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    copied!<p>Honestly? Don't use <code>BackgroundWorker</code>. Use TPL manually, <a href="http://msdn.microsoft.com/en-us/library/hh228603.aspx" rel="nofollow">TPL Dataflow</a> or even <a href="http://msdn.microsoft.com/en-us/data/gg577609.aspx" rel="nofollow">Reactive Extensions</a> (Rx) if you want this kind of control.</p> <p>Personally I would use TPL Dataflow and I would setup an <code>TransformBlock&lt;MyObject, MyObject&gt;</code> which you configure with a <code>MaxDegreeOfParallelism</code> that makes sense for you (e.g. you want to process 20 at a time) and then link that back to a UI updating <code>ActionBlock&lt;MyObject&gt;</code> that is configured to run on the UI (<code>Dispatcher</code>) thread. Such code would look something like this...</p> <p><em><strong>Somewhere in your initialization logic, possibly as part of Window constructor (NOTE: must be executed on the main Dispatcher thread to work correctly)</em></strong></p> <pre><code>TransformBlock&lt;MyObject, MyObject&gt; myProcessingBlock = new ActionBlock&lt;MyObject, MyObject&gt;( myObject =&gt; { // ... perform your processing of this object here ... return myObject; }, new ExecutionDataflowBlockOptions { MaxDegreeOfParallelism = 20 }); ActionBlock&lt;MyObject&gt; myUINotificationBlock = new ActionBlock&lt;MyObject&gt;( myObject =&gt; { // ... update the UI details for this data here ... }, new ExecutionDataflowBlockOptions { TaskScheduler = TaskScheduler.FromCurrentSynchronizationContext() // must be executed on the Dispatcher block! }); myProcessingBlock.LinkTo(myUINotificationBlock); </code></pre> <p><em><strong>And this is how you would post new work to it:</em></strong></p> <pre><code>MyObject someObjectToProcess = GetSomeObjectToProcess(...); myProcessingBlock.Post(someObjectToProcess); </code></pre> <p>The rest is all handled for you by the magic of the TPL Dataflow Library. Just declare it and set it free. TPL Dataflow even supports <code>async</code> methods, so if you know you're going to be making web service calls you can just use the <code>async</code> keyword on the method you define for the <code>TransformBlock&lt;MyObject, MyObject&gt;</code> like so:</p> <pre><code>TransformBlock&lt;MyObject, MyObject&gt; myProcessingBlock = new ActionBlock&lt;MyObject, MyObject&gt;( async myObject =&gt; { HttpClient someHttpClient = new HttpClient(); HttpResponseMessage responseMessage = await someHttpClient.PostAsync(..., ...); return myObject; }, new ExecutionDataflowBlockOptions { MaxDegreeOfParallelism = 20 }); </code></pre> <p>This way you won't even block a CPU thread while the HTTP network call is outstanding which is even more full of win.</p>
 

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