Code:
/ DotNET / DotNET / 8.0 / untmp / whidbey / REDBITS / ndp / fx / src / CompMod / System / ComponentModel / BackgroundWorker.cs / 1 / BackgroundWorker.cs
//------------------------------------------------------------------------------ //// Copyright (c) Microsoft Corporation. All rights reserved. // //----------------------------------------------------------------------------- namespace System.ComponentModel { using System.ComponentModel.Design.Serialization; using System.Diagnostics; using System.Security.Permissions; using System.Threading; [ SRDescription(SR.BackgroundWorker_Desc), DefaultEvent("DoWork"), HostProtection(SharedState = true) ] public class BackgroundWorker : Component { // Private statics private static readonly object doWorkKey = new object(); private static readonly object runWorkerCompletedKey = new object(); private static readonly object progressChangedKey = new object(); // Private instance members private bool canCancelWorker = false; private bool workerReportsProgress = false; private bool cancellationPending = false; private bool isRunning = false; private AsyncOperation asyncOperation = null; private readonly WorkerThreadStartDelegate threadStart; private readonly SendOrPostCallback operationCompleted; private readonly SendOrPostCallback progressReporter; public BackgroundWorker() { threadStart = new WorkerThreadStartDelegate(WorkerThreadStart); operationCompleted = new SendOrPostCallback(AsyncOperationCompleted); progressReporter = new SendOrPostCallback(ProgressReporter); } private void AsyncOperationCompleted(object arg) { isRunning = false; cancellationPending = false; OnRunWorkerCompleted((RunWorkerCompletedEventArgs)arg); } [ Browsable(false), SRDescription(SR.BackgroundWorker_CancellationPending) ] public bool CancellationPending { get { return cancellationPending; } } public void CancelAsync() { if (!WorkerSupportsCancellation) { throw new InvalidOperationException(SR.GetString(SR.BackgroundWorker_WorkerDoesntSupportCancellation)); } cancellationPending = true; } [ SRCategory(SR.PropertyCategoryAsynchronous), SRDescription(SR.BackgroundWorker_DoWork) ] public event DoWorkEventHandler DoWork { add { this.Events.AddHandler(doWorkKey, value); } remove { this.Events.RemoveHandler(doWorkKey, value); } } ///[ Browsable(false), SRDescription(SR.BackgroundWorker_IsBusy) ] public bool IsBusy { get { return isRunning; } } /// protected virtual void OnDoWork(DoWorkEventArgs e) { DoWorkEventHandler handler = (DoWorkEventHandler)(Events[doWorkKey]); if (handler != null) { handler(this, e); } } /// protected virtual void OnRunWorkerCompleted(RunWorkerCompletedEventArgs e) { RunWorkerCompletedEventHandler handler = (RunWorkerCompletedEventHandler)(Events[runWorkerCompletedKey]); if (handler != null) { handler(this, e); } } protected virtual void OnProgressChanged(ProgressChangedEventArgs e) { ProgressChangedEventHandler handler = (ProgressChangedEventHandler)(Events[progressChangedKey]); if (handler != null) { handler(this, e); } } [ SRCategory(SR.PropertyCategoryAsynchronous), SRDescription(SR.BackgroundWorker_ProgressChanged) ] public event ProgressChangedEventHandler ProgressChanged { add { this.Events.AddHandler(progressChangedKey, value); } remove { this.Events.RemoveHandler(progressChangedKey, value); } } // Gets invoked through the AsyncOperation on the proper thread. private void ProgressReporter(object arg) { OnProgressChanged((ProgressChangedEventArgs)arg); } // Cause progress update to be posted through current AsyncOperation. public void ReportProgress(int percentProgress) { ReportProgress(percentProgress, null); } // Cause progress update to be posted through current AsyncOperation. public void ReportProgress(int percentProgress, object userState) { if (!WorkerReportsProgress) { throw new InvalidOperationException(SR.GetString(SR.BackgroundWorker_WorkerDoesntReportProgress)); } ProgressChangedEventArgs args = new ProgressChangedEventArgs(percentProgress, userState); if (asyncOperation != null) { asyncOperation.Post(progressReporter, args); } else { progressReporter(args); } } public void RunWorkerAsync() { RunWorkerAsync(null); } public void RunWorkerAsync(object argument) { if (isRunning) { throw new InvalidOperationException(SR.GetString(SR.BackgroundWorker_WorkerAlreadyRunning)); } isRunning = true; cancellationPending = false; asyncOperation = AsyncOperationManager.CreateOperation(null); threadStart.BeginInvoke(argument, null, null); } [ SRCategory(SR.PropertyCategoryAsynchronous), SRDescription(SR.BackgroundWorker_RunWorkerCompleted) ] public event RunWorkerCompletedEventHandler RunWorkerCompleted { add { this.Events.AddHandler(runWorkerCompletedKey, value); } remove { this.Events.RemoveHandler(runWorkerCompletedKey, value); } } [ SRCategory(SR.PropertyCategoryAsynchronous), SRDescription(SR.BackgroundWorker_WorkerReportsProgress), DefaultValue(false) ] public bool WorkerReportsProgress { get { return workerReportsProgress; } set { workerReportsProgress = value; } } [ SRCategory(SR.PropertyCategoryAsynchronous), SRDescription(SR.BackgroundWorker_WorkerSupportsCancellation), DefaultValue(false) ] public bool WorkerSupportsCancellation { get { return canCancelWorker; } set { canCancelWorker = value; } } private delegate void WorkerThreadStartDelegate(object argument); private void WorkerThreadStart(object argument) { object workerResult = null; Exception error = null; bool cancelled = false; try { DoWorkEventArgs doWorkArgs = new DoWorkEventArgs(argument); OnDoWork(doWorkArgs); if (doWorkArgs.Cancel) { cancelled = true; } else { workerResult = doWorkArgs.Result; } } catch (Exception exception) { error = exception; } RunWorkerCompletedEventArgs e = new RunWorkerCompletedEventArgs(workerResult, error, cancelled); asyncOperation.PostOperationCompleted(operationCompleted, e); } } }
Link Menu
This book is available now!
Buy at Amazon US or
Buy at Amazon UK
- XPathNavigator.cs
- PrinterUnitConvert.cs
- PropertyDescriptor.cs
- DataGridViewHeaderCell.cs
- SqlCommand.cs
- SQLRoleProvider.cs
- QueryContinueDragEventArgs.cs
- RunClient.cs
- Tag.cs
- PaintEvent.cs
- DbgUtil.cs
- pingexception.cs
- MetabaseServerConfig.cs
- UndoEngine.cs
- DrawingGroup.cs
- ExpressionVisitor.cs
- BitArray.cs
- Accessible.cs
- CorrelationHandle.cs
- TracingConnectionListener.cs
- DataRow.cs
- ArrayList.cs
- FormsAuthenticationConfiguration.cs
- XmlSchemaAttributeGroupRef.cs
- FunctionImportElement.cs
- ContentOperations.cs
- InstanceCreationEditor.cs
- UriTemplateEquivalenceComparer.cs
- BamlRecordWriter.cs
- LocalizableAttribute.cs
- Annotation.cs
- CompressStream.cs
- LayoutManager.cs
- RawTextInputReport.cs
- SqlDependencyListener.cs
- FormClosingEvent.cs
- EditBehavior.cs
- ToolStripMenuItemCodeDomSerializer.cs
- TabControlCancelEvent.cs
- DataGridViewCellCollection.cs
- PopupControlService.cs
- ApplicationProxyInternal.cs
- InstanceStoreQueryResult.cs
- PageThemeParser.cs
- ObjectNotFoundException.cs
- Column.cs
- ColorConvertedBitmapExtension.cs
- ObjectSet.cs
- SourceFilter.cs
- IISUnsafeMethods.cs
- DataTableNewRowEvent.cs
- ItemAutomationPeer.cs
- CrossSiteScriptingValidation.cs
- PointAnimationClockResource.cs
- IconConverter.cs
- EncodingDataItem.cs
- NameHandler.cs
- TransformProviderWrapper.cs
- RequestNavigateEventArgs.cs
- CompleteWizardStep.cs
- HostedNamedPipeTransportManager.cs
- AxisAngleRotation3D.cs
- Helpers.cs
- TemplateXamlParser.cs
- SchemaImporter.cs
- ExpressionReplacer.cs
- SqlDataSourceSelectingEventArgs.cs
- PriorityQueue.cs
- ObjectDataSourceStatusEventArgs.cs
- SimplePropertyEntry.cs
- TemplateControlCodeDomTreeGenerator.cs
- DbConnectionOptions.cs
- SqlFacetAttribute.cs
- TextSearch.cs
- StylusTip.cs
- XmlHierarchicalDataSourceView.cs
- _AutoWebProxyScriptHelper.cs
- InternalControlCollection.cs
- FacetValues.cs
- DataGridViewTopRowAccessibleObject.cs
- SettingsPropertyNotFoundException.cs
- CapabilitiesSection.cs
- ipaddressinformationcollection.cs
- MessageEventSubscriptionService.cs
- SoapHttpTransportImporter.cs
- ManualResetEventSlim.cs
- WindowsAuthenticationModule.cs
- UrlMappingCollection.cs
- LinkDescriptor.cs
- UTF8Encoding.cs
- StringExpressionSet.cs
- XmlExtensionFunction.cs
- TraceContext.cs
- NodeFunctions.cs
- Typography.cs
- BridgeDataReader.cs
- FormsAuthenticationEventArgs.cs
- LocatorBase.cs
- AttachedPropertyBrowsableAttribute.cs
- Bidi.cs