Force redraw of Xamarin.Forms View with custom renderer

Question

I have a visual element MyButton with a custom renderer implemented for iOS.

Shared:

namespace RendererTest
{
    public class MyButton: But         


        

Answer 1

First, turn you BoundaryColor into a bindable property. That's not required, firing INPC event is enough, but then you can bind to it:

public static readonly BindableProperty BoundaryColorProperty =
    BindableProperty.Create ("BoundaryColor", typeof(Color), typeof(MyButton), Color.Default);

public Color BoundaryColor {
    get { return (Color)GetValue (BoudaryColorProperty); }
    set { SetValue (BoundaryColorProperty, value); }
}

then, in your renderer:

protected override void OnElementPropertyChanged (object sender, PropertyChangedEventArgs e)
{
    base.OnElementPropertyChanged (sender, e);

    if (e.PropertyName == MyButton.BoundaryColorProperty.PropertyName)
        SetNeedsDisplay ();
}