wpf gridsplitter issues -- both sides shrink

Question

Gridsplitter trouble:

I have a: grid with 4 columns

• Column 0 contains a grid with 3 columns
• Column 1 contains a gridsplitter
• Column 2 contains a stackpanel of width 20 pixels
• Column 3 contains a grid with 3 columns

When the gridsplitter is moved to either the left or right, BOTH panels shrink the same amount -- one should shrink and the other should grow.

I am hesitant to include the xaml, but you are going to ask for it, so here is an abridged version. I have only removed a few unrelated controls, and gutted the treeviews and listviews. If you really need the whole thing, then of course I can supply it.

Thanks for any help!

<Window x:Class="Calvin.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        Title="Calvin" >
    <DockPanel Height="Auto" Width="Auto" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" LastChildFill="True" >
        <Grid DockPanel.Dock="Top" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" RenderTransformOrigin="0.5,0.497" >
            <Grid.ColumnDefinitions>
                <ColumnDefinition Width="1*" />
                <ColumnDefinition Width="5"  />
                <ColumnDefinition Width="20"  />
                <ColumnDefinition Width="1*" />
            </Grid.ColumnDefinitions>
            <Grid.RowDefinitions>
                <RowDefinition Height="Auto"/>
            </Grid.RowDefinitions>
            <Grid Grid.Column="0" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" >
                <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="1*" />
                    <ColumnDefinition Width="5" />
                    <ColumnDefinition Width="2*" />
                </Grid.ColumnDefinitions>
                <Grid.RowDefinitions>
                    <RowDefinition Height="Auto"/>
                    <RowDefinition Height="Auto"/>
                </Grid.RowDefinitions>
                <TextBox Grid.Row="0" Grid.Column="0" Grid.ColumnSpan="3"  TextWrapping="NoWrap" Text="Field One"  HorizontalAlignment="Stretch"/>
                <TextBox Grid.Row="0" Grid.Column="4" Grid.ColumnSpan="3"  TextWrapping="NoWrap" Text="Field Two"  HorizontalAlignment="Stretch" />
                <TreeView DockPanel.Dock="Left" Grid.Column="0" Grid.Row="1" Name="PaneOneTree" 
                          Width="Auto"  HorizontalAlignment="Stretch" VerticalAlignment="Stretch" >
                </TreeView>
                <GridSplitter Grid.Column="1" Grid.Row="1" Width="5" HorizontalAlignment="Center"/>
                <ScrollViewer Grid.Column="2" Grid.Row="1" >
                    <ListView DockPanel.Dock="Left" Name="FileDetailsLeft" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Width="Auto" >
                        <ListView.View>
                            <GridView>
                                <GridViewColumn Header="Name" Width="120"  />
                                <GridViewColumn Header="Size" Width="120"  />
                                <GridViewColumn Header="Access Time" Width="120"  />
                                <GridViewColumn Header="Extension" Width="120"  />
                            </GridView>
                        </ListView.View>
                    </ListView>
                </ScrollViewer>
            </Grid>
            <GridSplitter Grid.Column="1" Grid.Row="0" Width="5" HorizontalAlignment="Left" />
            <StackPanel Grid.Column="2" Grid.Row="1" VerticalAlignment="Stretch" HorizontalAlignment="Center" Width="Auto" Background="Red">
                <Button  >Move</Button>
                <Button >Other</Button>
            </StackPanel>
            <Grid Grid.Column="3" Grid.Row="1" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" >
                <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="auto" />
                    <ColumnDefinition Width="5" />
                    <ColumnDefinition Width="auto" />
                </Grid.ColumnDefinitions>
                <Grid.RowDefinitions>
                    <RowDefinition Height="Auto"/>
                    <RowDefinition Height="Auto"/>
                </Grid.RowDefinitions>
                <TextBox Grid.Row="0" Grid.Column="0" Grid.ColumnSpan="3"  TextWrapping="NoWrap" Background="Cornsilk"
                         Text="Pane Two Text"  HorizontalAlignment="Stretch"/>
                <TextBox Grid.Row="0" Grid.Column="4" Grid.ColumnSpan="3"  TextWrapping="NoWrap"
                         Text="Pane Two Text"  HorizontalAlignment="Stretch" Background="Linen" />
                <TreeView DockPanel.Dock="Left" Grid.Column="0" Grid.Row="1" Name="PaneTwoTree" Width="Auto"  HorizontalAlignment="Stretch" VerticalAlignment="Stretch"
                          Background="SeaShell" >
                </TreeView>
                <GridSplitter Grid.Column="1" Grid.Row="1" Width="5" HorizontalAlignment="Center" />
                <ScrollViewer Grid.Column="2" Grid.Row="1" >
                    <ListView DockPanel.Dock="Left" Name="FileDetailsRight" 
                              HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Width="Auto" Background="Moccasin" >
                        <ListView.View>
                            <GridView>
                                <GridViewColumn Header="Name" Width="120"  />
                                <GridViewColumn Header="Size" Width="120"  />
                                <GridViewColumn Header="Access Time" Width="120"  />
                                <GridViewColumn Header="Extension" Width="120"  />
                            </GridView>
                        </ListView.View>
                        <ListViewItem >List Item</ListViewItem>
                        <ListViewItem >List Item</ListViewItem>
                        <ListViewItem >List Item</ListViewItem>
                        <ListViewItem >List Item</ListViewItem>
                        <ListViewItem >List Item</ListViewItem>
                        <ListViewItem >List Item</ListViewItem>
                        <ListViewItem >List Item</ListViewItem>
                    </ListView>
                </ScrollViewer>
            </Grid>
        </Grid>
    </DockPanel>
</Window>

And, of course, feel free to suggest better ways to do anything:) -- I'm still learning.

:bp:

Pellmell

-1 Your problem is not reproducible from your code example, even after spending ages removing all the references to code that you did not include. If you edit your code example and provide a complete but concise working example that exhibits your problem, I'll gladly remove my down vote. For a start, you can remove all of the Binding and just set Heights and Widths to simulate the size of the controls with data in. – Chophouse

Thank you -- I did update the xaml code to a project that will demonstrate the problem. Thanks for any help. – Pellmell

Did you? I don't think you have quite done that yet... did you test your code that you entered here? I don't think that you did, as I can see that it won't even compile straight away. Please try again and actually make sure that you can load it into an empty project. – Chophouse

It was tested, but formatting removed portions of it -- how and why are a mystery. It appears to be complete now. – Pellmell

+1 Aha, success! Now I can take a look for you. – Chophouse

Answer 1

Ok, I see your problem now... basically, you can't set an exact Width on a column who's Width will be changed by a GridSplitter control. Instead, you can only set MinWidth and/or MaxWidth property on the ColumnDefinition, but be aware that you can then not use the "*" notation. Also, looking at the code example below, you can see that you could have stripped out a whole load more code for your question example... this was all that was required to demonstrate your problem (before I fixed it):

<Grid>
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="Auto" MinWidth="150" />
        <ColumnDefinition Width="5" />
        <ColumnDefinition Width="20" />
        <ColumnDefinition Width="*" MinWidth="150" />
    </Grid.ColumnDefinitions>
    <Grid.RowDefinitions>
        <RowDefinition Height="Auto"/>
    </Grid.RowDefinitions>
    <Rectangle Grid.Column="0" Fill="PowderBlue" />
    <GridSplitter Grid.Column="1" Background="Black" HorizontalAlignment="Stretch" />
    <Rectangle Grid.Column="2" Fill="Red" Height="100" />
    <Rectangle Grid.Column="3" Fill="Purple" />
</Grid>

Chophouse

"*" Notation works fine if both "VerticalAlignment" and "HorizontalAlignment" are set below; otherwise you could set default width only in pixels. – Georgianngeorgianna

Answer 2

I had the same issue. When I moved one GridSplitter it would also move the other (Usually in the opposite direction.). I eventually discovered that I had forgotten to set a property of the GridSplitter. For a GridSplitter you MUST have both vertical and horizontal properties set ie...

<Grid>
    <Grid.ColumnDefinitions>
        <ColumnDefinition/>
        <ColumnDefinition Width="Auto"/>
        <ColumnDefinition/>
    </Grid.ColumnDefinitions>
    <GridSplitter Grid.Column="1" Width="2" 
        VerticalAlignment="Stretch" HorizontalAlignment="Center"/>
</Grid>

Whine

Wow! Thank you. I had been struggling with this for quite a while. – Locksmith