Fix issues and rename.

src/Shared/HandyControlDemo_Shared/UserControl/Styles/DataGridDemoCtl.xaml

@@ -9,7 +9,7 @@
     <hc:TransitioningContentControl>
         <TabControl Style="{StaticResource TabControlInLine}">
             <TabItem Header="{ex:Lang Key={x:Static langs:LangKeys.Common}}">
-                <DataGrid HeadersVisibility="All" RowHeaderWidth="60" AutoGenerateColumns="False" ItemsSource="{Binding DataList}">
+                <DataGrid hc:DataGridAttach.CanUnselectRowsWithBlankArea="True" HeadersVisibility="All" RowHeaderWidth="60" AutoGenerateColumns="False" ItemsSource="{Binding DataList}">
                     <DataGrid.RowHeaderTemplate>
                         <DataTemplate>
                             <CheckBox IsChecked="{Binding IsSelected,RelativeSource={RelativeSource AncestorType=DataGridRow}}"/>

src/Shared/HandyControl_Shared/Controls/Attach/DataGridAttach.cs

@@ -312,20 +312,21 @@ namespace HandyControl.Controls
         /// <summary>
         /// 在 <see cref="DataGrid"/> 中点击空白地方取消选择所有 Row 和 Cell
         /// </summary>
-        public static readonly DependencyProperty ClickBlankUnselectProperty =
-            DependencyProperty.RegisterAttached("ClickBlankUnselect", typeof(bool), typeof(DataGridAttach), new PropertyMetadata(false, ClickBlankUnselectPropertyChanged));
+        public static readonly DependencyProperty CanUnselectRowsWithBlankAreaProperty =
+            DependencyProperty.RegisterAttached("CanUnselectRowsWithBlankArea", typeof(bool), typeof(DataGridAttach),
+                                                new PropertyMetadata(false, OnCanUnselectRowsWithBlankAreaChanged));
 
-        public static bool GetClickBlankUnselect(DependencyObject obj)
+        public static bool GetCanUnselectRowsWithBlankArea(DependencyObject obj)
         {
-            return (bool)obj.GetValue(ClickBlankUnselectProperty);
+            return (bool)obj.GetValue(CanUnselectRowsWithBlankAreaProperty);
         }
 
-        public static void SetClickBlankUnselect(DependencyObject obj, bool value)
+        public static void SetCanUnselectRowsWithBlankArea(DependencyObject obj, bool value)
         {
-            obj.SetValue(ClickBlankUnselectProperty, value);
+            obj.SetValue(CanUnselectRowsWithBlankAreaProperty, value);
         }
 
-        public static void ClickBlankUnselectPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
+        public static void OnCanUnselectRowsWithBlankAreaChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
         {
             if (d is DataGrid dataGrid && e.NewValue is bool enabled)
             {
@@ -338,19 +339,10 @@ namespace HandyControl.Controls
 
         private static void DataGrid_PreviewMouseDown(object sender, System.Windows.Input.MouseButtonEventArgs e)
         {
-            if (sender is DataGrid dataGrid)
+            if (sender is DataGrid dataGrid && e.OriginalSource is System.Windows.Controls.ScrollViewer)
             {
-                var dependencyObject = e.OriginalSource as DependencyObject;
-                while (dependencyObject != null && !(dependencyObject is DataGridRow))
-                {
-                    dependencyObject = VisualTreeHelper.GetParent(dependencyObject);
-                }
-
-                if (dependencyObject == null)
-                {
-                    dataGrid.CommitEdit();
-                    dataGrid.UnselectAll();
-                }
+                dataGrid.CommitEdit();
+                dataGrid.UnselectAll();
             }
         }
     }