public void UpdateTime(string start, string end) { if (StartTimeLabel.InvokeRequired) { var d = new SafeCallDelegateTitle2(UpdateTime); IAsyncResult ar2 = this.BeginInvoke(d, new object[] { start, end }); // ar2.AsyncWaitHandle.WaitOne(); } else { if (StartTimeLabel.Text != start) { StartTimeLabel.Text = start; EndTimeLabel.Text = end; SeekBar.Invalidate(); } } }