[c#] Close a MessageBox after several seconds

If anyone wants AutoClosingMessageBox in c++ I have implemented the equivalent code here is the link to gists

static intptr_t MessageBoxHookProc(int nCode, intptr_t wParam, intptr_t lParam)
{
    if (nCode < 0)
        return CallNextHookEx(hHook, nCode, wParam, lParam);

    auto msg = reinterpret_cast<CWPRETSTRUCT*>(lParam);
    auto hook = hHook;

    //Hook Messagebox on Initialization.
    if (!hookCaption.empty() && msg->message == WM_INITDIALOG)
    {
        int nLength = GetWindowTextLength(msg->hwnd);
        char* text = new char[captionLen + 1];

        GetWindowText(msg->hwnd, text, captionLen + 1);

        //If Caption window found Unhook it.
        if (hookCaption == text)
        {
            hookCaption = string("");
            SetTimer(msg->hwnd, (uintptr_t)timerID, hookTimeout, (TIMERPROC)hookTimer);
            UnhookWindowsHookEx(hHook);
            hHook = 0;
        }
    }

    return CallNextHookEx(hook, nCode, wParam, lParam);
}