main() 前面有 [STAThread]             Thread.CurrentThread.ApartmentState = ApartmentState.STA;            Debug.WriteLine(Thread.CurrentThread.ApartmentState);            Thread.CurrentThread.SetApartmentState(ApartmentState.STA);            Debug.WriteLine(Thread.CurrentThread.GetApartmentState());Thread.CurrentThread.ApartmentState = ApartmentState.STA;           Debug.WriteLine(Thread.CurrentThread.ApartmentState);// 這里還是顯示是 MTAThread.CurrentThread.SetApartmentState(ApartmentState.STA);          // 這里會出異常：Failed to set the specified COM apartment state.Debug.WriteLine(Thread.CurrentThread.GetApartmentState());// 把上面那行去掉，這里還是顯示 MTAif (openFileDialog.ShowDialog() == DialogResult.OK)// 異常：Current thread must be set to single thread apartment (STA) mode before OLE calls can be made. Ensure that your Main function has STAThreadAttribute marked on it. This exception is only raised if a debugger is attached to the process.這是為什么呢？