关于这个内容，我参考了一篇文章：https://blog.csdn.net/bimabushihaodongxi/article/details/70942975 

2022.07.29 更新

WM_MOUSEWHEEL 消息特殊处理：http://huidong.xyz/index.php?mode=2&id=448 

总结一下吧，在窗口过程函数中把鼠标消息整合成一个 EasyX 的 ExMessage，就像下面这样，很浓缩了。

    // 消息记录
        switch (msg)
        {
            // EM_MOUSE
        case WM_MOUSEMOVE:
        case WM_MOUSEWHEEL:
        case WM_LBUTTONDOWN:
        case WM_LBUTTONUP:
        case WM_LBUTTONDBLCLK:
        case WM_MBUTTONDOWN:
        case WM_MBUTTONUP:
        case WM_MBUTTONDBLCLK:
        case WM_RBUTTONDOWN:
        case WM_RBUTTONUP:
        case WM_RBUTTONDBLCLK:
        {
            ExMessage msgMouse = {};
            msgMouse.message = msg;
            msgMouse.x = GET_X_LPARAM(lParam);
            msgMouse.y = GET_Y_LPARAM(lParam);
            msgMouse.wheel = GET_WHEEL_DELTA_WPARAM(wParam);
            msgMouse.shift = LOWORD(wParam) & 0x04 ? true : false;
            msgMouse.ctrl = LOWORD(wParam) & 0x08 ? true : false;
            msgMouse.lbutton = LOWORD(wParam) & 0x01 ? true : false;
            msgMouse.mbutton = LOWORD(wParam) & 0x10 ? true : false;
            msgMouse.rbutton = LOWORD(wParam) & 0x02 ? true : false;

            // 有滚轮消息时，得到的坐标是屏幕坐标，需要转换
            if (msgMouse.wheel)
            {
                POINT p = { msgMouse.x ,msgMouse.y };
                ScreenToClient(g_vecWindows[indexWnd].hWnd, &p);
                msgMouse.x = (short)p.x;
                msgMouse.y = (short)p.y;
            }

            g_vecWindows[indexWnd].vecMessage.push_back(msgMouse);
        }
        break;