PreTranslateMessage函数顾名思义,就是在消息被翻译之前,做的一些事.我们可以屏蔽一个键或一个命令.
下面是一些常用消息的相关信息.这些信息放pMsg中.
WM_KEYDOWN nVirtKey = (int) wParam; /*虚键值,和ascll码有许多相同的地方 */ lKeyData = lParam; /*和硬件有关 */ WM_CHAR chCharCode = (TCHAR) wParam; lKeyData = lParam; WM_COMMAND wNotifyCode = HIWORD(wParam); wID = LOWORD(wParam); hwndCtl = (HWND) lParam; WM_LBUTTONDOWN fwKeys = wParam; // xPos = LOWORD(lParam); // 鼠标横坐标 yPos = HIWORD(lParam); // 鼠标纵坐标 fwKeys MK_CONTROL MK_LBUTTON MK_MBUTTON MK_RBUTTON MK_SHIFT WM_MOUSEMOVE fwKeys = wParam; xPos = LOWORD(lParam); yPos = HIWORD(lParam); 下面这个例子演示了,PreTranslateMessage的常用用法. BOOL CPreTranslateDlg::PreTranslateMessage(MSG* pMsg) { if(WM_KEYDOWN == pMsg->message ) if(0x30 == (int) pMsg->wParam) { return true; /*禁止在编辑框中输入0(ascll 0x30)*/ } if(WM_CHAR == pMsg->message ) if('A' == (TCHAR) pMsg->wParam) { return true; /*禁止在编辑框中输入'A'*/ } if(WM_MOUSEMOVE == pMsg->message) if(MK_CONTROL & pMsg->wParam) /*当ctrl被按下鼠标移动时,显示相关信息*/ { int xPos = LOWORD(pMsg->lParam); int yPos = HIWORD(pMsg->lParam); CString str ; str.Format("鼠标的坐标%d %d",xPos,yPos); AfxMessageBox(str); } if(WM_COMMAND == pMsg->message) if(ID_1 == LOWORD(pMsg->wParam))//禁止菜单项ID_1,注意按钮发送的是BN_CLICKED { return true; } return CDialog::PreTranslateMessage(pMsg); }
