Custom Controls

You can write Page and UserControl classes in plugins just as you would in any WinUI project. The part to change is how the control loads its XAML.

After creating a control, open its .xaml.cs file and replace InitializeComponent() in the constructor with LoadComponent:

UserControl1.xaml.cs

using CustomExtensions.WinUI;
using Microsoft.UI.Xaml.Controls;

namespace ShadowExample.Plugin.Emoji.Controls;

public sealed partial class UserControl1 : UserControl
{
    public UserControl1()
    {
        this.LoadComponent(ref _contentLoaded);
    }
}

This lets the control find its XAML inside the plugin. WinUI already generates _contentLoaded, so you don't need to declare it.

Create controls after the plugin has loaded, and keep only the LoadComponent call shown above. Controls written entirely in code don't need this step.

If you generate constructors with [Autowired], put the call in partial void ConstructorInit(); see Quick Dependency Injection. For images in the UI, see Plugin Resource Paths.