout of this DataGridColumn's cell.
I currently have an ItemsControl bound to a List of strings which are the attendees' emails. If there are too many attendees and the ItemsControls' bounds cannot fit in the cell, then a Button with Content = "See more" should appear at the bottom of the cell, under the last attendee email that can be rendered within in the cell's bounds.
Then once the Button ("See more") is clicked, the row should expand to an appropriate height for the attendees to all be visible, and the "See more" Button should disappear.
I could not wrap my head around a clean implementation with a TemplateSelector, ValueConverter, or DataTrigger in pure XAML since I need to compare the ItemsControls' height against the DataGridRow's height and then perform a modification of the cell's layout at runtime by hiding all the items in the ItemsControl that cannot fit within the cell and then showing at Button below it.
I concluded on attempting to do this in the code-behind by subscribing to the ItemControls' load event. I first attempted to use the Height, MaxHeight, DesiredSize.Height, RenderedSize.Height, and ActualSize.Height properties of the ItemsControl but those all were equal to the clipped height of the ItemsControl, not the intrinsic height of all its contents.
I am now measuring the total height of all its items' strings using the FormattedText class. Then I compare this summed height with the row's height and that's as far as I have progressed; I am unsure of how to next change the layout of the cell or if this is even the correct approach.
I feel like I am fighting against the design of the WPF framework by doing rudimentary calculations and crude layout changes to the view in the code-behind.
Any help on this would be greatly appreciated!
Here is my event handler for the ItemsControl.Load:
private void AttendeesItemsControl_Loaded(object sender, RoutedEventArgs e)
{
if (currentRowIndex == -1)
{
return;
}
List<ModelBase> eventsData = ModelManager.events.data;
var eventObj = (Event)eventsData[currentRowIndex];
var attendees = eventObj.attendees;
var totalItemsHeight = 0;
for(int i = 0; i < attendees.Count; i++)
{
totalItemsHeight += heightOfString(attendees[i]);
}
var itemsControl = (ItemsControl)sender;
var controlRenderHeight = itemsControl.RenderSize.Height;
// Check if the intrinsic height is greater than what can be drawn inside the cell
if (controlRenderHeight < totalItemsHeight)
{
var itemHeight = totalItemsHeight / attendees.Count;
var visibleItemsCount = controlRenderHeight / itemHeight;
// .... not sure how to proceed
}
}
And the helper function that measures the height of one of its items:
private int heightOfString(string candidate)
{
var fontFamily = new FontFamily("Lato");
var fontStyle = FontStyles.Normal;
var fontWeight = FontWeights.Normal;
var fontStretch = FontStretches.Normal;
var fontSize = 12;
var typeFace = new Typeface(fontFamily, fontStyle, fontWeight, fontStretch);
var formattedText = new FormattedText(candidate, CultureInfo.CurrentUICulture, FlowDirection.LeftToRight, typeFace, fontSize, Brushes.Black);
return (int)formattedText.Height;
}
Finally, this is the DataGridTemplateColumn's XAML, with the cell template definition:
<DataGridTemplateColumn Header="ATTENDEES" Width="*">
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<ItemsControl ItemsSource="{Binding Path=attendees}" x:Name="AttendeesItemsControl" Loaded="AttendeesItemsControl_Loaded">
<ItemsControl.ItemTemplate>
<DataTemplate>
<TextBlock FontFamily="Lato" FontSize="12" FontWeight="Normal" Text="{Binding}">
</TextBlock>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>

I had to do some real work but I got this set up. Hopefully you can follow it. Here is a screen shot of what it looks like. Obviously i didn't attempt to style it yet. Just getting the resizing. This way you let WPF handle the height of your control you leave it autosized. You just manage your list.
I created a control for the list called AttendeeListControl
<UserControl xmlns:stackoverflow="clr-namespace:stackoverflow" x:Class="stackoverflow.AttendeeListControl"
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"
mc:Ignorable="d"
d:DesignHeight="300" d:DesignWidth="300">
<Grid Background="GhostWhite">
<Grid.RowDefinitions>
<RowDefinition Height="37"/>
<RowDefinition Height="*"/>
<RowDefinition Height="23"/>
</Grid.RowDefinitions>
<Label Content="Attendees" HorizontalAlignment="Left" Margin="10,10,0,0" VerticalAlignment="Top"/>
<ListBox Name="listBoxAttendees" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Grid.Row="1" />
<Button Content="SeeMore" Name="lblMore" HorizontalAlignment="Left" Margin="10,0,0,0" Grid.Row="2" VerticalAlignment="Top" Click="lblMore_Click"/>
</Grid>
</UserControl>
This is the code behind
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Windows.Controls;
namespace stackoverflow
{
/// <summary>
/// Interaction logic for AttendeeListControl.xaml
/// </summary>
///
public partial class AttendeeListControl : UserControl
{
public AttendeeListViewModel vm { get; set; }
public AttendeeListControl()
{
InitializeComponent();
var emails = new List<string>() { "email#gmail.com", "email#aol.com", "email.yahoo.com", "email#msn.com" };
var displayed = new ObservableCollection<string>() { emails[0], emails[1] };
vm = new AttendeeListViewModel()
{
EmailList = emails,
DisplayList = displayed,
Expanded = false
};
DataContext = vm;
listBoxAttendees.ItemsSource = vm.DisplayList;
}
private void lblMore_Click(object sender, System.Windows.RoutedEventArgs e)
{
if (vm.Expanded)
{
//remove all but last 2
do
{
vm.DisplayList.RemoveAt(vm.DisplayList.Count - 1);
} while (vm.DisplayList.Count > 2);
lblMore.Content = "Show More";
}
else
{
//don't want the first 2
for (int i = 2; i < vm.EmailList.Count; i++)
{
vm.DisplayList.Add(vm.EmailList[i]);
}
lblMore.Content = "Show Less";
}
vm.Expanded = !vm.Expanded;
}
}
}
and here is the model i used
using System.Collections.Generic;
using System.Collections.ObjectModel;
namespace stackoverflow
{
public class AttendeeListViewModel
{
public bool Expanded { get; set; }
public List<string> EmailList { get; set; }
public ObservableCollection<string> DisplayList { get; set; }
}
}
this was all just put on the mainwindow
<Window
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:stackoverflow" x:Class="stackoverflow.MainWindow"
Title="MainWindow" Height="350" Width="525">
<Grid>
<local:AttendeeListControl HorizontalAlignment="Left" Margin="55,53,0,0" VerticalAlignment="Top"/>
<local:AttendeeListControl HorizontalAlignment="Left" Margin="340,53,0,0" VerticalAlignment="Top"/>
</Grid>
</Window>

How to deal with empty RichTextBox selection [duplicate]

I need to set the font family for the next text to be written in a RichTextBox.
I tried setting that with...
<RichTextBox x:Name="RichTextEditor" MaxWidth="1000" SpellCheck.IsEnabled="True"
FontFamily="{Binding ElementName=TextFontComboBox, Path=SelectedItem}"
FontSize="{Binding ElementName=TextSizeComboBox, Path=SelectedValue}"
Width="Auto" Height="Auto" HorizontalScrollBarVisibility="Auto"
VerticalScrollBarVisibility="Auto" />
...but it changed the whole text. I suppose that with the Selection property I can restrict the change to be applied just to the selected area. But how for the next -not yet typed- text?

In order to set the FontFamily based on the cursor position you need to define a custom control with a dependency property that helps insert a new Run section by overriding the OnTextInput method.
I included most of the code, you'll need to modify the namespaces to fit your development environment.
The code uses a ViewModel to manage the available fonts and manage if the font changed.
This code is only a prototype and does not deal with focusing issues between the two controls.
To use this code:
1- Type some text in the RichTectBox.
2- Change the font in the ComboBox.
3- Tab back to the RichTextBox.
4- Type some more text.
Here is the custom RichTextBox control:
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
namespace RichTextboxFont.Views
{
public class RichTextBoxCustom : RichTextBox
{
public static readonly DependencyProperty CurrentFontFamilyProperty =
DependencyProperty.Register("CurrentFontFamily",
typeof(FontFamily), typeof
(RichTextBoxCustom),
new FrameworkPropertyMetadata(new FontFamily("Tahoma"),
FrameworkPropertyMetadataOptions.BindsTwoWayByDefault,
new PropertyChangedCallback(OnCurrentFontChanged)));
public FontFamily CurrentFontFamily
{
get
{
return (FontFamily)GetValue(CurrentFontFamilyProperty);
}
set
{
SetValue(CurrentFontFamilyProperty, value);
}
}
private static void OnCurrentFontChanged(DependencyObject o, DependencyPropertyChangedEventArgs e)
{}
protected override void OnTextInput(TextCompositionEventArgs e)
{
ViewModels.MainViewModel mwvm = this.DataContext as ViewModels.MainViewModel;
if ((mwvm != null) && (mwvm.FontChanged))
{
TextPointer textPointer = this.CaretPosition.GetInsertionPosition(LogicalDirection.Forward);
Run run = new Run(e.Text, textPointer);
run.FontFamily = this.CurrentFontFamily;
this.CaretPosition = run.ElementEnd;
mwvm.FontChanged = false;
}
else
{
base.OnTextInput(e);
}
}
}
}
Here is the XAML:
<Window x:Class="RichTextboxFont.Views.MainView"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:RichTextboxFont.Views"
xmlns:ViewModels="clr-namespace:RichTextboxFont.ViewModels"
Title="Main Window"
Height="400" Width="800">
<DockPanel>
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition/>
</Grid.RowDefinitions>
<ComboBox ItemsSource="{Binding Path=Fonts}"
SelectedItem="{Binding Path=SelectedFont, Mode=TwoWay}"/>
<local:RichTextBoxCustom Grid.Row="1"
CurrentFontFamily="{Binding Path=SelectedFont, Mode=TwoWay}"
FontSize="30"/>
</Grid>
</DockPanel>
</Window>
Here is the ViewModel:
If you do not use view models, let me know and I'll add the base class code too; otherwise, google/stackoverflow can help you too.
using System.Collections.ObjectModel;
using System.Windows.Media;
namespace RichTextboxFont.ViewModels
{
public class MainViewModel : ViewModelBase
{
#region Constructor
public MainViewModel()
{
FontFamily f1 = new FontFamily("Georgia");
_fonts.Add(f1);
FontFamily f2 = new FontFamily("Tahoma");
_fonts.Add(f2);
}
private ObservableCollection<FontFamily> _fonts = new ObservableCollection<FontFamily>();
public ObservableCollection<FontFamily> Fonts
{
get
{
return _fonts;
}
set
{
_fonts = value;
OnPropertyChanged("Fonts");
}
}
private FontFamily _selectedFont = new FontFamily("Tahoma");
public FontFamily SelectedFont
{
get
{
return _selectedFont;
}
set
{
_selectedFont = value;
FontChanged = true;
OnPropertyChanged("SelectedFont");
}
}
private bool _fontChanged = false;
public bool FontChanged
{
get
{
return _fontChanged;
}
set
{
_fontChanged = value;
OnPropertyChanged("FontChanged");
}
}
#endregion
}
}
Here is the Window code-behind where I initialise the ViewModel:
using System.Windows;
namespace RichTextboxFont.Views
{
public partial class MainView : Window
{
public MainView()
{
InitializeComponent();
this.DataContext = new ViewModels.MainViewModel();
}
}
}

There's a much easier way to do this: Implement a toolbar for your RichTextBox.
Unlike WinForms, the RichTextBox in WPF doesn't come with a toolbar by default, but it's really easy to create one yourself. The RichTextBox automatically handles many EditingCommands, so it's just a matter of creating a toolbar and some buttons. Microsoft has provided sample code for this at the bottom of the RichTextBox Overview on MSDN.
Unfortunately, those editing commands don't include setting the FontFace property of the selection, though you can create a ComboBox on the toolbar that can trigger the change with an event handler in the codebehind file.
That's the approach taken in this CodePlex article by Gregor Pross: WPF RichTextEditor
The project is commented in German, but the source itself is very clearly written. The codebehind used for his font selector ComboBox looks like this:
private void Fonttype_DropDownClosed(object sender, EventArgs e)
{
string fontName = (string)Fonttype.SelectedItem;
if (fontName != null)
{
RichTextControl.Selection.ApplyPropertyValue(System.Windows.Controls.RichTextBox.FontFamilyProperty, fontName);
RichTextControl.Focus();
}
}
The main reason that people struggle with the FontFace selection is that after the font selection has been made, you must return focus to the RichTextBox. If the user must manually press tab or click into the RichTextBox, a new text selection gets created and you lose the formatting options you've chosen.
One of the answers to this StackOverflow question discusses that problem.
WPF Richtextbox FontFace/FontSize

This isn't exactly a trivial answer.
To do inline text formatting in a Rich TextBox like you want you will have to modify the Document property of the RichTextBox. Very simply, something like this will work
<RichTextBox >
<RichTextBox.Document>
<FlowDocument>
<Paragraph>
<Run>Something</Run>
<Run FontWeight="Bold">Something Else</Run>
</Paragraph>
</FlowDocument>
</RichTextBox.Document>
</RichTextBox>
I think you could create a custom Control that creates a new block element and sets the font properties you need based on the user input.
For example, If the user types something then presses bold. You would want to wrap the previous text in a run and create a new run element setting the FontWeight to bold then the subsequent text will be wrapped in the bolded run.
Again, not a trivial solution but I can't think of any other way to accomplish what you are after.

To remove focus rectangle in WPFwithin a UserControl

I have a situation where I need to tab using TabKey from one control to another. The condition is that the focus should never go to control that does not have user inputs so only Text, ComboBox, List DatePicker but somehow the focus after 3 controls get the Focus to go to a dashed line Rectangle (Could be of a Grid, StackPanel, I have not been able to findout) around the control groups before it gets into the control. I have searched very thoroughly in Google and stack over flow for a solution but none seem to work.
Various solutions I tried:
1) Here I set FocusVisualStyle property to null right at start up for Grid and StackPanels. Created a new class:
<StackPanel views:FocusVisualTreeChanger.IsChanged="True" Name="parentStackPanel" Orientation="Vertical" Style="{DynamicResource key1}" FocusVisualStyle="{x:Null}">
public class FocusVisualTreeChanger
{
public static bool GetIsChanged(DependencyObject obj)
{
return (bool)obj.GetValue(IsChangedProperty);
}
public static void SetIsChanged(DependencyObject obj, bool value)
{
obj.SetValue(IsChangedProperty, value);
}
public static readonly DependencyProperty IsChangedProperty =
DependencyProperty.RegisterAttached("IsChanged", typeof(bool), typeof(FocusVisualTreeChanger), new FrameworkPropertyMetadata(false, FrameworkPropertyMetadataOptions.Inherits, IsChangedCallback));
private static void IsChangedCallback(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
if (true.Equals(e.NewValue))
{
FrameworkContentElement contentElement = d as FrameworkContentElement;
if (contentElement != null)
{
contentElement.FocusVisualStyle = null;
return;
}
FrameworkElement element = d as FrameworkElement;
if (element != null)
{
element.FocusVisualStyle = null;
}
}
}
}
Did not work.
I tried setting FocusVisualStyle property to null for only Grid and StackPanel seems to go through the codebehind if I put a break point but the focus rectangle does not go away:
<Grid Name="AppointmentGrid" Style="{DynamicResource key2}" FocusVisualStyle="{x:Null}">
Style style = new Style { TargetType = typeof(Grid) };
style.Setters.Add(new Setter(Grid.FocusVisualStyleProperty, null));
style.Setters.Add(new Setter(Grid.FocusableProperty, false));
Application.Current.Resources["key2"] = style;
Application.Current.Resources["key3"] = style;
Application.Current.Resources["key4"] = style;
Style style1 = new Style { TargetType = typeof(StackPanel) };
style1.Setters.Add(new Setter(StackPanel.FocusVisualStyleProperty, null));
style1.Setters.Add(new Setter(StackPanel.FocusableProperty, false));
Application.Current.Resources["key1"] = style1;
Can anyone please help me out with a solution that I have not already tried. None in stackoverflow solutions seem to work. I also set Focusable=false just incase but that doesn't seem to help either.
I also read:
Remove focus rectangle on a UserControl
WPF Control remove focus and hover effect (FocusVisualStyle?!)
WPF: Remove dotted border around focused item in styled listbox
This is what I think I am stuck at. A comment I found in one of the search sites.
That's a great way to change the default value of a DP, but it will not help in situations where a control's style explicitly changes the property value. Unfortunately, FocusVisualStyle is one such property. More specifically, styles for controls like Button, ComboBox, ListBox, etc. tend to explicitly contain a Setter for the FocusVisualStyle property. This setter will override the default value that you establish by overriding the metadata.
Can someone suggest a solution that will work in my case. I have a User control
<UserControl
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:csla="http://schemas.lhotka.net/4.2.0/xaml"
xmlns:input="clr-
FocusVisualStyle="{x:Null}"
Focusable="False"
xmlns:controls="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls.Input.Toolkit"
mc:Ignorable="d" d:DesignWidth="948"
IsTabStop="False"
TabIndex="-1">
<StackPanel views:FocusVisualTreeChanger.IsChanged="True" Name="parentStackPanel" Orientation="Vertical" Style="{DynamicResource key1}" FocusVisualStyle="{x:Null}"><Grid Name="AppointmentGrid" Style="{DynamicResource key2}" FocusVisualStyle="{x:Null}">
Thanks
Dhiren

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!