创建单例winform应用程序

方法1： using System; using System.Collections.Generic; using System.Linq; using System.Windows.Forms; using System.Threading; using System.Reflection; static class Program { private static Mutex singleton; /// <summary> /// The main entry point for the application. /// </summary> [STAThread] static void Main() { Application.EnableVisualStyles(); Application.SetCompatibleTextRenderingDefault(false); bool has=Check() ; if (has) { Form form = new Form1(); form.FormClosed += new FormClosedEventHandler(form_FormClosed); Application.Run(form); } else { MessageBox.Show("程序已启动"); } } static void form_FormClosed(object sender, FormClosedEventArgs e) { if (singleton != null) { singleton.Close(); } } private static bool Check() { bool has=false; singleton=new Mutex(false,Assembly.GetExecutingAssembly().FullName,out has); // Assembly.GetExecutingAssembly().GetModules()[0].FullyQualifiedName; return has; } } }

方法2：

static class Program { /// <summary> /// 应用程序的主入口点。 /// </summary> [STAThread] static void Main() { Process instance = RunningInstance(); //Get the running instance. if (instance == null) { //There isn 't another instance, show our form. Application.EnableVisualStyles(); Application.SetCompatibleTextRenderingDefault(false); Application.Run(new MainForm()); } else { Message.WriteErrMsg("程序已运行，请勿再次运行!"); } } public static Process RunningInstance() { Process current = Process.GetCurrentProcess(); Process[] processes = Process.GetProcessesByName(current.ProcessName); //Loop through the running processes in with the same name foreach (Process process in processes) { //忽略当前进程<strong> </strong> if (process.Id != current.Id) { //Make sure that the process is running from the exe file. if (Assembly.GetExecutingAssembly().Location.Replace("/ ", "\\ ") == current.MainModule.FileName) { //Return the other process instance. return process; } } } //No other instance was found, return null. return null; } }方法1：不能避免多用户时的情况，多用户登陆系统时，还是可以开启多个实例的。

方法2：检查系统进程，可以解决多用户的问题，推荐方法2.