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DataTrigger for IconTemplate in RadWindow

I have a WPF application and I use Telerik.
I'm trying to set the Icon Template so that it has a default value and only on a certain condition will it bind the image source:
<telerik:RadWindow.Resources>
<Style x:Key="CustomIconStyle" TargetType="Image">
<Style.Triggers>
<DataTrigger Binding="{Binding Path=IsConditionMet, ElementName=MyWindow, UpdateSourceTrigger=PropertyChanged}" Value="True">
<Setter Property="Source" Value="{Binding Path=IconImageSource, ElementName=MyWindow, UpdateSourceTrigger=PropertyChanged}"/>
</DataTrigger>
</Style.Triggers>
</Style>
</telerik:RadWindow.Resources>
<telerik:RadWindow.IconTemplate>
<DataTemplate>
<Image Style="{StaticResource CustomIconStyle}" Source="/MyAssembly;Component/Resources/myIcon.ico" Height="16" Margin="0,0,5,0"/>
</DataTemplate>
</telerik:RadWindow.IconTemplate>
For some reason it always show the default icon.
I would also like to mention that I did implement the property changed - and I copied the same style just to a control inside the window and not in the template and it worked - so the problem isn't with the property changed
Any ideas?

You can use Triggers like that :
<telerik:RadWindow.Resources>
<Style TargetType="Image" x:Key="Style1">
<Setter Property="Source" Value="default.ico"/>
<Style.Triggers>
<DataTrigger Binding="{Binding MyCondition}" Value="true">
<Setter Property="Source" Value="custom.ico"/>
</DataTrigger>
</Style.Triggers>
</Style>
</telerik:RadWindow.Resources>
<telerik:RadWindow.IconTemplate>
<DataTemplate>
<Image Style="{StaticResource Style1}" Height="16" Margin="0,0,5,0"/>
</DataTemplate>
</telerik:RadWindow.IconTemplate>

So the problem was that once the RadWindow was loaded it didn't change the Icon.
The solution:
<telerik:RadWindow.IconTemplate>
<DataTemplate>
<Image Height="16" Margin="0,0,5,0">
<Image.Style>
<Style TargetType="{x:Type Image}">
<Setter Property="Source" Value="/MyAssembly;Component/Resources/myIcon.ico" />
<Style.Triggers>
<DataTrigger Value="True" Binding="{Binding Path=IsConditionMet, ElementName=MyWindow}">
<Setter Property="Source" Value="{Binding Path=IconImageSource, ElementName=MyWindow}"/>
</DataTrigger>
</Style.Triggers>
</Style>
</Image.Style>
</Image>
</DataTemplate>
</telerik:RadWindow.IconTemplate>
But the trick is to give the correct value of IsConditionMet in the windows constructor before the load.
Thanks for the help everyone.

WPF Style Triggers for DataTemplates

I would like to set Triggers for the controls in a DataTemplate. Whenever I set a property of the control within the DataTemplate, it seems not working. However, If do not set the property within the TextBlock inside the DataTemplate, then I can see the effect of Trigger in the style (it works). I am not sure whether using Style Triggers with DataTemplate is good or not! The XAML is below;
<Grid>
<Grid.Resources>
<Style TargetType="TextBlock" x:Key="BlockOf">
<Style.Triggers>
<Trigger Property="IsMouseOver" Value="True">
<Setter Property="FontWeight" Value="ExtraBold" />
<Setter Property="FontSize" Value="22" />
</Trigger>
</Style.Triggers>
</Style>
</Grid.Resources>
...........
DataTemplate for the button,
<Button.ContentTemplate>
<DataTemplate DataType="Button">
<TextBlock Style="{DynamicResource BlockOf}" Text="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=Content}"
FontStyle="Italic" FontSize="9"/>
</DataTemplate>
</Button.ContentTemplate>

I can see two problems here. First one is that current trigger will work only for TextBlock inside Button, not over whole Button. You can change that by using DataTrigger with RelativeSource binding. Second problem is that even when mouse is over TextBlock Style.Trigger cannot overwrite local value that you set against TextBlock so you need to bring default values as Setter into your Style. Check Dependency Property Setting Precedence List
<Style TargetType="TextBlock" x:Key="BlockOf">
<Setter Property="FontStyle" Value="Italic"/>
<Setter Property="FontSize" Value="9"/>
<Style.Triggers>
<DataTrigger Binding="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type Button}}, Path=IsMouseOver}" Value="True">
<Setter Property="FontWeight" Value="ExtraBold" />
<Setter Property="FontSize" Value="22" />
</DataTrigger>
</Style.Triggers>
</Style>
and then TextBlock simply
<TextBlock Style="{DynamicResource BlockOf}" Text="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=Content}" />

How to Bind an another Control on the Setter Value Property by using a Trigger?

i've a little Problem with the Databinding in WPF an hope you can help me.
I want to bind the SelectedDate Parameter of a DatePicker on a TextBlock, but only when a CheckBox is checked. The CheckBox and the TextBlock are in a DataView, the DatePicker is outside.
In the Moment i try to use it with a Trigger an set the Binding in the Value-Property in the Setter Part.
<TextBlock Text="">
<TextBlock.Style>
<Style TargetType="TextBlock">
<Style.Triggers>
<DataTrigger Binding="{Binding Path=IsChecked}" Value="True">
<Setter Property="Text" Value="{Binding ElementName=StandartPitBis, Path=SelectedDate, StringFormat='dd.MM.yyyy'}" />
</DataTrigger>
</Style.Triggers>
</Style>
</TextBlock.Style>
</TextBlock>
But this will not works. Has anywone a Tipp what i can do?
Here is the Code-Parts there i'm using:
Inside the GridView
The CheckBox
<GridViewColumn>
<GridViewColumn.CellTemplate>
<DataTemplate>
<CheckBox Content="" x:Name="check_Anlage" IsChecked="{Binding Path=IsChecked}" />
</DataTemplate>
</GridViewColumn.CellTemplate>
</GridViewColumn>
The TextBlock
<TextBlock Text="">
<TextBlock.Style>
<Style TargetType="TextBlock">
<Style.Triggers>
<DataTrigger Binding="{Binding Path=IsChecked}" Value="True">
<Setter Property="Text" Value="{Binding ElementName=StandartPitBis, Path=SelectedDate, StringFormat='dd.MM.yyyy'}" />
</DataTrigger>
</Style.Triggers>
</Style>
</TextBlock.Style>
</TextBlock>
Outside the GridView
The DatePicker
<DatePicker Grid.Column="1" Margin="0,5,0,5" SelectedDate="{x:Static sys:DateTime.Now}" x:Name="StandartPitVon" />
What i want to make is, that the SelectedDate from the DatePicker is shown in the TextBlock, but only when the CheckBox is Checked.
Thanks a lot

So. I've found the Problem. The Problem is, when a Property is set in the Object self, then it can't be overridet. When you need a Default-Value and a Trigger, then you must define the Default-Value in the Style too.
Example:
<TextBlock>
<TextBlock.Style>
<Style TargetType="TextBlock">
<Setter Property="Text" Value="{x:Null}" />
<Style.Triggers>
<DataTrigger Binding="{Binding Path=IsChecked}" Value="True">
<Setter Property="Text" Value="{Binding ElementName=StandartPitVon, Path=SelectedDate, StringFormat='dd.MM.yyyy'}" />
</DataTrigger>
</Style.Triggers>
</Style>
</TextBlock.Style>
</TextBlock>

DataGridTemplateColumn.HeaderTemplate issue

Please help on this issue and I'm not sure how to handle this.
I've combox box and datagrid. When ever I've selected combox value datagrid should be loaded with new data and that works perfectly. But I've DataGridTemplateColumn.HeaderTemplate with checkbox when I checked all the column with checkbox is also checked and also worked with unchecked as well. Both are fine.
Now my issue is when i selected combobox, datagrid --> headertemplate checkbox should be unchecked. IS there any event I can fire for this? My code below.
Combox is outside the datagrid.
<DataGridTemplateColumn>
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<CheckBox Name="checkadded" Margin="6,0" IsChecked="{Binding IsSelected, NotifyOnSourceUpdated=True, NotifyOnTargetUpdated=True, UpdateSourceTrigger=PropertyChanged}" />
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
<DataGridTemplateColumn.HeaderTemplate>
<DataTemplate>
<CheckBox Name="ChkAllAdd" IsChecked="False" Width="50" Loaded="chkallLoaded" Checked="ChkAll_Checked" Unchecked="ChkAll_Unchecked" IsThreeState="False" Padding="4,3,4,3" HorizontalContentAlignment="Left" HorizontalAlignment="Center" />
</DataTemplate>
</DataGridTemplateColumn.HeaderTemplate>
</DataGridTemplateColumn>
</DataGrid.Columns>
<DataGrid.Resources>
<Style TargetType="{x:Type DataGridColumnHeader}">
<Setter Property="Foreground" Value="#686868"/>
<Setter Property="FontWeight" Value="Bold" />
</Style>
<Style TargetType="{x:Type DataGridCell}" >
<Style.Triggers>
<Trigger Property="IsSelected" Value="True">
<Setter Property="Foreground" Value="white"/>
<Setter Property="Background" Value="#93A8A9"/>
<Setter Property="FontWeight" Value="Bold"/>
</Trigger>
</Style.Triggers>
</Style>
</DataGrid.Resources>
</DataGrid>

Create a ControlTemplate for Content Control and place your DataGrid and ComboBox Xaml in that. Now you can create an EventTrigger for Combobox and there you can set the CheckedBox Checked using element name in binding. This can be helpfull.

Make xaml datatrigger work in c# code

I am new to xaml, i have following code below, my question is how can i call InvalidForeground from c# code to change the color of checkbox text?
<ControlTemplate x:Key="ItemTemplate"
TargetType="ListViewItem">
<StackPanel Orientation="Horizontal">
<CheckBox x:Name="CkBoxVisual">
<CheckBox.IsChecked>
<Binding Path="IsSelected"
Mode="TwoWay">
<Binding.RelativeSource>
<RelativeSource Mode="TemplatedParent" />
</Binding.RelativeSource>
</Binding>
</CheckBox.IsChecked>
<DataTrigger Binding="{Binding InvalidForeground, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type Window}}}" Value="true">
<Setter TargetName="CkBoxVisual" Property="Foreground" Value="Red"/>
</DataTrigger>
</CheckBox>
<ContentPresenter />
</StackPanel>
</ControlTemplate>

In your code, you are not calling anything. In it, you're hoping a change of dependency property..
But a control of type Window does not have a dependency property with the name: "InvalidForeground".
This trigger will never be triggered.
What is your goal, change a property or be notified of a change (trigger)?
Edit: There are a number of rules you must follow:
1) The control referenced in Binding property from DataTrigger (RelativeSource):
Binding="{Binding Path=InvalidForeground, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type Window}}}"
Must have a dependency property called "InvalidForeground", which works correctly, based on this, will not work:
{x:Type Window}
its type must be declared, will work, for example:
{x:Type my:ControlName}
2) A property changed by a Trigger or DataTrigger can never be explicitly stated, for example. Will not work:
<TextBlock Text="{Binding Any}" Foreground="#FFCCCCCC">
<TextBlock.Style>
<Style TargetType="TextBlock">
<Style.Triggers>
<DataTrigger Binding="{Binding RelativeSource={RelativeSource AncestorType=TabItem, Mode=FindAncestor}, Path=IsSelected}" Value="True">
<Setter Property="Foreground" Value="Black"/>
</DataTrigger>
</Style.Triggers>
</Style>
</TextBlock.Style>
</TextBlock>
Will work:
<TextBlock Text="{Binding Any}">
<TextBlock.Style>
<Style TargetType="TextBlock">
<Setter Property="Foreground" Value="#FFCCCCCC"/>
<Style.Triggers>
<DataTrigger Binding="{Binding RelativeSource={RelativeSource AncestorType=TabItem, Mode=FindAncestor}, Path=IsSelected}" Value="True">
<Setter Property="Foreground" Value="Black"/>
</DataTrigger>
</Style.Triggers>
</Style>
</TextBlock.Style>
</TextBlock>
3) Check the operation of Bindings using RelativeSource they have some peculiarities (you should know a little about the visual tree of WPF).
http://msdn.microsoft.com/en-us/library/ms743599.aspx
4) You should check that the binding is working properly and can follow these steps:
http://www.codeproject.com/Articles/244107/Debugging-WPF-data-bindings