GridSplitter Hide Column

[workgroupengineering]

I have xaml like this:

  <DockPanel>
    <CheckBox x:Name="Hide"
              DockPanel.Dock="Top"/>
    <Grid RowDefinitions="*" ColumnDefinitions="*,Auto,Auto">

      <Border Background="CadetBlue"
              Grid.Column="0">
      </Border>
      
      <GridSplitter Grid.Column="1" ResizeDirection="Columns"
                    IsVisible="{Binding !#Hide.IsChecked}"
                    Width="1"
                    Background="Black"/>
      
      <TextBlock Text="My Very Very Very Very Long Content" 
                 IsVisible="{Binding !#Hide.IsChecked}"
                 TextWrapping="Wrap"
                 Background="Red"
                 Foreground="White"                
                 Grid.Column="2"/>
    </Grid>

  </DockPanel>

When I check Hide CheckBox the grid behaves as I expected, but if I resize it with the GridSplitter before hiding, the space of column don't be reclaimed. What's my mistake?

[MarkusKgit]

It seems the GridSplitter sets the ColumnDefinition.Width so after dragging the grid splitter the ColumnDefinitions are altered and don't get restored when it is hidden:

[workgroupengineering]

Thanks for your reply, do you have any suggestions to get around this behavior?

[workgroupengineering]

I have resolved.

I create this Behavior

namespace Grid_IsVisible_Issue.Behaviors
{
    static class ColumnDefinition
    {
        private readonly static Avalonia.Controls.GridLength ZeroWidth = 
           new Avalonia.Controls.GridLength(0,Avalonia.Controls.GridUnitType.Pixel);

        private readonly static AttachedProperty<Avalonia.Controls.GridLength?> LastWidthProperty =
            AvaloniaProperty.RegisterAttached<Avalonia.Controls.ColumnDefinition, Avalonia.Controls.GridLength?>("LastWidth"
                , typeof(ColumnDefinition)
                , default );

        public readonly static AttachedProperty<bool> IsVisibleProperty =
             AvaloniaProperty.RegisterAttached<Avalonia.Controls.ColumnDefinition, bool>("IsVisible"
                 , typeof(ColumnDefinition)
                 , true
                 , coerce: ((element, visibility) =>
                      {

                          var lastWidth = element.GetValue(ColumnDefinition.LastWidthProperty);
                          if (visibility == true && lastWidth is { })
                          {
                              element.SetValue(Avalonia.Controls.ColumnDefinition.WidthProperty, lastWidth);
                          }
                          else if (visibility == false)
                          {
                              element.SetValue(LastWidthProperty, element.GetValue(Avalonia.Controls.ColumnDefinition.WidthProperty));
                              element.SetValue(Avalonia.Controls.ColumnDefinition.WidthProperty, ZeroWidth);
                          }
                          return visibility;
                      })
                 );

        public static bool GetIsVisible(Avalonia.Controls.ColumnDefinition columnDefinition)
        {
            return columnDefinition.GetValue(IsVisibleProperty);
        }

        public static void SetIsVisible(Avalonia.Controls.ColumnDefinition columnDefinition, bool visibility)
        {
             columnDefinition.SetValue(IsVisibleProperty,visibility);
        }
    }
}

and using like this:

    <Grid RowDefinitions="*">
      <Grid.ColumnDefinitions>
        <ColumnDefinition Width="*"/>
        <ColumnDefinition Width="Auto"/>
        <ColumnDefinition Width="Auto" lb:ColumnDefinition.IsVisible="{Binding !#Hide.IsChecked}" />
      </Grid.ColumnDefinitions>

      <Border Background="CadetBlue"
              Grid.Column="0">
      </Border>
      
      <GridSplitter Grid.Column="1" ResizeDirection="Columns"
                    IsVisible="{Binding !#Hide.IsChecked}"
                    Width="1"
                    Background="Black"/>
      
      <TextBlock Text="My Very Very Very Very Long Content"                  
                 TextWrapping="Wrap"
                 Background="Red"
                 Foreground="White"                
                 Grid.Column="2"/>
    </Grid>