我这样钩，没钩到，是哪里有问题呢？

private static int CurHookProc(int nCode, Int32 wParam, IntPtr lParam)
        {
            CwpStruct lp = (CwpStruct)Marshal.PtrToStructure(lParam, typeof(CwpStruct));
            Debugger.Log(0, null, String.Format("{0:D},{1:D},{2:D}", nCode, (int)lp.wparam,(int)lp.lparam));
            if (lp.wparam == (IntPtr)WM_MOUSE.WM_SETCURSOR)
            {
                Debugger.Log(0, null, "SETCURSOR");
                return 0;
            }
            return Win32API.CallNextHookEx(mCurHook, nCode, wParam, lParam);
        }

if (mCurHook == IntPtr.Zero)
            {
                mCurHookProcedure = CurHookProc;
                //注册线程钩子时第三个参数是空
                mCurHook = Win32API.SetWindowsHookEx(WH_CODE.WH_CALLWNDPROCRET, mCurHookProcedure, IntPtr.Zero, result);
                if (mCurHook == IntPtr.Zero)
                {
                    return false;
                }
            }