Xamarin.Forms，创建可点击的框架（背景）

Question

As Button is limited to use images inside it in Xamarin.Forms And StackLayout does not support CornerRadius property, We decided to use Frame instead of them, the Tapped event is implemented but the problem is background does not change on clicking. So how can I create and set a clickable background to frame?

Answer 1

AFAIK you can't handle visual state in xamarin forms. But you can do something like below code to achieve the state transition using custom renderer.

public class CustomFrameRenderer : Xamarin.Forms.Platform.Android.AppCompat.FrameRenderer
{
    private Color backgroundColor;

    protected override void OnElementChanged(ElementChangedEventArgs<Frame> e)
    {
        base.OnElementChanged(e);
        backgroundColor = Element.BackgroundColor;
        Control.Touch += Control_Touch;
    }

    private void Control_Touch(object sender, TouchEventArgs e)
    {
        switch (e.Event.Action)
        {
            case MotionEventActions.Down:
                Element.BackgroundColor = Color.Green;
                break;
            case MotionEventActions.Up:
                Element.BackgroundColor = backgroundColor;
                break;
        }
    }
}

Note: Above code would affect all the frames so better subclass and create a new frame to avoid background color transition in the entire app.