[WPF]拖拽改变区域大小

<Window x:Class="WPFTest.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="MainWindow" Height="Auto" Width="Auto">
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition Width="*"/>
</Grid.ColumnDefinitions>
<DockPanel Grid.Row="0" Grid.Column="0">
<TreeView>
<TreeViewItem Header="A00">
<TreeViewItem Header="A01"/>
<TreeViewItem Header="A02"/>
<TreeViewItem Header="A03"/>
<TreeViewItem Header="A04"/>
</TreeViewItem>
<TreeViewItem Header="B00">
<TreeViewItem Header="B01"/>
<TreeViewItem Header="B02"/>
<TreeViewItem Header="B03"/>
<TreeViewItem Header="B04"/>
</TreeViewItem>
<TreeViewItem Header="C00">
<TreeViewItem Header="C01"/>
<TreeViewItem Header="C02"/>
<TreeViewItem Header="C03"/>
<TreeViewItem Header="C04"/>
</TreeViewItem>
<TreeViewItem Header="D00">
<TreeViewItem Header="D01"/>
<TreeViewItem Header="D02"/>
<TreeViewItem Header="D03"/>
<TreeViewItem Header="D04"/>
</TreeViewItem>
</TreeView>
</DockPanel>
<GridSplitter Grid.Row="0" Grid.Column="1" Width="3" Margin="2,0,2,0" Background="Purple"
VerticalAlignment="Stretch" HorizontalAlignment="Center"/>
<DockPanel Grid.Row="0" Grid.Column="2">
<ListView>
<ListViewItem>E00</ListViewItem>
<ListViewItem>F00</ListViewItem>
<ListViewItem>G00</ListViewItem>
<ListViewItem>H00</ListViewItem>
<ListViewItem>I00</ListViewItem>
<ListViewItem>J00</ListViewItem>
<ListViewItem>K00</ListViewItem>
<ListViewItem>L00</ListViewItem>
</ListView>
</DockPanel>
</Grid>
</Window>