Why rectangle's radius gets ignored in this situation? - xamarin.forms

Question

I have a Xamarin.Forms (v5.0.0.2515) project.
I have encountered this strange behavior using this scenario:
I have a view with 5 rectangles. RadiusX/RadiusY for each rectangle is 20.
I assign this view to a ContentView and everything looks normal (Fig. 1)
I assign another view to the ContentView
I assign back the view to the ContentView and rounded borders are gone (Fig. 2)
What can cause this issue?
This is a sample code to reproduce the issue.
using Xamarin.Forms;
namespace App
{
public class SamplePage : ContentPage
{
public SamplePage()
{
var grid = new Grid
{
RowDefinitions = new RowDefinitionCollection
{
new RowDefinition { Height = GridLength.Auto },
new RowDefinition { Height = GridLength.Star }
}
};
var btn = new Button { Text = "Replace the view!" };
Grid.SetRow(btn, 0);
grid.Children.Add(btn);
var rect = new Xamarin.Forms.Shapes.Rectangle
{
RadiusX = 20,
RadiusY = 20,
Fill = Brush.Azure,
StrokeThickness = 3,
Stroke = Brush.Black
};
var cv = new ContentView { Content = rect };
Grid.SetRow(cv, 1);
grid.Children.Add(cv);
btn.Clicked += (_, __) =>
{
cv.Content = new Label();
cv.Content = rect;
};
Content = grid;
}
}
}
Thanks.
Fig. 1
Fig. 2

Answer 1

According to your demo you provided, I found that the code cv.Content = new Label(); caused the problem. I changed the demo and you can check.
public partial class MainPage : ContentPage
{
public MainPage()
{
var grid = new Grid
{
RowDefinitions = new RowDefinitionCollection
{
new RowDefinition { Height = GridLength.Auto },
new RowDefinition { Height = GridLength.Star }
}
};
var btn = new Button { Text = "Replace the view!" };
Grid.SetRow(btn, 0);
grid.Children.Add(btn);
var rect = new Xamarin.Forms.Shapes.Rectangle
{
RadiusX = 50,
RadiusY = 10,
Fill = Brush.Azure,
StrokeThickness = 10,
Stroke = Brush.Black
};
var rect2 = new Xamarin.Forms.Shapes.Rectangle
{
RadiusX = 20,
RadiusY = 20,
Fill = Brush.Azure,
StrokeThickness = 3,
Stroke = Brush.Black
};
var cv = new ContentView {Content = rect2};
Grid.SetRow(cv, 1);
grid.Children.Add(cv);
btn.Clicked += (_,__) =>
{
cv.Content = rect;
};
Content = grid;
}
}
}