Question

我正在玩WPF的玻璃边框，我发现了一个问题。当我扩展窗口的玻璃边框时，拖放功能将不再起作用...例如，拖动GridSplitter结束时会出现异常。

我的MainWindow的XAML：

<Window 
    x:Class="ChromeDragDrop.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:shell="clr-namespace:Microsoft.Windows.Shell;assembly=Microsoft.Windows.Shell"
    xmlns:local="clr-namespace:ChromeDragDrop"
    Title="MainWindow" Height="350" Width="525">
    <Window.Resources>
        <Style TargetType="{x:Type local:MainWindow}">
            <Setter Property="shell:WindowChrome.WindowChrome">
                <Setter.Value>
                    <shell:WindowChrome GlassFrameThickness="-1" ResizeBorderThickness="4" CaptionHeight="36"/>
                </Setter.Value>
            </Setter>
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="{x:Type local:MainWindow}">
                        <ContentPresenter Content="{TemplateBinding Content}"></ContentPresenter>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>
    </Window.Resources>
    <Grid Margin="50">
        <Grid.RowDefinitions>
            <RowDefinition Height="*"></RowDefinition>
            <RowDefinition Height="*"></RowDefinition>
        </Grid.RowDefinitions>    
        <Border Background="Lime" Opacity="0.8"></Border>
        <Border Background="Gray" Opacity="0.8" Grid.Row="1"></Border>
        <GridSplitter Background="Red" Height="10" ShowsPreview="True"  ResizeDirection="Rows" HorizontalAlignment="Stretch" Grid.Row="1" VerticalAlignment="Top"></GridSplitter>
    </Grid>
</Window>

例外：

System.NullReferenceException was unhandled
  Message=Object reference not set to an instance of an object.
  Source=PresentationFramework
  StackTrace:
       at System.Windows.Controls.GridSplitter.OnDragDelta(DragDeltaEventArgs e)
       at System.Windows.Controls.GridSplitter.OnDragDelta(Object sender, DragDeltaEventArgs e)
       at System.Windows.Controls.Primitives.DragDeltaEventArgs.InvokeEventHandler(Delegate genericHandler, Object genericTarget)
       at System.Windows.RoutedEventArgs.InvokeHandler(Delegate handler, Object target)
       at System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs)
       at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
       at System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args)
       at System.Windows.UIElement.RaiseEvent(RoutedEventArgs e)
       at System.Windows.Controls.Primitives.Thumb.OnMouseMove(MouseEventArgs e)
       at System.Windows.UIElement.OnMouseMoveThunk(Object sender, MouseEventArgs e)
       at System.Windows.Input.MouseEventArgs.InvokeEventHandler(Delegate genericHandler, Object genericTarget)
       at System.Windows.RoutedEventArgs.InvokeHandler(Delegate handler, Object target)
       at System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs)
       at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
       at System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args)
       at System.Windows.UIElement.RaiseTrustedEvent(RoutedEventArgs args)
       at System.Windows.UIElement.RaiseEvent(RoutedEventArgs args, Boolean trusted)
       at System.Windows.Input.InputManager.ProcessStagingArea()
       at System.Windows.Input.InputManager.ProcessInput(InputEventArgs input)
       at System.Windows.Input.InputProviderSite.ReportInput(InputReport inputReport)
       at System.Windows.Interop.HwndMouseInputProvider.ReportInput(IntPtr hwnd, InputMode mode, Int32 timestamp, RawMouseActions actions, Int32 x, Int32 y, Int32 wheel)
       at System.Windows.Interop.HwndMouseInputProvider.FilterMessage(IntPtr hwnd, WindowMessage msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
       at System.Windows.Interop.HwndSource.InputFilterMessage(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
       at MS.Win32.HwndWrapper.WndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
       at MS.Win32.HwndSubclass.DispatcherCallbackOperation(Object o)
       at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
       at MS.Internal.Threading.ExceptionFilterHelper.TryCatchWhen(Object source, Delegate method, Object args, Int32 numArgs, Delegate catchHandler)
       at System.Windows.Threading.Dispatcher.InvokeImpl(DispatcherPriority priority, TimeSpan timeout, Delegate method, Object args, Int32 numArgs)
       at MS.Win32.HwndSubclass.SubclassWndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam)
       at MS.Win32.UnsafeNativeMethods.DispatchMessage(MSG& msg)
       at System.Windows.Threading.Dispatcher.PushFrameImpl(DispatcherFrame frame)
       at System.Windows.Threading.Dispatcher.PushFrame(DispatcherFrame frame)
       at System.Windows.Application.RunDispatcher(Object ignore)
       at System.Windows.Application.RunInternal(Window window)
       at System.Windows.Application.Run(Window window)
       at System.Windows.Application.Run()
       at ChromeDragDrop.App.Main() in C:\Project\CSharp\Learn\WPF\ChromeGlass\ChromeDragDrop\ChromeDragDrop\obj\x86\Debug\App.g.cs:line 0
       at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)
       at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
       at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
       at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean ignoreSyncCtx)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
       at System.Threading.ThreadHelper.ThreadStart()
  InnerException:

我该怎么做才能解决这个问题？

Answer 1

您是否尝试在窗口根部添加AdronerDecorator？我得到了相同的异常，但在我的情况下，我的WPF控件托管在MFC窗口的HwndSource内。有关详细信息，请参阅this MS knowledgebase article。

Drag'n Drop问题扩展玻璃边框

1 个答案: