DevExpress Winform使用单例运行程序方法和非DevExpress使用Mutex实现程序单实例运行且运行则激活窗体的方法

原文:DevExpress Winform使用单例运行程序方法和非DevExpress使用Mutex实现程序单实例运行且运行则激活窗体的方法

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本文链接：https://blog.csdn.net/u012097590/article/details/92806194

网上关于C#单例运行程序的方法都是比较简单，有些甚至是无法实现功能的，不知道他们试没试过就发帖，因为自己之前都是用第三方控件DevExpress，单例运行也是用它本身自带的一个方法，调用此方法需要引用DevExpress的DevExpress.DevAV.v17.1.Data.dll

static void Main()
        {
var appName= Process.GetCurrentProcess().ProcessName;
using (DevExpress.Internal.DevAVDataDirectoryHelper.SingleInstanceApplicationGuard(appName, out exit))
            {
                if (exit)
                    return;
                Application.EnableVisualStyles();
                Application.SetCompatibleTextRenderingDefault(false);
                Application.Run(new Form1());
            }
}
 

以前懒，看到有现成的就拿现成的，也没去想具体如何实现，刚好有人问起，才决定去看看源码，发现DevExpress的这个方法原来是用了Mutex来实现的，整合了一下资料，重新写一个供C#桌面应用程序通用的单例运行方法，代码如下：

其中需要引用以下命名空间:

using System;
using System.Diagnostics;
using System.Drawing;
using System.Runtime.InteropServices;
using System.Security;
using System.Threading;
 

/// <summary>
    /// 单实例应用程序--by涛神
    /// </summary>
    public class SingleInstanceApplication
    {
        /// <summary>
        /// 判断应用是否运行
        /// </summary>
        /// <param name="processName"></param>
        /// <param name="exit"></param>
        /// <returns></returns>
        public static IDisposable Guard(out bool exit)
        {
            Process currentProcess = Process.GetCurrentProcess();
            var processName = currentProcess.ProcessName;
            Mutex mutex = new Mutex(true, processName, out bool createNew);
            if (createNew)
            {
                exit = false;
            }
            else
            {
                Process[] processesByName = Process.GetProcessesByName(currentProcess.ProcessName);
                int num = 0;
                while (num < (int)processesByName.Length)
                {
                    Process process = processesByName[num];
                    if (process.Id == currentProcess.Id || !(process.MainWindowHandle != IntPtr.Zero))
                    {
                        num++;
                    }
                    else
                    {
                        WinApiHelper.SetForegroundWindow(process.MainWindowHandle);
                        WinApiHelper.RestoreWindowAsync(process.MainWindowHandle);
                        break;
                    }
                }
                exit = true;
            }
            return mutex;
        }
        private static class WinApiHelper
        {
            [SecuritySafeCritical]
            public static bool IsMaxmimized(IntPtr hwnd)
            {
                WinApiHelper.Import.WINDOWPLACEMENT wINDOWPLACEMENT = new WinApiHelper.Import.WINDOWPLACEMENT();
                if (!WinApiHelper.Import.GetWindowPlacement(hwnd, ref wINDOWPLACEMENT))
                {
                    return false;
                }
                return wINDOWPLACEMENT.showCmd == WinApiHelper.Import.ShowWindowCommands.ShowMaximized;
            }
 
            [SecuritySafeCritical]
            public static bool RestoreWindowAsync(IntPtr hwnd)
            {
                return WinApiHelper.Import.ShowWindowAsync(hwnd, (WinApiHelper.IsMaxmimized(hwnd) ? 3 : 9));
            }
 
            [SecuritySafeCritical]
            public static bool SetForegroundWindow(IntPtr hwnd)
            {
                return WinApiHelper.Import.SetForegroundWindow(hwnd);
            }
 
            private static class Import
            {
                [DllImport("user32.dll", CharSet = CharSet.None, ExactSpelling = false)]
                public static extern bool GetWindowPlacement(IntPtr hWnd, ref WinApiHelper.Import.WINDOWPLACEMENT lpwndpl);
 
                [DllImport("user32.dll", CharSet = CharSet.None, ExactSpelling = false)]
                public static extern bool SetForegroundWindow(IntPtr hWnd);
 
                [DllImport("user32.dll", CharSet = CharSet.None, ExactSpelling = false)]
                public static extern bool ShowWindowAsync(IntPtr hWnd, int nCmdShow);
 
                public enum ShowWindowCommands
                {
                    Hide,
                    Normal,
                    ShowMinimized,
                    ShowMaximized,
                    ShowNoActivate,
                    Show,
                    Minimize,
                    ShowMinNoActive,
                    ShowNA,
                    Restore,
                    ShowDefault,
                    ForceMinimize
                }
 
                public struct WINDOWPLACEMENT
                {
                    public int length;
 
                    public int flags;
 
                    public WinApiHelper.Import.ShowWindowCommands showCmd;
 
                    public Point ptMinPosition;
 
                    public Point ptMaxPosition;
 
                    public Rectangle rcNormalPosition;
                }
            }
        }
    }
 

调用的demo如下，亲测可以，若无法实现的请留言讨论（本文章是原创文章，转载请标明，盗版必究，觉得文章对你帮助的可以点个赞表示支持一下，谢谢）：

static void Main()
        {
            using(SingleInstanceApplication.Guard(out bool exit))
            {
                if (exit)
                    return;
                Application.EnableVisualStyles();
                Application.SetCompatibleTextRenderingDefault(false);
                Application.Run(new Form1());
            }
        }