当我们启动一个程序，用 Process process = Process.Start(path);//path是程序的绝对路径

启动时，获取的process.Handle其实是进程的句柄，并不是窗口的句柄，而有时process.MainWindowHandle却等于0

此时就需要用枚举来获取启动进程的主窗口句柄了，代码如下

/// 
    /// 用于枚举子窗体是的委托    /// 
    /// 窗体句柄    /// 自定义    /// 
         public delegate bool EnumChildWindow(IntPtr WindowHandle, string num);    /// 
    /// 获取指定窗体的所有子窗体    /// 
    /// 窗体句柄    /// 回调委托    /// 自定义    /// 
         [DllImport("User32.dll")]    public static extern int EnumChildWindows(IntPtr WinHandle, EnumChildWindow ecw, string name);    /// 
    /// 获取指定窗体的标题    /// 
    /// 窗体句柄    /// 缓冲区取用于存储标题    /// 缓冲区大小    /// 
         [DllImport("User32.dll")]    public static extern int GetWindowText(IntPtr WinHandle, StringBuilder Title, int size);    /// 
    /// 获取窗体类型    /// 
    /// 窗体句柄    /// 类型    /// 缓冲区大小    /// 
         [DllImport("user32.dll")]    public static extern int GetClassName(IntPtr WinHandle, StringBuilder Type, int size);    /// 
    /// 根据句柄获得进程id值    /// 
    /// 句柄    ///     /// 
         [DllImport("user32")]    private static extern int GetWindowThreadProcessId(IntPtr handle, out int pid); IntPtr mainHwnd = IntPtr.Zero;//登录窗口句柄string typeName = string.Empty;//启动程序的窗口标题   /// 
    /// 枚举窗体    /// 
    ///     ///     /// 
         private bool EnumChild(IntPtr handle, string num)    {        StringBuilder title = new StringBuilder();        //StringBuilder type = new StringBuilder();        title.Length = 100;        //type.Length = 100;        GetWindowText(handle, title, 100);//取标题        //GetClassName(handle, type, 100);//取类型        if (title.ToString() == typeName)        {            mainHwnd = handle;            return false;        }        return true;    }//代码调用pubilc boolTest(){       FileVersionInfo myFileVersion = FileVersionInfo.GetVersionInfo(path);        typeName = myFileVersion.ProductName;//获取程序产品名称int waitTime = 0;     while (true)            {                               EnumChildWindow ecw = new EnumChildWindow(EnumChild);                EnumChildWindows(mainWindowHandle, ecw, "");                GetWindowRect(mainHwnd.ToInt32(), ref rectMain);                int pid = 0;                GetWindowThreadProcessId(mainHwnd, out pid);                //rectMain.Height - rectMain.Y < 300说明是登录窗口                if (mainHwnd != IntPtr.Zero && process.Id == pid && rectMain.Height - rectMain.Y < 300)//276                                    break;                waitTime++;                //30秒没打开程序，登录失败                if (waitTime >= 30)                    return false;                Thread.Sleep(1000);            }return true;}