winform程序是否重复运行

bool ret;

System.Threading.Mutex m = new System.Threading.Mutex(true, Application.ProductName, out ret);

if (ret)

{

Application.EnableVisualStyles();

Application.SetCompatibleTextRenderingDefault(false);

//System.Windows.Forms.Application.DoEvents();

Application.Run(new Login());

m.ReleaseMutex();

}

else

{

MessageBox.Show("程序已经在运行，不可重复运行!", "错误", MessageBoxButtons.OK, MessageBoxIcon.Error);

Application.Exit();

}