Visual Studio中UWP自定义控件Edit a copy模板编辑问题求助

Hey Priyanga, sorry to hear you're stuck with this empty template problem when using the "Edit a copy" option for your UWP custom control in Visual Studio. Let's go through some tried-and-true fixes that usually get this sorted out:

• Verify your custom control's core setup
  First, make sure your control is configured properly so Visual Studio can locate its default template. Your control class needs two key things:

  • Inherit from a valid UWP base control (like Control).
  • Link to its default style via DefaultStyleKeyProperty.OverrideMetadata in the constructor. Here's a minimal working example:

    public class MyCustomControl : Control
    {
        public MyCustomControl()
        {
            DefaultStyleKey = typeof(MyCustomControl);
        }
    }
    

  Also, ensure you have a default template defined in Generic.xaml (under the Themes folder of your control project). Even a bare-bones template will work:

  <Style TargetType="local:MyCustomControl">
      <Setter Property="Template">
          <Setter.Value>
              <ControlTemplate TargetType="local:MyCustomControl">
                  <Border Background="{TemplateBinding Background}"
                          BorderBrush="{TemplateBinding BorderBrush}"
                          BorderThickness="{TemplateBinding BorderThickness}">
                      <!-- Placeholder for your control content -->
                  </Border>
              </ControlTemplate>
          </Setter.Value>
      </Setter>
  </Style>
  

• Clean and rebuild your solution
  Visual Studio's build cache can sometimes cause odd glitches like this. Go to Build > Clean Solution, wait for it to finish, then run Build > Rebuild Solution. Once done, try the "Edit a copy" option again.

• Double-check your selected control
  Make sure you've actually selected an instance of your custom control (not a parent container or unrelated control) in either the XAML designer or code editor. Right-clicking the correct control instance before choosing Edit Template > Edit a copy ensures VS targets the right template source.

• Update Visual Studio and UWP SDK
  Older versions of Visual Studio or outdated UWP SDKs might have bugs that lead to empty templates. Update Visual Studio to the latest stable release, and ensure your project's Target SDK and Minimum SDK versions are compatible (aim for the latest Target SDK with a reasonable Minimum SDK that fits your app's needs).

• Fallback to manual template creation
  If all else fails, you can create the template copy manually:

  1. Add a new Resource Dictionary to your project (Right-click project > Add > New Item > Resource Dictionary).
  2. Copy the default template from Generic.xaml into this new dictionary.
  3. Modify the template as needed, then reference the dictionary in your page's resources or directly assign the style to your control.

内容的提问来源于stack exchange，提问作者priyanga