WPF DataGrid -禁用时保留选择

供将来参考，如果有人遇到同样的问题。
重新设置SelectedValue有很多副作用。
这是覆盖网格上的元数据的正确方法:

public class MyDataGrid : DataGrid
{
    static MyDataGrid()
    {
        IsEnabledProperty.OverrideMetadata(typeof(MyDataGrid), new CustomFrameworkPropertyMetadata(OnIsEnabledChanged));
    }
    /// <summary>
    /// Fixes the issue that the DataGrid's selection is cleared whenever the DataGrid is disabled.
    /// Tricky: this issue only happens for 4.0 installations, it is fixed in 4.5 (in-place upgrade) installations.
    /// </summary>
    /// <param name="d"></param>
    /// <param name="e"></param>
    private static void OnIsEnabledChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        d.CoerceValue(CanUserAddRowsProperty);
        d.CoerceValue(CanUserDeleteRowsProperty);
        //this is there in 4.0 dlls, not in the in-place upgrade 4.5 dlls.
        //if (!(bool)(e.NewValue))
        //{
        //    ((DataGrid)d).UnselectAllCells();
        //}
        CommandManager.InvalidateRequerySuggested();
    }
    class CustomFrameworkPropertyMetadata : FrameworkPropertyMetadata
    {
        public CustomFrameworkPropertyMetadata(PropertyChangedCallback propertyChangedCallback)
            : base(propertyChangedCallback)
        {
        }
        protected override void Merge(PropertyMetadata baseMetadata, DependencyProperty dp)
        {
            // See: http://msdn.microsoft.com/en-us/library/system.windows.propertymetadata.merge.aspx
            // See: http://msdn.microsoft.com/en-us/library/ms751554.aspx
            // By default, PropertyChangedCallbacks are merged from all owners in the inheritance hierarchy,
            // so all callbacks are called whenever the property changes.
            var thisPropertyChangedCallback = this.PropertyChangedCallback;
            base.Merge(baseMetadata, dp);
            // We do NOT want that default behavior here;
            // The callback of DataGrid should not be called here - it clears the selection, we don't want that.
            // But the callback of UIElement should be called here - it visually disabled the element, we still want that.
            if (baseMetadata.PropertyChangedCallback != null)
            {
                Delegate[] invocationList = baseMetadata.PropertyChangedCallback.GetInvocationList();
                PropertyChangedCallback inheritedPropertyChangedCallback = null;
                foreach (var invocation in invocationList)
                {
                    if (invocation.Method.DeclaringType == typeof(DataGrid))
                    {
                        // Do nothing; don't want the callback from DataGrid that clears the selection.
                    }
                    else
                    {
                        inheritedPropertyChangedCallback = inheritedPropertyChangedCallback == null
                            ? (PropertyChangedCallback)invocation
                            : (PropertyChangedCallback)Delegate.Combine(inheritedPropertyChangedCallback, invocation);
                    }
                }
                this.PropertyChangedCallback = thisPropertyChangedCallback != null
                                                   ? (PropertyChangedCallback)Delegate.Combine(inheritedPropertyChangedCallback, thisPropertyChangedCallback)
                                                   : inheritedPropertyChangedCallback;
            }
        }
    }
}

请注意，本文中提到的问题只发生在没有安装4.5的4.0安装中。
它在。net 4.5中是"固定的"，即使是针对4.0的应用程序也是如此("4.5是一个就地升级"的场景/痛苦)。

问候,
柯恩

我一般不会因为这个原因而禁用控件。我发现它要么崩溃的控制，保持其数据绑定当前，或者如果我必须保持它可见，但不允许任何类型的交互，把部分透明的黑色边框，它通常是崩溃，并成为可见的命令。

当IsHitTestVisible = false时，上下键的问题仍然存在。

所以我最终做的是重新制作自定义控件，像这样:

    public class FormMainDataGrid : DataGrid
    {
        public FormMainDataGrid() : base() {
            this.IsEnabledChanged += new DependencyPropertyChangedEventHandler(DataGrid_IsEnabledChanged);
            this.SelectionChanged += new SelectionChangedEventHandler(DataGrid_SelectionChanged);
        }
        private void DataGrid_SelectionChanged(object sender, SelectionChangedEventArgs args)
        {
            if (this.IsEnabled)
            {
                _selectedValue = this.SelectedValue;
            }
        }
        private object _selectedValue;
        private void DataGrid_IsEnabledChanged(object sender, DependencyPropertyChangedEventArgs args)
        {
            this.Dispatcher.BeginInvoke((Action)(() =>
            {
                this.SelectedValue = _selectedValue;
            }), null);
        }
    }

这个工作得很好…我必须要小心，因为当控件被禁用时改变SelectedValue会让它偏离轨道。

所以在结论中，我相信你的解决方案是最完整的，但我的允许我保持我的形式的代码精益& &;尽量平均。

谢谢你的帮助!