方案一:
//判断是否已经存在一个exe
是要写在main函数里面的
[STAThread]
static void Main()
{
bool createdNew;
Mutex m = new Mutex(true, "yourexe", out createdNew);
if (! createdNew)
{
MessageBox.Show("Only one exe is allowed at a time.");
return;
}
Application.Run(new Start());
GC.KeepAlive(m);
}