delphi Windows 编程[8] - WM

delphi Windows 编程[8] - WM_PAINT 消息

Windows 编程[8] - WM_PAINT 消息

program Project1;

uses

Windows, Messages;

{供 WM_PAINT 消息调用的自定义过程}

procedure OnPaint(h: HWND);

const

str = 'CodeGear Delphi 2007';

var

DC: HDC;

ps: PAINTSTRUCT;

Rect: TRect;

begin

MessageBeep(0);

DC := BeginPaint(h, ps);

GetClientRect(h, Rect);

DrawText(DC, PChar(str), -1, Rect, DT_SINGLELINE or DT_CENTER or DT_VCENTER);

EndPaint(h, ps);

end;

function WndProc(wnd: HWND; msg: UINT; wParam: Integer; lParam: Integer): Integer; stdcall;

begin

Result := 0;

case msg of

WM_PAINT : OnPaint(wnd); {在收到 WM_PAINT 消息时调用自定义的 OnPaint 过程}

WM_DESTROY: PostQuitMessage(0);

else

Result := DefWindowProc(wnd, msg, wParam, lParam);

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.

推荐分享