Best and simplest: using(var d = Dispatcher.DisableProcessing()) { /* your work… Use dispacher.begininvoke… */ } Or IDisposable d; try { d = Dispatcher.DisableProcessing(); /* your work… Use dispacher.begininvoke… */ } finally { d.Dispose(); }
The exception is not passed back to the calling thread. If you want it to be, you can add a catch block and figure out a way to signal the calling thread. If the calling thread is a WinForms or WPF UI thread, you can use the SynchronizationContext class to pass a call to the … Read more
You seem to have it back to front. Rather than the BackgroundWorker handling the ProgressBar updates, use the BGW to do the time consuming work. Then at intervals you can provide updates for the ProgressBar/Form using the built-in ReportProgress method. Normally, you cannot (directly) access UI controls, like a ProgressBar, from a thread other than … Read more
Maybe you can use a manualresetevent like this, I didn’t debug this but worth a shot. If it works you won’t be having the thread spin its wheels while it’s waiting ManualResetEvent run = new ManualResetEvent(true); private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e) { while(run.WaitOne()) { //Kill zombies } } private void War() { run.Set(); } … Read more
You need to break your DoWork method down into reportable progress and then call ReportProgress. Take for example the following: private void Something_DoWork(object sender, DoWorkEventArgs e) { // If possible, establish how much there is to do int totalSteps = EstablishWorkload(); for ( int i=0; i<totalSteps; i++) { // Do something… // Report progress, hint: … Read more
The main difference between the Dispatcher and other threading methods is that the Dispatcher is not actually multi-threaded. The Dispatcher governs the controls, which need a single thread to function properly; the BeginInvoke method of the Dispatcher queues events for later execution (depending on priority etc.), but still on the same thread. BackgroundWorker on the … Read more
You need something like this: public delegate void ProgressChangeDelegate(double Percentage, ref bool Cancel); public delegate void Completedelegate(); class CustomFileCopier { public CustomFileCopier(string Source, string Dest) { this.SourceFilePath = Source; this.DestFilePath = Dest; OnProgressChanged += delegate { }; OnComplete += delegate { }; } public void Copy() { byte[] buffer = new byte[1024 * 1024]; // … Read more
The main problems (set Option Strict On to find more): You can’t access the UI objects from a thread different than the UI Thread. The error you receive is: Cross-thread operation not valid:Control lblFileSizeD accessed from a thread other than the thread it was created on Then, the same error for lblDownloadedBytesD. Also, you are … Read more
This article explains everything you need clearly. Here are the minimum steps in using BackgroundWorker: Instantiate BackgroundWorker and handle the DoWork event. Call RunWorkerAsync, optionally with an object argument. This then sets it in motion. Any argument passed to RunWorkerAsync will be forwarded to DoWork’s event handler, via the event argument’s Argument property. Here’s an … Read more
If you’re using ADO.NET and SQL data provider, take a look at SqlCommand.Cancel method. That does what you’re looking for. However, it tries to cancel and the cancellation may take time. Basically, it’s up to SQL Server to decide when to grant your cancellation request. When the query is cancelled, you should get a SqlException … Read more