Task_Dispose_NotCompleted error but i don't know why

Question

today i was faced with a very strange error regarding Tasks. In my code i tried to use the using statement this way:

protected MyClass() {
    using(var initTask = new Task(() => Init())) {
        initTask.ContinueWith(result => InitCompletedCallBack(result));
        initTask.Start();
    }
}

protected virtual void Init() {}

private void InitCompletedCallBack(AsyncResult result) {
    // Stuff
}

When i execute this code i get an Task_Dispose_NotComplete error. The error occures when InitCompletedCallBack has finished.

While trying arounf i changed the using to this:

using(var initTask = new Task(() => Init())) {
    initTask.ContinueWith(result => InitCompletedCallBack(result));
    initTask.Start();
    Thread.Sleep(1000);
}

And that worked. However, this piece of code will be executed several times when the application starts and thus freezes the application for approximatelly 15-20 seconds. But it shows that something (inside the task?) needs at least one second to finish.

Any ideas what causes this behavior?

Thanks in advance.

Edit When i set the time to wait to 100ms, the error occures. The first lines of the StackTrace are:

bei System.Threading.Tasks.Task.Dispose(Boolean disposing)
bei System.Threading.Tasks.Task.Dispose()
bei MyClass..ctor() in c:\Path\to\source\MyClass.cs:line 33.

Line 33 is the closing bracket of the using block.

Answer 1

Any ideas what causes this behavior?

Your code causes this behavior. You dispose a task that is not yet done. Why do you want to dispose it where you dispose it? Does the using-block make sense where you put it?

Do not dispose a task that you still rely on. Remove the using block.