对于拖放操作有两个方面：源和目标。为了创建拖放源，需要在某个位置调用DragDrop.DoDragDrop()方法初始化拖放操作。此时确定拖动操作的源，搁置希望移动的内容，并指明充许什么样的拖放效果（复制，移动等）。
通常会在响应PreviewMouseDown或MouseDown事件时，调用DoDragDrop()方法。
而接收的元素需要将它的AllowDrop属性设置为true,还需要通过处理Drop事件来处理数据。
前台代码：
<
Grid
>
< Grid.RowDefinitions >
< RowDefinition Height ="*" ></ RowDefinition >
< RowDefinition Height ="*" ></ RowDefinition >
</ Grid.RowDefinitions >
< Grid.ColumnDefinitions >
< ColumnDefinition Width ="*" ></ ColumnDefinition >
< ColumnDefinition Width ="*" ></ ColumnDefinition >
</ Grid.ColumnDefinitions >
< TextBox Name ="source" Grid.Row ="0" Background ="Purple" Foreground ="White" MouseDown ="source_MouseDown" >博客园:www.cnblogs.com </ TextBox >
< Image Source ="http://static.cnblogs.com/images/logo_small.gif" Grid.Column ="1" Stretch ="None" MouseDown ="Image_MouseDown" ></ Image >
< Label Name ="target" Grid.Row ="1" Background ="YellowGreen" AllowDrop ="True" Drop ="OnDrop" >文本拖到这里 </ Label >
< Image Name ="targetImg" Grid.Row ="1" Grid.Column ="1" AllowDrop ="True" Drop ="targetImg_Drop_1" Stretch ="None" Source ="http://www.baidu.com/img/baidu_sylogo1.gif" ></ Image >
</ Grid >
< Grid.RowDefinitions >
< RowDefinition Height ="*" ></ RowDefinition >
< RowDefinition Height ="*" ></ RowDefinition >
</ Grid.RowDefinitions >
< Grid.ColumnDefinitions >
< ColumnDefinition Width ="*" ></ ColumnDefinition >
< ColumnDefinition Width ="*" ></ ColumnDefinition >
</ Grid.ColumnDefinitions >
< TextBox Name ="source" Grid.Row ="0" Background ="Purple" Foreground ="White" MouseDown ="source_MouseDown" >博客园:www.cnblogs.com </ TextBox >
< Image Source ="http://static.cnblogs.com/images/logo_small.gif" Grid.Column ="1" Stretch ="None" MouseDown ="Image_MouseDown" ></ Image >
< Label Name ="target" Grid.Row ="1" Background ="YellowGreen" AllowDrop ="True" Drop ="OnDrop" >文本拖到这里 </ Label >
< Image Name ="targetImg" Grid.Row ="1" Grid.Column ="1" AllowDrop ="True" Drop ="targetImg_Drop_1" Stretch ="None" Source ="http://www.baidu.com/img/baidu_sylogo1.gif" ></ Image >
</ Grid >
后台代码：
///
<summary>
/// 文本源数据
/// </summary>
private void source_MouseDown( object sender, MouseButtonEventArgs e)
{
TextBox objText = sender as TextBox;
DragDrop.DoDragDrop(objText, objText, DragDropEffects.Copy);
}
/// <summary>
/// 图片源数据
/// </summary>
private void Image_MouseDown( object sender, MouseButtonEventArgs e)
{
Image objImage = sender as Image;
DragDrop.DoDragDrop(objImage, objImage.Source, DragDropEffects.Copy);
}
/// <summary>
/// 目标位置
/// </summary>
private void OnDrop( object sender, DragEventArgs e)
{
if (e.Data.GetDataPresent(DataFormats.Text))
e.Effects = DragDropEffects.Copy;
else
return;
this.target.Content = e.Data.GetData(DataFormats.Text);
}
private void targetImg_Drop_1( object sender, DragEventArgs e)
{
e.Data.GetFormats();
if (e.Data.GetDataPresent( " System.Windows.Media.Imaging.BitmapFrameDecode "))
e.Effects = DragDropEffects.Copy;
else
{
return;
}
// targetImg.Source = (ImageSource)e.Data.GetData("System.Windows.Media.Imaging.BitmapFrameDecode");
((Image)sender).Source = (ImageSource)e.Data.GetData( " System.Windows.Media.Imaging.BitmapFrameDecode ");
}
/// 文本源数据
/// </summary>
private void source_MouseDown( object sender, MouseButtonEventArgs e)
{
TextBox objText = sender as TextBox;
DragDrop.DoDragDrop(objText, objText, DragDropEffects.Copy);
}
/// <summary>
/// 图片源数据
/// </summary>
private void Image_MouseDown( object sender, MouseButtonEventArgs e)
{
Image objImage = sender as Image;
DragDrop.DoDragDrop(objImage, objImage.Source, DragDropEffects.Copy);
}
/// <summary>
/// 目标位置
/// </summary>
private void OnDrop( object sender, DragEventArgs e)
{
if (e.Data.GetDataPresent(DataFormats.Text))
e.Effects = DragDropEffects.Copy;
else
return;
this.target.Content = e.Data.GetData(DataFormats.Text);
}
private void targetImg_Drop_1( object sender, DragEventArgs e)
{
e.Data.GetFormats();
if (e.Data.GetDataPresent( " System.Windows.Media.Imaging.BitmapFrameDecode "))
e.Effects = DragDropEffects.Copy;
else
{
return;
}
// targetImg.Source = (ImageSource)e.Data.GetData("System.Windows.Media.Imaging.BitmapFrameDecode");
((Image)sender).Source = (ImageSource)e.Data.GetData( " System.Windows.Media.Imaging.BitmapFrameDecode ");
}
如果不知道拖放源数据是什么数据类型，可以使用实现了IDataObject接口的GetFormats()方法。如: e.Data.GetFormats(); 其中Data就实现了IDataObject接口。
