Code:
/ 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / WinForms / Managed / System / WinForms / PaintEvent.cs / 1305376 / PaintEvent.cs
//------------------------------------------------------------------------------ //// Copyright (c) Microsoft Corporation. All rights reserved. // //----------------------------------------------------------------------------- namespace System.Windows.Forms { using Microsoft.Win32; using System; using System.ComponentModel; using System.Diagnostics; using System.Drawing; using System.Windows.Forms.Internal; using System.Drawing.Drawing2D; using System.Runtime.InteropServices; ////// /// // NOTE: Please keep this class consistent with PrintPageEventArgs. public class PaintEventArgs : EventArgs, IDisposable { ////// Provides data for the ////// event. /// /// Graphics object with which painting should be done. /// private Graphics graphics = null; // See ResetGraphics() private GraphicsState savedGraphicsState = null; ////// DC (Display context) for obtaining the graphics object. Used to delay getting the graphics /// object until absolutely necessary (for perf reasons) /// private readonly IntPtr dc = IntPtr.Zero; IntPtr oldPal = IntPtr.Zero; ////// Rectangle into which all painting should be done. /// private readonly Rectangle clipRect; //private Control paletteSource; #if DEBUG static readonly TraceSwitch PaintEventFinalizationSwitch = new TraceSwitch("PaintEventFinalization", "Tracks the creation and finalization of PaintEvent objects"); internal static string GetAllocationStack() { if (PaintEventFinalizationSwitch.TraceVerbose) { return Environment.StackTrace; } else { return "Enabled 'PaintEventFinalization' trace switch to see stack of allocation"; } } private string AllocationSite = PaintEventArgs.GetAllocationStack(); #endif ////// /// public PaintEventArgs(Graphics graphics, Rectangle clipRect) { if( graphics == null ){ throw new ArgumentNullException("graphics"); } this.graphics = graphics; this.clipRect = clipRect; } // Internal version of constructor for performance // We try to avoid getting the graphics object until needed internal PaintEventArgs(IntPtr dc, Rectangle clipRect) { Debug.Assert(dc != IntPtr.Zero, "dc is not initialized."); this.dc = dc; this.clipRect = clipRect; } ////// Initializes a new instance of the ///class with the specified graphics and /// clipping rectangle. /// ~PaintEventArgs() { Dispose(false); } /// /// /// public Rectangle ClipRectangle { get { return clipRect; } } ////// Gets the /// rectangle in which to paint. /// ////// Gets the HDC this paint event is connected to. If there is no associated /// HDC, or the GDI+ Graphics object has been created (meaning GDI+ now owns the /// HDC), 0 is returned. /// /// internal IntPtr HDC { get { if (graphics == null) return dc; else return IntPtr.Zero; } } ////// /// public System.Drawing.Graphics Graphics { get { if (graphics == null && dc != IntPtr.Zero) { oldPal = Control.SetUpPalette(dc, false /*force*/, false /*realize*/); graphics = Graphics.FromHdcInternal(dc); graphics.PageUnit = GraphicsUnit.Pixel; savedGraphicsState = graphics.Save(); // See ResetGraphics() below } return graphics; } } // We want a way to dispose the GDI+ Graphics, but we don't want to create one // simply to dispose it // cpr: should be internal ////// Gets the ////// object used to /// paint. /// /// /// public void Dispose() { Dispose(true); GC.SuppressFinalize(this); } ////// Disposes /// of the resources (other than memory) used by the ///. /// protected virtual void Dispose(bool disposing) { #if DEBUG Debug.Assert(disposing, "PaintEvent object should be explicitly disposed. Potential GDI multithreading lock issue. Allocation stack:\r\n" + AllocationSite); #endif if (disposing) { //only dispose the graphics object if we created it via the dc. if (graphics != null && dc != IntPtr.Zero) { graphics.Dispose(); } } if (oldPal != IntPtr.Zero && dc != IntPtr.Zero) { SafeNativeMethods.SelectPalette(new HandleRef(this, dc), new HandleRef(this, oldPal), 0); oldPal = IntPtr.Zero; } } // If ControlStyles.AllPaintingInWmPaint, we call this method // after OnPaintBackground so it appears to OnPaint that it's getting a fresh // Graphics. We want to make sure AllPaintingInWmPaint is purely an optimization, // and doesn't change behavior, so we need to make sure any clipping regions established // in OnPaintBackground don't apply to OnPaint. See ASURT 44682. internal void ResetGraphics() { if (graphics != null) { Debug.Assert(dc == IntPtr.Zero || savedGraphicsState != null, "Called ResetGraphics more than once?"); if (savedGraphicsState != null) { graphics.Restore(savedGraphicsState); savedGraphicsState = null; } } } } } // File provided for Reference Use Only by Microsoft Corporation (c) 2007.
Link Menu
This book is available now!
Buy at Amazon US or
Buy at Amazon UK
- TextContainerChangedEventArgs.cs
- securitycriticaldata.cs
- _emptywebproxy.cs
- CompositeControl.cs
- DoubleLink.cs
- HebrewCalendar.cs
- EntryIndex.cs
- UserPreferenceChangingEventArgs.cs
- AvTraceFormat.cs
- HttpResponse.cs
- FormViewPagerRow.cs
- HostExecutionContextManager.cs
- NegotiateStream.cs
- FixedNode.cs
- StringToken.cs
- WaitHandleCannotBeOpenedException.cs
- SqlMethodAttribute.cs
- XPathAncestorQuery.cs
- StorageEntitySetMapping.cs
- TextFormatterHost.cs
- AlignmentYValidation.cs
- FocusWithinProperty.cs
- TokenBasedSet.cs
- WebPartCatalogCloseVerb.cs
- TailCallAnalyzer.cs
- FilterEventArgs.cs
- DocComment.cs
- WebBrowserNavigatedEventHandler.cs
- SchemaNames.cs
- NullableIntSumAggregationOperator.cs
- TraceLog.cs
- DesignBindingPropertyDescriptor.cs
- ScopedMessagePartSpecification.cs
- ValuePattern.cs
- TrackingServices.cs
- ProgressChangedEventArgs.cs
- NonBatchDirectoryCompiler.cs
- QueryStringParameter.cs
- ControlBuilderAttribute.cs
- InlineUIContainer.cs
- BinaryObjectInfo.cs
- XmlBufferReader.cs
- TextSerializer.cs
- SetState.cs
- SelectionRangeConverter.cs
- EventSinkHelperWriter.cs
- WebPartHelpVerb.cs
- OleDbTransaction.cs
- DataGridViewRowErrorTextNeededEventArgs.cs
- BlockExpression.cs
- TypeUnloadedException.cs
- WebPartDisplayModeCancelEventArgs.cs
- DynamicMethod.cs
- LostFocusEventManager.cs
- IInstanceTable.cs
- httpstaticobjectscollection.cs
- StrokeRenderer.cs
- DataGridParentRows.cs
- ListControlBoundActionList.cs
- SourceFileBuildProvider.cs
- AsyncOperation.cs
- SetStateDesigner.cs
- MergeFilterQuery.cs
- EventKeyword.cs
- OleDbRowUpdatingEvent.cs
- ApplyTemplatesAction.cs
- XpsFilter.cs
- ExeConfigurationFileMap.cs
- ValidationResult.cs
- OutKeywords.cs
- SizeConverter.cs
- ValidationResults.cs
- WebPartVerbCollection.cs
- DbConnectionFactory.cs
- smtppermission.cs
- DataListCommandEventArgs.cs
- TCPClient.cs
- SiteMapNodeItemEventArgs.cs
- JsonWriterDelegator.cs
- DateTimeOffsetAdapter.cs
- FixedSOMLineCollection.cs
- EventManager.cs
- FileSystemWatcher.cs
- Model3DCollection.cs
- UiaCoreTypesApi.cs
- UdpDiscoveryMessageFilter.cs
- SpecularMaterial.cs
- Int32Collection.cs
- EncodingFallbackAwareXmlTextWriter.cs
- Size3D.cs
- ImageSource.cs
- CodeArrayCreateExpression.cs
- ProtocolsSection.cs
- GetCardDetailsRequest.cs
- ListParagraph.cs
- IPEndPoint.cs
- MediaPlayer.cs
- ArgIterator.cs
- GridViewDeletedEventArgs.cs
- FormsAuthenticationEventArgs.cs