When you define a arbitrary Control in Resources
, you can use it in the future in Control which have property Content
and derived from Control
class. These are the followings: ContentControl
, Label
, ContentPresenter
, etc.
Also you must set x:Shared="False"
for resource if you want to use this resource in many Controls, because x:Shared="True"
by default then one Resource is common to all - in this case, the system swears on the duplicate Content. When x:Shared="False"
when is created Resource for each element whenever it its request. Quote from MSDN
:
When set to false, modifies WPF resource-retrieval behavior so that requests for the attributed resource create a new instance for each request instead of sharing the same instance for all requests.
Example:
<Window.Resources>
<Canvas x:Key="Ampel" x:Shared="False">
<Rectangle Fill="Black" HorizontalAlignment="Left" Height="52" Stroke="Black" VerticalAlignment="Top" Width="50"/>
<Ellipse x:Name="RedGreen" Fill="Red" HorizontalAlignment="Left" Height="27" Margin="11,12,0,0" Stroke="Black" VerticalAlignment="Top" Width="28" />
</Canvas>
</Window.Resources>
<Grid>
<ContentControl Name="MyContentControl" Content="{StaticResource Ampel}" HorizontalAlignment="Left" />
<Label Name="MyLabel" Content="{StaticResource Ampel}" HorizontalAlignment="Center" />
<ContentPresenter Name="MyContentPresenter" Content="{StaticResource Ampel}" HorizontalAlignment="Center" VerticalAlignment="Center" />
</Grid>
To change the Fill
of Ellipse in code-behind, you can like this:
private void ChangeBackground_Click(object sender, RoutedEventArgs e)
{
var canvas = MyContentControl.Content as Canvas;
if (canvas != null)
{
foreach (var item in canvas.Children)
{
if (item is Ellipse)
{
((Ellipse)item).Fill = Brushes.Green;
}
}
}
}