WPF でガラスの境界線をいじっていて、問題が見つかりました。ウィンドウのガラス枠を拡張すると、ドラッグ アンド ドロップ機能が機能しなくなります。たとえば、GridSplitter をドラッグすると例外が発生します。
私の MainWindow の 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:
この問題を解決するにはどうすればよいですか?