首页 > 代码库 > Delphi7 API(5) 消息篇:WM_LBUTTONDOWN、LBUTTONUP、LBUTTONMOVE
Delphi7 API(5) 消息篇:WM_LBUTTONDOWN、LBUTTONUP、LBUTTONMOVE
示例如下
program Project1;uses Windows, Messages;{供 WM_LBUTTONDOWN 消息调用的自定义过程}procedure OnLButtonDown(h: HWND);var BrushHandle: HBRUSH; Rect: TRect;begin GetClientRect(h, Rect); {获取客户区矩形} BrushHandle := CreateSolidBrush(RGB(0,0,0)); {建立黑色笔刷} FillRect(GetDC(h), Rect, BrushHandle); {填充客户区} DeleteObject(BrushHandle); {删除笔刷}end;{供 WM_LBUTTONUP 消息调用的自定义过程}procedure OnLButtonUp(h: HWND);var Rect: TRect;begin GetClientRect(h, Rect); {获取客户区矩形} InvalidateRect(h, @Rect, True); {使客户区无效, 从而强制重绘}end;{供 WM_MOUSEMOVE 消息调用的自定义过程}procedure onm ouseMove(h: HWND; lParam: Integer);var pt: TPoint; buf: array[0..255] of Char;begin pt.X := LoWord(lParam); {lParam 中的低两位是 x 坐标} pt.Y := HiWord(lParam); {lParam 中的高两位是 y 坐标} wvsprintf(buf, ‘%d, %d‘, @pt); {格式化到缓冲区} SetWindowText(h, buf); {显示在标题}end;function WndProc(wnd: HWND; msg: UINT; wParam: Integer; lParam: Integer): Integer; stdcall;begin Result := 0; case msg of WM_LBUTTONDOWN: OnLButtonDown(wnd); {鼠标左键按下的消息} WM_LBUTTONUP : OnLButtonUp(wnd); {鼠标左键抬起的消息} WM_MOUSEMOVE : onm ouseMove(wnd, lParam); {鼠标移动的消息, 坐标位置在 lParam 中} WM_DESTROY : PostQuitMessage(0); else Result := DefWindowProc(wnd, msg, wParam, lParam); end;end;function RegMyWndClass: Boolean;var cls: TWndClass;begin cls.style := CS_HREDRAW or CS_VREDRAW; cls.lpfnWndProc := @WndProc; cls.cbClsExtra := 0; cls.cbWndExtra := 0; cls.hInstance := HInstance; cls.hIcon := 0; cls.hCursor := LoadCursor(0, IDC_ARROW); cls.hbrBackground := HBRUSH(COLOR_WINDOW + 1 ); cls.lpszMenuName := nil; cls.lpszClassName := ‘MyWnd‘; Result := RegisterClass(cls) <> 0;end;{程序入口}const tit = ‘New Form‘; ws = WS_OVERLAPPEDWINDOW; x = 100; y = 100; w = 300; h = 180;var hWnd: THandle; Msg : TMsg;begin RegMyWndClass; hWnd := CreateWindow(‘MyWnd‘, tit, ws, x, y, w, h, 0, 0, HInstance, nil); ShowWindow(hWnd, SW_SHOWNORMAL); UpdateWindow(hWnd); while(GetMessage(Msg, 0, 0, 0)) do begin TranslateMessage(Msg); DispatchMessage(Msg); end;end.
Delphi7 API(5) 消息篇:WM_LBUTTONDOWN、LBUTTONUP、LBUTTONMOVE
声明:以上内容来自用户投稿及互联网公开渠道收集整理发布,本网站不拥有所有权,未作人工编辑处理,也不承担相关法律责任,若内容有误或涉及侵权可进行投诉: 投诉/举报 工作人员会在5个工作日内联系你,一经查实,本站将立刻删除涉嫌侵权内容。