Question

I am using a backgroundworker that can have n instances. Problem is the DoWork method (that has the ‘sender’ parameter which is the BackgroundWorker) calls other code that produces a callback – thus i dont have the sender.

How can i determine the BackgroundWorker that the current code is running under?

ex:

private void SetupThread()
{
BackgroundWorker bw = new BackgroundWorker();
bw.DoWork += new DoWorkEventHandler(DoTheWork);
}


private void DoTheWork(object sender, System.ComponentModel.DoWorkEventArgs e)
{

    // I know that sender here can be converted, but thats no good for me
    MyClass.DoSomething(); // This will produce a callback(event) from MyClass
}

private void MethodCalledFromEventCallback()
{
   // Here is where the actual work is being done.  I need to determine which
   // instance of the Backgroundworker is calling it so that i can use the         
   // UpdateProgress method

  // I cannot do this :-(  (BackgroundWorker)System.Threading.Thread.CurrentThread;

}

Im probably just overlooking something (unless threadpool is in order 🙁 )

Im sure this is easily doable with the BackgroundWorker … any ideas?

---

edit

I caused some confusion in my description, here are some more facts 🙂
1.) I already call the bw.RunWorkerAsync()
2.) The class that invokes the event MethodCalledFromEventCallback has no knowledge of the background thread
3.) I cannot (due to design requirements) include the Backgroundworker as a parameter

Thanks 🙂

Answer 1

As far as I know the best you could probably get away with using a background worker is (assuming the constrants you’ve mentioned so far):

private void SetupThread()
{
    BackgroundWorker bw = new BackgroundWorker();
    // Assuming you need sender and e. If not, you can just send bw
    bw.DoWork += new DoWorkEventHandler(DoTheWork);
}

private void DoTheWork(object sender, System.ComponentModel.DoWorkEventArgs e)
{
    MyClass.Callback = () => 
        {
            ((BackgroundWorker)bw).UpdateProgress(/*send your update here*/);
            MethodCalledFromEventCallback();
        };

    MyClass.DoSomething(); // This will produce a callback(event) from MyClass
}

private void MethodCalledFromEventCallback() 
{ 
    // You've already sent an update by this point, so no background parameter required
}