internal void Start(LegacyPageAsyncTaskManager manager, Object source, EventArgs args) { Debug.Assert(!_started); _taskManager = manager; _completionCallback = new AsyncCallback(this.OnAsyncTaskCompletion); _started = true; Debug.Trace("Async", "Start task"); try { IAsyncResult ar = _beginHandler(source, args, _completionCallback, _state); if (ar == null) { throw new InvalidOperationException(SR.GetString(SR.Async_null_asyncresult)); } if (_asyncResult == null) { // _asyncResult could be not null if already completed _asyncResult = ar; } } catch (Exception e) { Debug.Trace("Async", "Task failed to start"); _error = e; _completed = true; _completedSynchronously = true; _taskManager.TaskCompleted(true /*onCallerThread*/); // notify TaskManager // it is ok to say false (onCallerThread) above because this kind of // error completion will never be the last in ResumeTasks() } }
internal void Start(LegacyPageAsyncTaskManager manager, Object source, EventArgs args) { Debug.Assert(!_started); _taskManager = manager; _completionCallback = new AsyncCallback(this.OnAsyncTaskCompletion); _started = true; Debug.Trace("Async", "Start task"); try { IAsyncResult ar = _beginHandler(source, args, _completionCallback, _state); if (ar == null) { throw new InvalidOperationException(SR.GetString(SR.Async_null_asyncresult)); } if (_asyncResult == null) { // _asyncResult could be not null if already completed _asyncResult = ar; } } catch (Exception e) { Debug.Trace("Async", "Task failed to start"); _error = e; _completed = true; _completedSynchronously = true; _taskManager.TaskCompleted(true /*onCallerThread*/); // notify TaskManager // it is ok to say false (onCallerThread) above because this kind of // error completion will never be the last in ResumeTasks() } }