[转载]C#获取进程的主窗口句柄

public class User32API
 
{
 
    private static Hashtable processWnd = null;
 
    public delegate bool WNDENUMPROC(IntPtr hwnd, uint lParam);
 
    static User32API()
 
    {
 
        if (processWnd == null)
 
        {
 
            processWnd = new Hashtable();
 
        }
 
    }
 
    [DllImport("user32.dll", EntryPoint = "EnumWindows", SetLastError = true)]
 
    public static extern bool EnumWindows(WNDENUMPROC lpEnumFunc, uint lParam);
 
    [DllImport("user32.dll", EntryPoint = "GetParent", SetLastError = true)]
 
    public static extern IntPtr GetParent(IntPtr hWnd);
 
    [DllImport("user32.dll", EntryPoint = "GetWindowThreadProcessId")]
 
    public static extern uint GetWindowThreadProcessId(IntPtr hWnd, ref uint lpdwProcessId);
 
    [DllImport("user32.dll", EntryPoint = "IsWindow")]
 
    public static extern bool IsWindow(IntPtr hWnd);
 
    [DllImport("kernel32.dll", EntryPoint = "SetLastError")]
 
    public static extern void SetLastError(uint dwErrCode);
 
    public static IntPtr GetCurrentWindowHandle()
 
    {
 
        IntPtr ptrWnd = IntPtr.Zero;
 
        uint uiPid = (uint)Process.GetCurrentProcess().Id;  // 当前进程 ID
 
        object objWnd = processWnd[uiPid];
 
        if (objWnd != null)
 
        {
 
            ptrWnd = (IntPtr)objWnd;
 
            if (ptrWnd != IntPtr.Zero && IsWindow(ptrWnd))  // 从缓存中获取句柄
 
            {
 
                return ptrWnd;
 
            }
 
            else
 
            {
 
                ptrWnd = IntPtr.Zero;
 
            }
 
        }
 
        bool bResult = EnumWindows(new WNDENUMPROC(EnumWindowsProc), uiPid);
 
        // 枚举窗口返回 false 并且没有错误号时表明获取成功
 
        if (!bResult && Marshal.GetLastWin32Error() == )
 
        {
 
            objWnd = processWnd[uiPid];
 
            if (objWnd != null)
 
            {
 
                ptrWnd = (IntPtr)objWnd;
 
            }
 
        }
 
        return ptrWnd;
 
    }
 
    private static bool EnumWindowsProc(IntPtr hwnd, uint lParam)
 
    {
 
        uint uiPid = ;
 
        if (GetParent(hwnd) == IntPtr.Zero)
 
        {
 
            GetWindowThreadProcessId(hwnd, ref uiPid);
 
            if (uiPid == lParam)    // 找到进程对应的主窗口句柄
 
            {
 
                processWnd[uiPid] = hwnd;   // 把句柄缓存起来
 
                SetLastError();    // 设置无错误
 
                return false;   // 返回 false 以终止枚举窗口
 
            }
 
        }
 
        return true;
 
    }
 
}

调用User32API.GetCurrentWindowHandle()即可返回当前进程的主窗口句柄，如果获取失败则返回IntPtr.Zero。

http://www.cnblogs.com/qiuyi21/articles/1302732.html