WPF之实现控件内容拖动

以下分别记录label、listbox、treeview三个控件的拖动示例：

1.对被拖动控件，实现拖动事件，主要是通过各种鼠标事件，实现DragDrop.DoDragDrop方法。

2.对于需要拖动到的目的控件，需要实现AllowDrop="True" Drop="TargetLabel_Drop"

   <Window.Resources>

        <Style TargetType="ListBoxItem">

            <EventSetter Event="PreviewMouseMove" Handler="ListBox_PreviewMouseMove"/>

        </Style>

        <Style TargetType="TreeViewItem">

            <EventSetter Event="PreviewMouseMove" Handler="TreeView_PreviewMouseMove"/>

        </Style>

    </Window.Resources>

    <Grid>

        <Grid.ColumnDefinitions>

            <ColumnDefinition Width="7*"/>

            <ColumnDefinition Width="Auto"/>

            <ColumnDefinition Width="3*"/>

        </Grid.ColumnDefinitions>

        <StackPanel>

            <Label Name="Label" Margin="5,10" Content="This is Label" MouseDown="Label_MouseDown"/>

            <ListBox Margin="5,10">

                <ListBoxItem>000</ListBoxItem>

                <ListBoxItem>111</ListBoxItem>

                <ListBoxItem>222</ListBoxItem>

            </ListBox>

            <TreeView Name="treeView" Margin="5,10">

                <TreeViewItem Header="aa">

                    <TreeViewItem Header="00"/>

                    <TreeViewItem Header="11"/>

                    <TreeViewItem Header="22"/>

                </TreeViewItem>

            </TreeView>

            <Button Height="30" Margin="5,10" Name="btn" Content="Rest" Click="btn_Click"/>

        </StackPanel>

        <Rectangle Grid.Column="1" Fill="Red" Width="1"/>

        <Label Name="TargetLabel" Grid.Column="2" Content="Come here"  Background="AliceBlue" VerticalContentAlignment="Center" HorizontalContentAlignment="Center" AllowDrop="True" Drop="TargetLabel_Drop"/>

    </Grid>

  private void TargetLabel_Drop(object sender, DragEventArgs e)

        {

            var txt = e.Data.GetData(DataFormats.Text);

            this.TargetLabel.Content = txt;

        }

        private void btn_Click(object sender, RoutedEventArgs e)

        {

            this.TargetLabel.Content = "Come here";

        }

        private void Label_MouseDown(object sender, MouseButtonEventArgs e)

        {

            DragDrop.DoDragDrop(Label, Label.Content, DragDropEffects.Copy);

        }

        private void ListBox_PreviewMouseMove(object sender, MouseEventArgs e)

        {

            var item = sender as ListBoxItem;

            DragDrop.DoDragDrop(item, item.Content, DragDropEffects.Copy);

        }

        private void TreeView_PreviewMouseMove(object sender, MouseEventArgs e)

        {

            if (e.LeftButton==MouseButtonState.Released)

            {

                return;

            }

            var t = sender as TreeView;

            var x = this.treeView.SelectedItem;

            if (x==null)

            {

                return;

            }

            var item = x as TreeViewItem;

            DragDrop.DoDragDrop(item, item.Header, DragDropEffects.Copy);

        }