当前线程不在单线程单元中，因此无法实例化 ActiveX 控件“8856f961-340a-11d0-a96b-00c04fd705a2”

System.Threading.ThreadStart start = new System.Threading.ThreadStart(download);
System.Threading.Thread th = new System.Threading.Thread(start);
th.ApartmentState = System.Threading.ApartmentState.STA;//关键

[STAThread]
static void Main(string[] args)
{
}