wpf拖拽

简单拖拽的实现是，实现源控件的MouseDown事件，和目标控件Drop事件。调用DragDrop.DoDragDrop()以启动拖放操作，DragDrop.DoDragDrop()函数接受三个参数：dragSource、data以及allowedEffects。特别需要注意的 是dragSource参数。该参数标示了拖拽操作的消息源，也决定了所有的消息源事件由谁发出。参数data则用来包装Drag&Drop所操 作的数据。一般情况下，其都是一个DataObject类型的实例。该实例内部应包装拖拽所实际操作的数据。最后，allowedEffects可以用来 指定拖拽操作的效果。调用该函数的片断可以如下所示：

DragDrop.DoDragDrop(mListBox, dataObject, DragDropEffects.Copy);

例子1：从groupBox中拖动TextBlock控件到右侧Listbox中

xmal：

<Grid>
        <ListBox x:Name="listBox" Drop="listBox_Drop" HorizontalAlignment="Left" Height="190" Margin="285,10,0,0" VerticalAlignment="Top" Width="159" AllowDrop="True"/>
        <GroupBox x:Name="groupBox" Header="GroupBox" MouseDown="TextBlock_MouseDown" HorizontalAlignment="Left" Margin="23,10,0,0" VerticalAlignment="Top" Height="190" Width="247">
            <StackPanel Margin="10">
                <TextBlock Margin="10" >足球</TextBlock>
                <TextBlock Margin="10">篮球</TextBlock>
                <TextBlock Margin="10">羽毛球</TextBlock>
                <TextBlock Margin="10">乒乓球</TextBlock>
            </StackPanel>
        </GroupBox>

    </Grid>

C#

  private void TextBlock_MouseDown(object sender, MouseButtonEventArgs e)
        {
            TextBlock obj = (TextBlock)e.OriginalSource;
            DragDrop.DoDragDrop(obj, obj.Text, DragDropEffects.Copy);
        }

        private void listBox_Drop(object sender, DragEventArgs e)
        {
            string data = e.Data.GetData(DataFormats.Text).ToString();
            listBox.Items.Add(data);
        }

代码不难，自己应该可以看懂，这里不解释了.

 

例子2:从外部拖拽一个文件夹到窗体彩色框处，将显示文件夹地址和文件夹下所有文件信息

代码如下：

    <Grid Drop="textBox_Drop">
        <TextBlock x:Name="textBlock" Text="文件夹：" HorizontalAlignment="Left" Margin="10,35,0,0" TextWrapping="Wrap" VerticalAlignment="Top"/>
        <ListBox x:Name="listBox" HorizontalAlignment="Left" Height="176" Margin="10,100,0,0" VerticalAlignment="Top" Width="391"/>
        <TextBlock x:Name="textBlock1" HorizontalAlignment="Left" Margin="10,72,0,0" TextWrapping="Wrap" Text="文件夹下文件：" VerticalAlignment="Top"/>
        <TextBlock x:Name="textBlock2" HorizontalAlignment="Left" Margin="10,10,0,0" TextWrapping="Wrap" Text="请拖动文件夹到彩色框中" VerticalAlignment="Top"/>
        <TextBlock x:Name="txtfloder" HorizontalAlignment="Left" Margin="63,31,0,0" TextWrapping="Wrap" VerticalAlignment="Top" Width="328" Background="#FFCEDA41" Height="34"/>
    </Grid>

 private void textBox_Drop(object sender, DragEventArgs e)
        {
            if (e.Data.GetDataPresent(DataFormats.FileDrop))
            {
                listBox.Items.Clear();
                string floder = ((System.Array)e.Data.GetData(DataFormats.FileDrop)).GetValue(0).ToString();
                if (Directory.Exists(floder))
                {
                    txtfloder.Text = floder.ToString();
                    
                    foreach (var item in Directory.GetFiles(floder))
                    {
                        listBox.Items.Add(item);
                    }
                }
                else
                    txtfloder.Text = "无效文件夹";
            }
        }

例子3:把园从左拖动到右侧

  <Grid>
        <Canvas Name="canvas1" HorizontalAlignment="Left" Height="259" Margin="10,10,0,0" VerticalAlignment="Top" Width="228" Background="#FFEBEABC">
            <Ellipse Name="ell" PreviewMouseDown="ell_PreviewMouseMove" PreviewMouseMove="ell_PreviewMouseMove"  Fill="#FF9595E5" Height="100" Canvas.Left="28" Stroke="Black" Canvas.Top="23" Width="100"/>
        </Canvas>
        <Canvas Name="canvas2" Drop="c2_Drop" DragOver="canvas2_DragOver" HorizontalAlignment="Left" Height="259" Margin="256,10,0,0" VerticalAlignment="Top" Width="214" Background="#FFEDE2E2" AllowDrop="True"/>

    </Grid>

   private void ell_PreviewMouseMove(object sender, MouseEventArgs e)
        {
            if (e.LeftButton == MouseButtonState.Pressed)
            {
                DataObject obj = new DataObject(typeof(Ellipse), ell);
                DragDrop.DoDragDrop(this.ell, obj, DragDropEffects.Move);
            }
        }
        private void c2_Drop(object sender, DragEventArgs e)
        {
            if (e.Data.GetDataPresent(typeof(Ellipse)))
            {
                Ellipse obj = e.Data.GetData(typeof(Ellipse)) as Ellipse;
                canvas1.Children.Remove(obj);
                canvas2.Children.Add(obj);
            }
        }

        private void canvas2_DragOver(object sender, DragEventArgs e)
        {
            if (!e.Data.GetDataPresent(typeof(Ellipse)))
            {
                e.Effects = DragDropEffects.None;
                e.Handled = true;

            }
        }

这里的事件 PreviewMouseDown="ell_PreviewMouseMove" PreviewMouseMove="ell_PreviewMouseMove" ，可以只写其中一个即可。

 

详细查看msdn:https://msdn.microsoft.com/zh-cn/library/hh144799%28v=vs.110%29.aspx