GridSplitter resizes incorrectly

Question

On a Page derived class, I have some nested Grids.

I have changed the ColumnDefinition to the width of some pixels (i.e. around 5), with some columns having the width of "*".

All elements have Width="Auto".

Here is my Splitter:

<Grid Margin="10"
          HorizontalAlignment="Stretch"
          VerticalAlignment="Stretch"
          Grid.Background="SpringGreen">

        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="5" />
            <ColumnDefinition Width="5*" />
            <ColumnDefinition Width="5" />
            <ColumnDefinition Width="5" />
            <ColumnDefinition Width="5" />
            <ColumnDefinition Width="5*" />
            <ColumnDefinition Width="5" />

        </Grid.ColumnDefinitions>
        <Grid.RowDefinitions>
            <RowDefinition Height="5*" />

        </Grid.RowDefinitions>

        <GridSplitter Grid.Row="1"
                      Grid.Column="3"
                      Width="Auto"
                      Height="Auto"
                      Margin="0"
                      HorizontalAlignment="Stretch"
                      VerticalAlignment="Stretch"
                      Background="Red"
                      BorderThickness="1,0"
                      Cursor="SizeWE"
                      RenderTransformOrigin="-1,1"
                      ShowsPreview="True" />
    </Grid>

So the problem is, it does almost no resizing to the left, but very much to the right. It is not depending on the window size, even in fullscreen, the splitter only allows some pixels to the left.

-edit- Are there any known problems that I did not find myself (on Google)? Anyone experienced similar strange behaviour?

-edit update- Found a minimum definition for the grid to reproduce the problem.

Answer 1

You have 3 columns of width 5 between the two *-width columns. The GridSplitter is in the middle of these. It works by resizing the preceding column (i.e. the first of your 5 pixel columns). You can't resize to the left because that column is only 5 pixels wide.

Remember that Row and Column properties are zero-based.