GridSplitter

The GridSplitter control is a control that allows a user to resize the space between Grid rows or columns.

<Grid ColumnDefinitions="*, 4, *">
    <Rectangle Grid.Column="0" Fill="Blue"/>
    <GridSplitter Grid.Column="1" Background="Black" ResizeDirection="Columns"/>
    <Rectangle Grid.Column="2" Fill="Red"/>
</Grid>

GridSplitter in Action for Columns

<Grid RowDefinitions="*, 4, *">
    <Rectangle Grid.Row="0" Fill="Blue"/>
    <GridSplitter Grid.Row="1" Background="Black" ResizeDirection="Rows"/>
    <Rectangle Grid.Row="2" Fill="Red"/>
</Grid>

GridSplitter in Action for Rows

Reference

GridSplitter

Source code

GridSplitter.cs