Implementing callback mechanism as async/await pattern in C# -

how transform following callback-driven code async/await pattern properly:

public class devicewrapper {  // external device provides real time stream of data  private internaldevice device = new internaldevice();  private list<int> accumulationbuffer = new list<int>();   public void startreceiving()  {      // following callback invocations might synchronized main      // ui message pump, particular window message pump      // or other way      device.synchronization = synchronization.ui;      device.dataavailable += dataavailablehandler;      device.receivingstoppedorerroroccured += stophandler;      device.start();  }   private void dataavailablehandler(object sender, dataeventargs e)  {      // filter data e.data , accumulate accumulationbuffer field.      // if certail condition met, signal pending task (if there any)      //as complete return awaiting caller accumulationbuffer or perhaps temporary buffer created accumulationbuffer      // in order make available caller.      // handle requested cancellation.  }   public task<byte[]> getdata(cancellationtoken token)  {      // create task returning data filtered , accumulated in dataavailablehandler   } } // usage: async void test() {  devicewrapper w = new devicewrapper();  w.startreceiving();  while(true)  {   byte[] filtereddata = await w.getdata(cancellationtoken.null);   use(filtereddata);  } } 

i have sought inspiration solve reading .net streamreader class source, made me more confused.

thank experts advice!

you're looking taskcompletionsource<byte[]>. approximation of like:

public task<byte[]> getdata(cancellationtoken token) {       cancellationtoken.throwifcancellationrequested;        var tcs = new taskcompletionsource<byte[]>();       dataeventhandler datahandler = null;       datahandler = (o, e) =>        {           device.dataavailable -= datahandler;           tcs.setresult(e.data);       }        stopeventhandler stophandler = null;       stophandler = (os, se) =>       {             device.receivingstoppedorerroroccured -= stophandler;             // assuming stop handler has sort of error property.             tcs.setexception(se.exception);       }        device.dataavailable += datahandler;       device.receivingstoppedorerroroccured += stophandler;       device.start();        return tcs.task; }