WPF中的拖放1

<Window x:Class="WpfApplication8.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="350" Width="525">
    <Grid>
        <Canvas Margin="0,0,216,0" Name="canvas1" Background="Crimson" AllowDrop="True" Drop="C1Drop">
            <Rectangle Height="100" Margin="10,10" Name="rectangle1"  Width="100" Fill="Azure" PreviewMouseMove="RectMove" />
        </Canvas>
        <Canvas HorizontalAlignment="Right" Margin="0,0,0,0" Name="canvas2" 
                Width="199" Background="DarkSalmon" AllowDrop="True" Drop="C2Drop"/>
    </Grid>
</Window>

        private void C1Drop(object sender, DragEventArgs e)
        {
            if (e.Data.GetDataPresent(typeof(Rectangle)))
            {
                string str = ((Canvas)(this.rectangle1.Parent)).Name.ToString();                
                if(str.Equals("canvas2"))
                {
                    Rectangle rect = (Rectangle)e.Data.GetData(typeof(Rectangle));
                    this.canvas2.Children.Remove(rect);
                    this.canvas1.Children.Add(rect);
                }
              
            }
        }
        private void C2Drop(object sender, DragEventArgs e)
        {
            if (e.Data.GetDataPresent(typeof(Rectangle)))
            {
                string str = ((Canvas)(this.rectangle1.Parent)).Name.ToString();
                if (str.Equals("canvas1"))
                {
                    Rectangle rect = (Rectangle)e.Data.GetData(typeof(Rectangle));
                    this.canvas1.Children.Remove(rect);
                    this.canvas2.Children.Add(rect);
                }
            }
        }
        private void RectMove(object sender, MouseEventArgs e)
        {
            if (e.LeftButton == MouseButtonState.Pressed)       // 如果鼠标左键被按下
            {
                DataObject data = new DataObject(typeof(Rectangle), this.rectangle1);
                DragDrop.DoDragDrop(this.rectangle1, data, DragDropEffects.Move);
            }
        }