csharp 用于检查其他进程的Singleton类

Posted 2021-05-12

static class clsProcessChecker
{
    static string _requiredString;

    internal static class NativeMethods
    {
        [DllImport("user32.dll")]
        public static extern bool ShowWindowAsync(IntPtr hWnd, int nCmdShow);

        [DllImport("user32.dll")]
        public static extern bool SetForegroundWindow(IntPtr hWnd);

        [DllImport("user32.dll")]
        public static extern bool EnumWindows(EnumWindowsProcDel lpEnumFunc,
            Int32 lParam);

        [DllImport("user32.dll")]
        public static extern int GetWindowThreadProcessId(IntPtr hWnd,
            ref Int32 lpdwProcessId);

        [DllImport("user32.dll")]
        public static extern int GetWindowText(IntPtr hWnd, StringBuilder lpString,
            Int32 nMaxCount);

        public const int SW_SHOWNORMAL = 1;
    }

    public delegate bool EnumWindowsProcDel(IntPtr hWnd, Int32 lParam);

    static private bool EnumWindowsProc(IntPtr hWnd, Int32 lParam)
    {
        int processId = 0;
        NativeMethods.GetWindowThreadProcessId(hWnd, ref processId);

        StringBuilder caption = new StringBuilder(1024);
        NativeMethods.GetWindowText(hWnd, caption, 1024);

        if (processId == lParam && (caption.ToString().IndexOf(_requiredString,
            StringComparison.OrdinalIgnoreCase) != -1))
        {
            NativeMethods.ShowWindowAsync(hWnd, NativeMethods.SW_SHOWNORMAL);
            NativeMethods.SetForegroundWindow(hWnd);
        }
        return true;
    }

    static public bool IsOnlyProcess(string forceTitle)
    {
        _requiredString = forceTitle;
        foreach (Process proc in Process.GetProcessesByName(Application.ProductName))
        {
            if (proc.Id != Process.GetCurrentProcess().Id)
            {
                NativeMethods.EnumWindows(new EnumWindowsProcDel(EnumWindowsProc),
                    proc.Id);
                return false;
            }
        }
        return true;
    }
}