Code:
/ 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / wpf / src / Core / CSharp / System / Windows / Media / Imaging / BitmapSourceSafeMILHandle.cs / 1305600 / BitmapSourceSafeMILHandle.cs
//---------------------------------------------------------------------------- // //// Copyright (C) Microsoft Corporation. All rights reserved. // // // // Description: // A sub-class of SafeMILHandle that can estimate size for bitmap // source objects. //--------------------------------------------------------------------------- using System; using System.Diagnostics; using System.Security; using MS.Internal; using MS.Win32; using UnsafeNativeMethods=MS.Win32.PresentationCore.UnsafeNativeMethods; namespace System.Windows.Media.Imaging { ////// Constructor which computes size of the handle and delegates /// to baseclass safe handle. /// internal class BitmapSourceSafeMILHandle : SafeMILHandle { ////// Critical - initializes critical static field (autogenerated ctor) /// TreatAsSafe - sets them to the correct values, it's ok /// [SecurityCritical, SecurityTreatAsSafe] static BitmapSourceSafeMILHandle() { } ////// Use this constructor if the handle isn't ready yet and later /// set the handle with SetHandle. /// ////// Critical: This derives from a class that has a link demand and inheritance demand /// TreatAsSafe: Ok to call constructor /// [SecurityCritical,SecurityTreatAsSafe] internal BitmapSourceSafeMILHandle() : base() { } ////// Use this constructor if the handle exists at construction time. /// SafeMILHandle owns the release of the parameter. /// ////// Critical: It is used to keep memory around /// [SecurityCritical] internal BitmapSourceSafeMILHandle(IntPtr handle) : base() { SetHandle(handle); } ////// Use this constructor if the handle exists at construction time and memory pressure /// should be shared with another SafeMILHandle. /// SafeMILHandle owns the release of the parameter. /// ////// Critical: It is used to keep memory around /// [SecurityCritical] internal BitmapSourceSafeMILHandle(IntPtr handle, SafeMILHandle copyMemoryPressureFrom) : this(handle) { CopyMemoryPressure(copyMemoryPressureFrom); } ////// Calculate the rough size for this handle /// ////// Critical - access unmanaged code /// TreatAsSafe - queries size of the bitmap, safe operation /// /// Attributes are required for UnsafeNativeMethods.* calls /// [SecurityCritical,SecurityTreatAsSafe] internal void CalculateSize() { UpdateEstimatedSize(ComputeEstimatedSize(handle)); } ////// Compute a rough estimate of the size in bytes for the image /// ////// Critical - access unmanaged code and takes an IntPtr /// [SecurityCritical] private static long ComputeEstimatedSize(IntPtr bitmapObject) { long estimatedSize = 0; if (bitmapObject != null && bitmapObject != IntPtr.Zero) { IntPtr wicBitmap; // // QueryInterface for the bitmap source to ensure we are // calling through the right vtable on the pinvoke. // int hr = UnsafeNativeMethods.MILUnknown.QueryInterface( bitmapObject, ref _uuidBitmap, out wicBitmap ); if (hr == HRESULT.S_OK) { Debug.Assert(wicBitmap != IntPtr.Zero); // // The safe handle will release the ref added by the above QI // // There's no need to copy memory pressure. Partly because this SafeMILHandle // is temporary and will be collected after this method returns, partly // because there might no memory pressure calculated yet. // SafeMILHandle bitmapSourceSafeHandle = new SafeMILHandle(wicBitmap); uint pixelWidth = 0; uint pixelHeight = 0; hr = UnsafeNativeMethods.WICBitmapSource.GetSize( bitmapSourceSafeHandle, out pixelWidth, out pixelHeight); if (hr == HRESULT.S_OK) { Guid guidFormat; hr = UnsafeNativeMethods.WICBitmapSource.GetPixelFormat(bitmapSourceSafeHandle, out guidFormat); if (hr == HRESULT.S_OK) { // // Go to long space to avoid overflow and check for overflow // PixelFormat pixelFormat = new PixelFormat(guidFormat); long scanlineSize = (long)pixelWidth * pixelFormat.InternalBitsPerPixel / 8; // // Check that scanlineSize is small enough that we can multiply by pixelHeight // without an overflow. Since pixelHeight is a 32-bit value and we multiply by pixelHeight, // then we can only have a 32-bit scanlineSize. Since we need a sign bit as well, // we need to check that scanlineSize can fit in 30 bits. // if (scanlineSize < 0x40000000) { estimatedSize = pixelHeight * scanlineSize; } } } } } return estimatedSize; } ////// This is overridden to prevent JIT'ing due to new behavior in the CLR. (#708970) /// ////// Critical - Calls into other SecurityCritical code. not treat as safe because /// the caller must validate that the underlying handle is a valid COM object. /// [SecurityCritical] protected override bool ReleaseHandle() { return base.ReleaseHandle(); } ////// Guid for IWICBitmapSource /// ////// Critical - guid used for COM interop, need to be careful not to overwrite /// [SecurityCritical] private static Guid _uuidBitmap = MILGuidData.IID_IWICBitmapSource; } } // 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
- XmlTypeMapping.cs
- SemanticResultValue.cs
- DependencyProperty.cs
- StringKeyFrameCollection.cs
- BlurBitmapEffect.cs
- OdbcEnvironment.cs
- FontSizeConverter.cs
- SimpleLine.cs
- DesignerCategoryAttribute.cs
- WebPartEditorApplyVerb.cs
- PolyLineSegment.cs
- SqlBuilder.cs
- Matrix3DValueSerializer.cs
- SQLMembershipProvider.cs
- DayRenderEvent.cs
- Group.cs
- GenericArgumentsUpdater.cs
- SynchronizingStream.cs
- UrlParameterWriter.cs
- ColorConverter.cs
- InternalResources.cs
- BidOverLoads.cs
- IsolatedStorage.cs
- DynamicValidatorEventArgs.cs
- RubberbandSelector.cs
- CustomWebEventKey.cs
- ContentPresenter.cs
- SubqueryRules.cs
- ListViewInsertionMark.cs
- MetadataCacheItem.cs
- SystemKeyConverter.cs
- ControlBindingsConverter.cs
- PropertyGeneratedEventArgs.cs
- ClientTargetCollection.cs
- ConfigUtil.cs
- KeySplineConverter.cs
- SudsCommon.cs
- VerificationAttribute.cs
- KeyEvent.cs
- Label.cs
- CodeSnippetTypeMember.cs
- DataGridViewDataErrorEventArgs.cs
- MouseEventArgs.cs
- securitycriticaldata.cs
- RoleManagerSection.cs
- ContextMenuStrip.cs
- Walker.cs
- _NativeSSPI.cs
- EntityKeyElement.cs
- CodeMemberMethod.cs
- MsmqSecureHashAlgorithm.cs
- ComplusTypeValidator.cs
- RightNameExpirationInfoPair.cs
- ExtentJoinTreeNode.cs
- DynamicPropertyHolder.cs
- ScriptHandlerFactory.cs
- QEncodedStream.cs
- PageThemeCodeDomTreeGenerator.cs
- SamlConditions.cs
- PropertyGeneratedEventArgs.cs
- GACMembershipCondition.cs
- HTTPNotFoundHandler.cs
- WebControlParameterProxy.cs
- VScrollBar.cs
- WizardDesigner.cs
- SerialPort.cs
- WebResourceAttribute.cs
- SimpleHandlerFactory.cs
- TextParagraphCache.cs
- InkCanvasFeedbackAdorner.cs
- TextEditorDragDrop.cs
- StrokeCollection2.cs
- ScrollEvent.cs
- ProfileSettings.cs
- DSASignatureFormatter.cs
- ConfigurationConverterBase.cs
- AdPostCacheSubstitution.cs
- CustomErrorsSectionWrapper.cs
- CompModSwitches.cs
- ColorConvertedBitmapExtension.cs
- TabItemAutomationPeer.cs
- HMACMD5.cs
- ADRole.cs
- LineUtil.cs
- TransformerInfo.cs
- MarkupProperty.cs
- WCFBuildProvider.cs
- LinkedList.cs
- MultipleCopiesCollection.cs
- TextPattern.cs
- SecurityDescriptor.cs
- TargetInvocationException.cs
- PageBuildProvider.cs
- WmlCommandAdapter.cs
- DesignerVerb.cs
- XmlWellformedWriter.cs
- DataGridLinkButton.cs
- WebPartEditorCancelVerb.cs
- OracleRowUpdatingEventArgs.cs
- CachedPathData.cs