Merge pull request #6283 from workgroupengineering/fixes/Issue_6282

fixes(DataGrid): Fixes DataGridColumn IsVisible binding

samples/ControlCatalog/Pages/DataGridPage.xaml

@@ -23,16 +23,21 @@
     </StackPanel>
     <TabControl Grid.Row="2">
       <TabItem Header="DataGrid">
-        <DataGrid Name="dataGrid1" Margin="12" CanUserResizeColumns="True" CanUserReorderColumns="True" CanUserSortColumns="True" HeadersVisibility="All">
-          <DataGrid.Columns>
-            <DataGridTextColumn Header="Country" Binding="{Binding Name}" Width="6*" />
-            <!-- CompiledBinding example of usage. -->
-            <DataGridTextColumn Header="Region" Binding="{CompiledBinding Region}" Width="4*" x:DataType="local:Country" />
-            <DataGridTextColumn Header="Population" Binding="{Binding Population}" Width="3*" />
-            <DataGridTextColumn Header="Area" Binding="{Binding Area}" Width="3*" />
-            <DataGridTextColumn Header="GDP" Binding="{Binding GDP}" Width="3*" CellStyleClasses="gdp" />
-          </DataGrid.Columns>
-        </DataGrid>
+        <DockPanel>
+          <CheckBox x:Name="ShowGDP"  IsChecked="True"  Content="Toggle GDP Column Visibility"
+                    DockPanel.Dock="Top"/>
+          <DataGrid Name="dataGrid1" Margin="12" CanUserResizeColumns="True" CanUserReorderColumns="True" CanUserSortColumns="True" HeadersVisibility="All">
+            <DataGrid.Columns>
+              <DataGridTextColumn Header="Country" Binding="{Binding Name}" Width="6*" />
+              <!-- CompiledBinding example of usage. -->
+              <DataGridTextColumn Header="Region" Binding="{CompiledBinding Region}" Width="4*" x:DataType="local:Country" />
+              <DataGridTextColumn Header="Population" Binding="{Binding Population}" Width="3*" />
+              <DataGridTextColumn Header="Area" Binding="{Binding Area}" Width="3*" />
+              <DataGridTextColumn Header="GDP" Binding="{Binding GDP}" Width="3*" CellStyleClasses="gdp"
+                                  IsVisible="{Binding #ShowGDP.IsChecked}"/>
+            </DataGrid.Columns>
+          </DataGrid>
+        </DockPanel>
       </TabItem>
       <TabItem Header="Grouping">
         <DataGrid Name="dataGridGrouping" Margin="12">

src/Avalonia.Controls.DataGrid/DataGridColumn.cs

@@ -27,7 +27,6 @@ namespace Avalonia.Controls
         private double? _minWidth;
         private bool _settingWidthInternally;
         private int _displayIndexWithFiller;
-        private bool _isVisible;
         private object _header;
         private DataGridColumnHeader _headerCell;
         private IControl _editingElement;
@@ -40,7 +39,6 @@ namespace Avalonia.Controls
         /// </summary>
         protected internal DataGridColumn()
         {
-            _isVisible = true;
             _displayIndexWithFiller = -1;
             IsInitialDesiredWidthDetermined = false;
             InheritsWidth = true;
@@ -174,32 +172,42 @@ namespace Avalonia.Controls
             get => _editBinding;
         }
 
+
+        /// <summary>
+        /// Defines the <see cref="IsVisible"/> property.
+        /// </summary>
+        public static StyledProperty<bool> IsVisibleProperty =
+             Control.IsVisibleProperty.AddOwner<DataGridColumn>();
+
         /// <summary>
         /// Determines whether or not this column is visible.
         /// </summary>
         public bool IsVisible
         {
-            get
-            {
-                return _isVisible;
-            }
-            set
-            {
-                if (value != IsVisible)
-                {
-                    OwningGrid?.OnColumnVisibleStateChanging(this);
-                    _isVisible = value;
+            get => GetValue(IsVisibleProperty);
+            set => SetValue(IsVisibleProperty, value);
+        }
 
-                    if (_headerCell != null)
-                    {
-                        _headerCell.IsVisible = value;
-                    }
+        protected override void OnPropertyChanged<T>(AvaloniaPropertyChangedEventArgs<T> change)
+        {
+            base.OnPropertyChanged(change);
 
-                    OwningGrid?.OnColumnVisibleStateChanged(this);
+            if (change.Property == IsVisibleProperty)
+            {
+                OwningGrid?.OnColumnVisibleStateChanging(this);
+                var isVisible = (change as AvaloniaPropertyChangedEventArgs<bool>).NewValue.Value;
+
+                if (_headerCell != null)
+                {
+                    _headerCell.IsVisible = isVisible;
                 }
+
+                OwningGrid?.OnColumnVisibleStateChanged(this);
+                NotifyPropertyChanged(change.Property.Name);
             }
         }
 
+
         /// <summary>
         /// Actual visible width after Width, MinWidth, and MaxWidth setting at the Column level and DataGrid level
         /// have been taken into account