可以使用互斥体Mutex类型完成此功能。见如下代码：
[STAThread]
public static void Main(string[] args)
{
//声明互斥体。
Mutex mutex = new Mutex(false, "ThisShouldOnlyRunOnce");
//判断互斥体是否使用中。
bool Running = !mutex.WaitOne(0, false);
if (! Running)
Application.Run(new FormLogin());
else
MessageBox.Show("应用程序已经启动！");
}
[STAThread]
public static void Main(string[] args)
{
//声明互斥体。
Mutex mutex = new Mutex(false, "ThisShouldOnlyRunOnce");
//判断互斥体是否使用中。
bool Running = !mutex.WaitOne(0, false);
if (! Running)
Application.Run(new FormLogin());
else
MessageBox.Show("应用程序已经启动！");
}
using System;
using System.Runtime.InteropServices;
using System.Windows.Forms;
using System.Diagnostics;
using System.Reflection; public class OneInstnace
{
[STAThread]
public static void Main()
{
//Get the running instance.
Process instance = RunningInstance();
if (instance == null)
{
//There isn't another instance, show our form.
Application.Run (new Form());
}
else
{
//There is another instance of this process.
HandleRunningInstance(instance);
}
}
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)
{
//Ignore the current process
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;
}
public static void HandleRunningInstance(Process instance)
{
//Make sure the window is not minimized or maximized
ShowWindowAsync (instance.MainWindowHandle , WS_SHOWNORMAL);
//Set the real intance to foreground window
SetForegroundWindow (instance.MainWindowHandle);
}
[DllImport("User32.dll")]
private static extern bool ShowWindowAsync( IntPtr hWnd, int cmdShow);
[DllImport("User32.dll")] private static extern bool
SetForegroundWindow(IntPtr hWnd);
private const int WS_SHOWNORMAL = 1;
}
思路,我们在运行程序前,查找进程中是否有同名的进程,同时运行位置也相同,如是没有运行该程序,如果有,就将同名的同位置的程序窗口置前.主要代码:
public static Process RunningInstance()
{
Process current = Process.GetCurrentProcess();
Process[] processes = Process.GetProcessesByName (current.ProcessName);
//查找相同名称的进程
foreach (Process process in processes)
{
//忽略当前进程
if (process.Id != current.Id)
{
//确认相同进程的程序运行位置是否一样.
if (Assembly.GetExecutingAssembly().Location.Replace("/", "\\") == current.MainModule.FileName)
{
//Return the other process instance.
return process;
}
}
}
//No other instance was found, return null.
return null;
}
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