SPLITTER
Senkrechter Splitter
<Grid Name="GridSplitter" Grid.Column="0" Grid.Row="2"  >
  <Grid.RowDefinitions>               
     <RowDefinition Height="*"/>
  </Grid.RowDefinitions>
  <Grid.ColumnDefinitions>
     <ColumnDefinition Width="200"/>
     <ColumnDefinition Width="*"/>
  </Grid.ColumnDefinitions>
 
  <TextBox Name="tLinks" Grid.Column="0" Grid.Row="0">links</TextBox>
  <TextBox Name="tRechts" Grid.Column="1" Grid.Row="0">rechts</TextBox>
  <GridSplitter Name="splitterline" Grid.Column="0" Grid.Row="0" Width="3"  Background="Red">
</Grid>

Senkrechter Splitter

Horizontaler Splitter
<Grid>
  <Grid.RowDefinitions>
     <RowDefinition Height="*"/>
     <RowDefinition Height="auto"/>
     <RowDefinition Height="*"/>
  </Grid.RowDefinitions>
  <Grid.ColumnDefinitions>
      <ColumnDefinition Width="*"/>
  </Grid.ColumnDefinitions>

  <TextBox Name="tOben" Background="Yellow" Grid.Column="0" Grid.Row="0" AcceptsReturn="True">oben</TextBox>
  <TextBox Name="tUnten" Background="LightBlue" Grid.Column="0" Grid.Row="2" AcceptsReturn="True">unten</TextBox>
  <GridSplitter Name="gridsplitter" Grid.Column="0" Grid.Row="1" Background="Red" Height="4"   HorizontalAlignment="Stretch" />
</Grid>

Registry
ListView