R – WPF: Setting named color to resource

colorsresourceswpfwpf-controls

I am modifying the control template of the WPF Calendar control to change the color of text and the Previous and Next arrows on the control. I want to set the color to a local SolidColorBrush resource called MyTextBrush.

The Previous and Next buttons have separate control templates, and each draws a Path object for its button's arrow. Here is the relevant markup for the Previous button:

<Path Margin="14,-6,0,0" Height="10" Width="6" VerticalAlignment="Center" HorizontalAlignment="Left" Stretch="Fill" Data="M288.75,232.25 L288.75,240.625 L283,236.625 z">
    <Path.Fill>
        <SolidColorBrush x:Name="TextColor" Color="#FF333333" />
    </Path.Fill>
</Path>

Note that the color is named TextColor, using the x:Name property.

Here is my problem: The x:Name property is required–WPF throws an exception if it is missing. That means I can't simply replace the entire brush with a reference to the MyTextBrush resource, because I would lose the x:Name value. So, how do I reference MyTextBrush, while still retaining the x:Name property for the brush in this particular control template?

Thanks for your help.

Best Answer

So, how do I reference MyTextBrush, while still retaining the x:Name property for the brush in this particular control template?

Regarding this problem it sounds like you are using a dodgy/fragile template. What control template is it?

  • If you have full source control of the template, remove references to the named element (most likely in a storyboard). They must be animating the brush for some reason.
  • The other option might be to just create another unused brush within your template (Perhaps on a hidden element) with the correct name to keep the template happy.
  • Lastly, you can try adding the x:Name onto the brush in the shared RD, but this is quite complicated and not sure its worth it!

Two more potential solutions:

  • Try binding just the Color property of the SCB... that should work as its a DP
  • Change the template animations so they do not use a named brush, but instead use a named parent then access the brush via the TargetProperty e.g. Storyboard.TargetProperty="(Shape.Fill).(SolidColorBrush.Color)" Storyboard.TargetName="myNamedParent"
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