我拖动的对象没有出现在 canvas 上？

Question

当我运行程序并尝试将椭圆拖放到 canvas 上时，椭圆没有出现在 canvas 上。虽然鼠标光标显示我正在拖动某些东西并且可以放在 canvas 上。有什么想法吗？

已解决：原来我是想放在它来自的对象上而不是canvas我想把它放在（Ellipse 而不是 Canvas)！感谢您的解决方案和信息 link Herdo.

后面的代码：

    private void Ellipse_MouseMove(object sender, MouseEventArgs e)
    {
        Ellipse bal = (Ellipse)sender;
        if (e.LeftButton == MouseButtonState.Pressed)
        {
            DataObject sleepbal = new DataObject("sleepbal", bal);
            DragDrop.DoDragDrop(bal, sleepbal, DragDropEffects.Copy);               
        }
    }
    private void Ellipse_Drop(object sender, DragEventArgs e)
    {
        Ellipse ellipse = (Ellipse)sender; ;
        if (ellipse != null)
        {
            if (e.Data.GetDataPresent("sleepbal"))
            {
                string dataString = (string)e.Data.GetData(DataFormats.StringFormat);
                BrushConverter converter = new BrushConverter();
                if (converter.IsValid(dataString))
                {
                    Brush nieuweKleur = (Brush)converter.ConvertFromString(dataString);
                    ellipse.Fill = nieuweKleur;
                    Positie = Mouse.GetPosition(AchtergrondCanvas);
                    Canvas.SetLeft(sleepBal, Positie.X);
                    Canvas.SetTop(sleepBal, Positie.Y);
                    AchtergrondCanvas.Children.Add(ellipse);
                }
            }
        }
    }

XAML:

    <Canvas Name="AchtergrondCanvas" Height="400" Width="500" AllowDrop="True"></Canvas>

    <Ellipse Name="VoorbeeldBal" Fill="{Binding SelectedValue, ElementName=BalKleurComboBox}"
                    MouseMove="Ellipse_MouseMove" Drop="Ellipse_Drop"/>

Answer 1

原来我是想把它放在它来自的物体上而不是 canvas 我希望它被放在上面！

感谢您的解决方案和信息link Herdo。

我拖动的对象没有出现在 canvas 上？

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c#

wpf

canvas

drag