我正在创建一个类型为 Window 的依赖属性。 有人可以告诉我需要使用哪个 FrameworkPropertyMetadataOptions 标志吗

Question

I am trying to figure out which FrameworkPropertyMetadataOptions flag to use for Window type.

public static readonly DependencyProperty RootWindowProperty;

static VideoPlayer() { FrameworkPropertyMetadata metadata = new FrameworkPropertyMetadata(new Window(), ...); // I don't know which flags to use here RootWindowProperty = DependencyProperty.Register( "RootWindow", typeof(Window), typeof(VideoPlayer), metadata);

}

Answer 1

Note, that it is best practice to use field initializers (inline) instead of static constructors (see example below).
The runtime is able to optimize the performance of types that don't have an explicitly defined static constructor.

You don't have to set any meta data flags:

class VideoPlayer : DependencyObject
{
  public static readonly DependencyProperty RootWindowProperty = DependencyProperty.Register(
    "RootWindow", 
    typeof(Window),
    typeof(VideoPlayer),
    new PropertyMetadata(default));

  public Window RootWindow
  {
    get => (Window)GetValue(RootWindowProperty);
    set => SetValue(RootWindowProperty, value); 
  }
}

See Microsoft Docs: Custom Dependency Properties to learn about Setting Appropriate Metadata Flags .