Code:
/ DotNET / DotNET / 8.0 / untmp / WIN_WINDOWS / lh_tools_devdiv_wpf / Windows / wcp / Framework / System / Windows / Documents / WinEventHandler.cs / 2 / WinEventHandler.cs
//---------------------------------------------------------------------------- // //// Copyright (C) Microsoft Corporation. All rights reserved. // // // // Description: WinEventHandler implementation. // // History: // 02/04/2005 : [....] - created. // //--------------------------------------------------------------------------- using System; using System.Collections; using System.Runtime.InteropServices; using System.ComponentModel; using System.Diagnostics; using System.Security; using System.Security.Permissions; using System.Windows.Threading; using MS.Win32; using MS.Internal; namespace System.Windows.Documents { internal class WinEventHandler : IDisposable { //----------------------------------------------------- // // Constructors // //----------------------------------------------------- #region Constructors // ctor that takes a range of events ////// Critical - as this calls the setter for _winEventProc.Value. /// Safe - as this doesn't allow an arbitrary value to be set. /// [SecurityCritical, SecurityTreatAsSafe] internal WinEventHandler(int eventMin, int eventMax) { _eventMin = eventMin; _eventMax = eventMax; _winEventProc.Value = new NativeMethods.WinEventProcDef(WinEventDefaultProc); // Keep the garbage collector from moving things around _gchThis = GCHandle.Alloc(_winEventProc.Value); // Workaround for bug 150666. Dispatcher dispatcher = Dispatcher.CurrentDispatcher; if (dispatcher != null) { dispatcher.ShutdownFinished += new EventHandler(OnDispatcherShutDown); } } ~WinEventHandler() { Clear(); } #endregion Constructors //------------------------------------------------------ // // Internal Methods // //----------------------------------------------------- #region Internal Methods public void Dispose() { // no need to call this finalizer. GC.SuppressFinalize(this); Clear(); } // callback for the class inherited from this. internal virtual void WinEventProc(int eventId, IntPtr hwnd) { } ////// Critical: This code frees the gchandle and is critical because it calls GCHandle /// TreatAsSafe: Ok to call free on a handle that we have allocated /// [SecurityCritical,SecurityTreatAsSafe] internal void Clear() { // Make sure that the hooks is uninitialzied. Stop(); // free GC handle. if (_gchThis.IsAllocated) { _gchThis.Free(); } } // install WinEvent hook and start getting the callback. ////// Critical - as this calls SetWinEventHook which has a SUC on it and also calls /// the setter for _hHook. /// Safe - as this does not allow an arbitrary method to be set up as a hook and /// also doesn't allow an aribtrary value to be set on _hHook.Value. /// [SecurityCritical, SecurityTreatAsSafe] internal void Start() { if (_gchThis.IsAllocated) { _hHook.Value = UnsafeNativeMethods.SetWinEventHook(_eventMin, _eventMax, IntPtr.Zero, _winEventProc.Value, 0, 0, NativeMethods.WINEVENT_OUTOFCONTEXT); if (_hHook.Value == IntPtr.Zero ) { Stop(); } } } // uninstall WinEvent hook. ////// Critical - as this calls UnhookWinEvent which has a SUC on it and also /// calls the setter for _hHook.Value. /// Safe - as this does not allow an arbitrary hook to be removed and sets /// _hHook.Value to IntPtr.Zero which is safe. /// [SecurityCritical, SecurityTreatAsSafe] internal void Stop() { if (_hHook.Value != IntPtr.Zero ) { UnsafeNativeMethods.UnhookWinEvent(_hHook.Value); _hHook.Value = IntPtr.Zero ; } } #endregion Internal Methods //------------------------------------------------------ // // Private Methods // //------------------------------------------------------ #region Private Methods private void WinEventDefaultProc(int winEventHook, int eventId, IntPtr hwnd, int idObject, int idChild, int eventThread, int eventTime) { WinEventProc(eventId , hwnd); } // Workaround for bug 150666. private void OnDispatcherShutDown(object sender, EventArgs args) { Stop(); } #endregion Private Methods //----------------------------------------------------- // // Private Fields // //------------------------------------------------------ #region Private Fields // min WinEvent. private int _eventMin; // max WinEvent. private int _eventMax; // hook handle private SecurityCriticalDataForSet_hHook; // the callback. private SecurityCriticalDataForSet _winEventProc; // GCHandle to keep the garbage collector from moving things around private GCHandle _gchThis; #endregion Private Fields } } // File provided for Reference Use Only by Microsoft Corporation (c) 2007. // Copyright (c) Microsoft Corporation. All rights reserved.
Link Menu

This book is available now!
Buy at Amazon US or
Buy at Amazon UK
- TextSpan.cs
- LocationUpdates.cs
- HtmlImage.cs
- RuleEngine.cs
- TagMapCollection.cs
- HttpDebugHandler.cs
- ChildTable.cs
- DefaultAsyncDataDispatcher.cs
- WindowsStatusBar.cs
- DataGridViewTopRowAccessibleObject.cs
- ToolboxDataAttribute.cs
- DateTime.cs
- Propagator.JoinPropagator.cs
- FunctionImportMapping.cs
- BoolExpressionVisitors.cs
- Point4DConverter.cs
- wmiprovider.cs
- DeferredReference.cs
- XmlDataSourceNodeDescriptor.cs
- DomainUpDown.cs
- ErrorHandler.cs
- MatchingStyle.cs
- SqlBinder.cs
- InProcStateClientManager.cs
- TypedReference.cs
- BrowserTree.cs
- OptimalTextSource.cs
- RotationValidation.cs
- bindurihelper.cs
- ErrorStyle.cs
- LowerCaseStringConverter.cs
- HtmlValidatorAdapter.cs
- MouseButtonEventArgs.cs
- XPathNodeIterator.cs
- CodeConstructor.cs
- ExceptQueryOperator.cs
- LayoutTable.cs
- WsdlBuildProvider.cs
- SizeAnimationUsingKeyFrames.cs
- XmlHierarchyData.cs
- XmlAtomicValue.cs
- BlobPersonalizationState.cs
- FixedLineResult.cs
- RijndaelManaged.cs
- SpotLight.cs
- AppDomainFactory.cs
- TextTabProperties.cs
- PropertyItemInternal.cs
- PropertyConverter.cs
- WindowsFormsDesignerOptionService.cs
- UTF32Encoding.cs
- CreateUserWizard.cs
- SqlDataSourceDesigner.cs
- ProcessThreadCollection.cs
- CodeBinaryOperatorExpression.cs
- entitydatasourceentitysetnameconverter.cs
- MembershipValidatePasswordEventArgs.cs
- AuthenticationSection.cs
- DrawingImage.cs
- TypedColumnHandler.cs
- Item.cs
- AmbientValueAttribute.cs
- XamlTemplateSerializer.cs
- FileAuthorizationModule.cs
- PrefixQName.cs
- DesignTimeParseData.cs
- DetailsViewInsertEventArgs.cs
- HttpWebRequest.cs
- BinHexEncoder.cs
- DnsCache.cs
- Vector.cs
- CornerRadiusConverter.cs
- WindowsUpDown.cs
- CqlWriter.cs
- CheckPair.cs
- DocumentOrderComparer.cs
- NotCondition.cs
- RadioButton.cs
- XPathNavigator.cs
- MinimizableAttributeTypeConverter.cs
- Transform.cs
- AccessedThroughPropertyAttribute.cs
- MethodToken.cs
- XmlUrlResolver.cs
- updatecommandorderer.cs
- SoapRpcMethodAttribute.cs
- RepeaterItemCollection.cs
- TableCell.cs
- CharStorage.cs
- EditingCoordinator.cs
- StyleCollection.cs
- Track.cs
- Point3DValueSerializer.cs
- FlowPosition.cs
- ProgressBarRenderer.cs
- ObjectPersistData.cs
- AppearanceEditorPart.cs
- NamespaceCollection.cs
- OleDbException.cs
- XmlSchemaValidationException.cs