C# WPF DataGrid-禁用时保留选择
我已经为此挣扎了一段时间了。我的应用程序中有一个主/详细布局，与其他许多人一样，我面临着DataGrid在禁用时失去选择的问题。基本上，在从列表中选择一个元素以填充一系列字段后，用户按“编辑”，这将禁用DataGrid并启用表单的所有字段。保存数据后，按“保存”按钮将恢复这些操作。。。向前走了很长一段路 我正在使用.NETFramework4中的VS2010开发Windows7 我的尝试：C# WPF DataGrid-禁用时保留选择,c#,wpf,datagrid,selection,C#,Wpf,Datagrid,Selection,我已经为此挣扎了一段时间了。我的应用程序中有一个主/详细布局，与其他许多人一样，我面临着DataGrid在禁用时失去选择的问题。基本上，在从列表中选择一个元素以填充一系列字段后，用户按“编辑”，这将禁用DataGrid并启用表单的所有字段。保存数据后，按“保存”按钮将恢复这些操作。。。向前走了很长一段路 我正在使用.NETFramework4中的VS2010开发Windows7 我的尝试： 1） 基于，我曾尝试在2009年6月版的WPF工具包中使用DataGrid，但我有同样的反应。 2） 基于
1） 基于，我曾尝试在2009年6月版的WPF工具包中使用DataGrid，但我有同样的反应。
2） 基于，我尝试基于DataGrid创建一个自定义控件，并重写OniseEnabledChanged调用以删除对“UnselectAllCells”的调用，但由于没有代码示例，我甚至无法让它触发一次。我试过：
public class FormMainDataGrid : DataGrid
{
static FormMainDataGrid()
{
IsEnabledProperty.OverrideMetadata(typeof(FormMainDataGrid), new FrameworkPropertyMetadata(new PropertyChangedCallback(OnIsEnabledChanged)));
}
public FormMainDataGrid() : base() { }
private static void OnIsEnabledChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
d.CoerceValue(CanUserAddRowsProperty);
d.CoerceValue(CanUserDeleteRowsProperty);
//this was added in new version !!!
/*
if (!(bool)(e.NewValue))
{
((DataGrid)d).UnselectAllCells();
}
*/
// Many commands use IsEnabled to determine if they are enabled or not
CommandManager.InvalidateRequerySuggested();
}
}
public class FormMainDataGrid : DataGrid
{
static FormMainDataGrid()
{
}
public static void OverrideStuff()
{
IsEnabledProperty.OverrideMetadata(typeof(FormMainDataGrid), new FrameworkPropertyMetadata(new PropertyChangedCallback(OnIsEnabledChanged)));
}
public FormMainDataGrid() : base() { }
private static void OnIsEnabledChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
d.CoerceValue(CanUserAddRowsProperty);
d.CoerceValue(CanUserDeleteRowsProperty);
//this was added in new version !!!
/*
if (!(bool)(e.NewValue))
{
((DataGrid)d).UnselectAllCells();
}
*/
// Many commands use IsEnabled to determine if they are enabled or not
CommandManager.InvalidateRequerySuggested();
}
}
public partial class App : Application
{
protected override void OnStartup(StartupEventArgs e)
{
FormMainDataGrid.OverrideStuff();
base.OnStartup(e);
}
}
base.OnIsEnabledChanged非常感谢 我通常不会专门为此禁用控件。我发现更好的方法是要么折叠保持其数据绑定最新的控件，要么如果我必须使其可见但不允许任何类型的交互，将一个部分透明的黑色边框放置在其上，该边框通常会折叠并在命令中可见。使用上下键时仍然存在相同的问题，IshittesVisible=false 因此，我最终要做的是重新处理自定义控件，如下所示：
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);
}
}
谢谢你的帮助 如果有人遇到相同的问题，请以后参考
重新设置SelectedValue有很多副作用
这是覆盖网格上元数据的正确方法：
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;
}
}
}
}