Create WPF ellipse from C# code and move it by mouse

Question

I have a canvas, and I need to put an (for example) ellipse on it, not from XAML but from code. So I do

Ellipse e1;

public MainWindow()
    {
        ...
        ... 
        e1 = new Ellipse();
        e1.Height = 100;
        e1.Width = 100;
        e1.Stroke = Brushes.Red;
        e1.StrokeThickness = 5;
        Canvas.SetLeft(e1,40);
        Canvas.SetTop(e1,50);
        e1.MouseDown += ellipse_MouseDown;
        Canvas1.Children.Add(e1);

    }

   private void ellipse_MouseDown(object sender, MouseButtonEventArgs e)
    {
        Ellipse el = (Ellipse)sender;
        el.Stroke = Brushes.Green;
        buttonAdd.Content = "New_TEXT";

    }

But it doesn't react on clicking. Anyway, I tried to add this ellipse_MouseDownmethod to ellipse that was created from XAML - and it works.

 <Canvas x:Name="Canvas1" HorizontalAlignment="Left" Height="421" Margin="10,10,0,0" VerticalAlignment="Top" Width="346">
      <Ellipse x:Name="ellipse" Fill="#FFF4F4F5" HorizontalAlignment="Left" Height="111" Margin="117,152,0,0" Stroke="Black" VerticalAlignment="Top" Width="131" MouseDown="ellipse_MouseDown" MouseMove="ellipse_MouseMove" MouseUp="ellipse_MouseUp"/>
  </Canvas>

Where can be a problem?

UPD.

According to Rohit Vats's answer just add

e1.Fill = Brushes.Transparent;

or

e1.Fill = new SolidColorBrush((Color)ColorConverter
                                       .ConvertFromString("#FFF4F4F5"));

'cause by default Fill is null which doesn't respond to mouse events

Please show the XAML that works, so we can compare it with the code that doesn't. — Jon Skeet
– Jon Skeet, Commented Dec 14, 2013 at 8:59

Rohit Vats · Accepted Answer · 2013-12-14 09:10:54Z

1

You need to set Fill to Transparent so that it can react to mouse events. By default Fill is null which doesn't respond to mouse events -

e1.Stroke = Brushes.Red;
e1.Fill = Brushes.Transparent; <-- HERE

UPDATE

As evident from XAML code, you are setting Fill to #FFF4F4F5 but not setting it from code behind.

e1.Fill = new SolidColorBrush((Color)ColorConverter
                                       .ConvertFromString("#FFF4F4F5"));

edited Dec 14, 2013 at 9:10

answered Dec 14, 2013 at 9:04

Rohit Vats

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1 Comment

Rohit Vats Over a year ago

Great. I have update with Fill color in case you don't want it to be transparent. Hope it resolves your query. :)

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