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POUsing Tasks with conditional continuations
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copied!<p>I'm a little confused about how to use Tasks with conditional Continuations.</p> <p>If I have a task, and then I want to continue with a tasks that handle success and error, and then wait on those to complete. </p> <pre><code>void FunctionThrows() {throw new Exception("faulted");} static void MyTest() { var taskThrows = Task.Factory.StartNew(() => FunctionThrows()); var onSuccess = taskThrows.ContinueWith( prev => Console.WriteLine("success"), TaskContinuationOptions.OnlyOnRanToCompleted); var onError = taskThrows.ContinueWith( prev => Console.WriteLine(prev.Exception), TaskContinuationOptions.OnlyOnFaulted); //so far, so good //this throws because onSuccess was cancelled before it was started Task.WaitAll(onSuccess, onError); } </code></pre> <p>Is this the preferred way of doing task success/failure branching? Also, how am I supposed to join all these tasks, suppose I've created a long line of continuations, each having their own error handling.</p> <pre><code> //for example var task1 = Task.Factory.StartNew(() => ...) var task1Error = task1.ContinueWith( //on faulted var task2 = task1.ContinueWith( //on success var task2Error = task2.ContinueWith( //on faulted var task3 = task2.ContinueWith( //on success //etc </code></pre> <p>Calling <code>WaitAll</code> on these invariably throws, because some of the continuations will be cancelled due to the <code>TaskContinuationOptions</code>, and calling <code>Wait</code> on a cancelled task throws. How do I join these without getting the "A task was cancelled" exception"?</p>

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