c++ - 鼠标锁定水平/垂直移动

Question

我希望鼠标光标分别锁定在 X 或 Y 轴上的指定点上。我设法用低级鼠标 proc 和键盘 proc 实现了这一点(需要键盘 proc 作为用户希望鼠标跟随的移动的输入 - 垂直或水平)。但是，我的问题是 - 在锁定移动时，比如用 F7 水平 - 当我按下鼠标按钮或使用鼠标滚轮时，锁定移动会因为一些我无法理解的奇怪原因而被释放，我显然不想除非用户这么说(即按 F6)，否则它将被释放。这是代码，您可以检查它并查看我正在谈论的问题:

#define _WIN32_WINNT 0x0501

#include <iostream>
#include <windows.h>
using namespace std;

bool block = false;
POINT p;
HHOOK hHook,hHook2;
unsigned int status = 0;
LRESULT CALLBACK LowLevelKeyboardProc(int nCode, WPARAM wParam, LPARAM lParam)
{
    KBDLLHOOKSTRUCT key;
    memcpy(&key,(void*)lParam,sizeof(KBDLLHOOKSTRUCT));

    if( wParam == WM_KEYDOWN)
    {
        if(key.vkCode == VK_F7)
        {
             //Horizontal only
             if (GetCursorPos(&p)) status = 1;
        }
        else if(key.vkCode == VK_F8)
        {
             //Vertical only
             if (GetCursorPos(&p)) status = 2;
        }
        else if(key.vkCode == VK_F6)
        {
             //Normal
             status = 0;
        }
    }
    return CallNextHookEx(hHook, nCode, wParam, lParam);
}

LRESULT CALLBACK LowLevelMouseProc(int nCode, WPARAM wParam, LPARAM lParam)
{
    MSLLHOOKSTRUCT key;
    memcpy(&key,(void*)lParam,sizeof(MSLLHOOKSTRUCT));

    if(wParam == WM_MOUSEMOVE)
    {
        if(status == 1)
        {
            SetCursorPos(key.pt.x,p.y);
        }
        else if(status == 2)
        {
            SetCursorPos(p.x,key.pt.y);
        }
        else
        {
            return CallNextHookEx(hHook2, nCode, wParam, lParam);
        }
    }
    else
    {
        return CallNextHookEx(hHook2, nCode, wParam, lParam);
    }
}

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
{
  cout<<"F7 to allow Horizontal moving ONLY"<<endl;
  cout<<"F8 to allow Vertical moving ONLY"<<endl;
  cout<<"F6 to move freely"<<endl;
  hHook = SetWindowsHookEx(WH_KEYBOARD_LL, LowLevelKeyboardProc, hInstance, 0);
  hHook2 = SetWindowsHookEx(WH_MOUSE_LL, LowLevelMouseProc, hInstance, 0);
  MSG msg;
  while(GetMessage(&msg, NULL, 0, 0))
  {
    TranslateMessage(&msg);
    DispatchMessage(&msg);
  }
  return msg.wParam;
}

Answer 1

您的应用程序中可能有一个低级 Hook ，我认为它花费的时间超过 200 毫秒，或者您在调试器中设置了断点；这将导致 Windows 注销您的窗口 Hook 。