使应用程序只运行单个实例（C#）

代码如下：（在类中）

public partial class AppSingleton : Form
    {
        public AppSingleton()
        {
            InitializeComponent();
        }
         static Mutex m_Mutex;

        public static void Run()
        {
            if (IsFirstInstance()) {
                 Application.ApplicationExit += new EventHandler(OnExit);
                Application .Run();
            }

         }
        public static void Run (ApplicationContext context)
        {
            if (IsFirstInstance()) {
                Application.ApplicationExit += new EventHandler(OnExit);
                Application.Run(context );
            }
        }
        public static void Run(Form mainForm)
        {
             if (IsFirstInstance()) {

                Application.ApplicationExit += new EventHandler(OnExit);

                Application.Run(mainForm);


            } else {

                MessageBox.Show("应用程序已启动,请在任务管理中关闭后再启动！" , "系统提示", MessageBoxButtons.OK, MessageBoxIcon.Warning);
            }
        }
         static bool IsFirstInstance()
        {
            m_Mutex = new Mutex(false, "SingletonApp Mutext" );
            bool owned = false;
            owned = m_Mutex .WaitOne(TimeSpan.Zero, false );
            return owned;
        }
        static void OnExit(object sender, EventArgs args )
        {
            m_Mutex.ReleaseMutex ();
            m_Mutex.Close();
         }
    }
主程序中（main）需要做如下修改：

AppSingleton.Run(new AppSingleton());
//Application.Run(new AppSingleton());