C++ GetWindowDC函数代码示例

// Windows-specific code to set the horizontal extent of the listbox, if
// necessary. If s is non-NULL, it's used to calculate the horizontal extent.
// Otherwise, all strings are used.
void wxListBox::SetHorizontalExtent(const wxString& s)
{
    // Only necessary if we want a horizontal scrollbar
    if (!(m_windowStyle & wxHSCROLL))
        return;
    TEXTMETRIC lpTextMetric;

    if ( !s.empty() )
    {
        int existingExtent = (int)SendMessage(GetHwnd(), LB_GETHORIZONTALEXTENT, 0, 0L);
        HDC dc = GetWindowDC(GetHwnd());
        HFONT oldFont = 0;
        if (GetFont().Ok() && GetFont().GetResourceHandle() != 0)
            oldFont = (HFONT) ::SelectObject(dc, (HFONT) GetFont().GetResourceHandle());

        GetTextMetrics(dc, &lpTextMetric);
        SIZE extentXY;
        ::GetTextExtentPoint32(dc, (LPTSTR) (const wxChar *)s, s.Length(), &extentXY);
        int extentX = (int)(extentXY.cx + lpTextMetric.tmAveCharWidth);

        if (oldFont)
            ::SelectObject(dc, oldFont);

        ReleaseDC(GetHwnd(), dc);
        if (extentX > existingExtent)
            SendMessage(GetHwnd(), LB_SETHORIZONTALEXTENT, LOWORD(extentX), 0L);
    }
    else
    {
        int largestExtent = 0;
        HDC dc = GetWindowDC(GetHwnd());
        HFONT oldFont = 0;
        if (GetFont().Ok() && GetFont().GetResourceHandle() != 0)
            oldFont = (HFONT) ::SelectObject(dc, (HFONT) GetFont().GetResourceHandle());

        GetTextMetrics(dc, &lpTextMetric);

        for (int i = 0; i < m_noItems; i++)
        {
            wxString str = GetString(i);
            SIZE extentXY;
            ::GetTextExtentPoint32(dc, str.c_str(), str.length(), &extentXY);
            int extentX = (int)(extentXY.cx + lpTextMetric.tmAveCharWidth);
            if (extentX > largestExtent)
                largestExtent = extentX;
        }
        if (oldFont)
            ::SelectObject(dc, oldFont);

        ReleaseDC(GetHwnd(), dc);
        SendMessage(GetHwnd(), LB_SETHORIZONTALEXTENT, LOWORD(largestExtent), 0L);
    }
}

// Draws a recessed border around the gauge
static void
DrawGaugeBorder(HWND hWnd)
{
	HDC		hDC = GetWindowDC(hWnd);
	RECT	rect;
	int		cx, cy;
	HPEN	hShadowPen = CreatePen(PS_SOLID, 1, GetSysColor(COLOR_BTNSHADOW));
	HGDIOBJ	hOldPen;

	GetWindowRect(hWnd, &rect);
	cx = rect.right - rect.left;
	cy = rect.bottom - rect.top;

	// Draw a dark gray line segment
	hOldPen = SelectObject(hDC, (HGDIOBJ)hShadowPen);
	MoveToEx(hDC, 0, cy - 1, NULL);
	LineTo(hDC, 0, 0);
	LineTo(hDC, cx - 1, 0);

	// Draw a white line segment
	SelectObject(hDC, GetStockObject(WHITE_PEN));
	MoveToEx(hDC, 0, cy - 1, NULL);
	LineTo(hDC, cx - 1, cy - 1);
	LineTo(hDC, cx - 1, 0);

	SelectObject(hDC, hOldPen);
	DeleteObject(hShadowPen);
	ReleaseDC(hWnd, hDC);
}

void DrawMap(HWND hWnd)
{
	HDC hDc = GetWindowDC(hWnd);

	HDC memDc = CreateCompatibleDC(NULL);  //缓存DC
	HBITMAP hBitMap = CreateCompatibleBitmap(hDc, 850, 650);
	SelectObject(memDc, hBitMap);
	//背景刷成绿色
	HBRUSH hBrushBack = CreateSolidBrush(RGB(0, 255, 0));
	RECT rectBack;
	rectBack.top = 0;
	rectBack.bottom = 650;
	rectBack.left = 0;
	rectBack.right = 850;
	FillRect(memDc, &rectBack, hBrushBack);

	DrawStoneAndBrike(memDc);
	
	DrawMan(memDc);

	BitBlt(hDc, 3, 25, 850, 650, memDc, 0, 0, SRCCOPY);//拷贝

	DeleteObject(memDc);
	DeleteObject(hBitMap);
	DeleteObject(hBrushBack);
	
	ReleaseDC(hWnd, hDc);
}

void CConfigMsgLogDlg::OnTimer(UINT nIDEvent)
{
    if (nIDEvent == m_unDispUpdateTimerId)
    {
        static bool bSwitchDisplay = true;
        CDC* pdc= GetWindowDC();
        pdc->SetTextColor(RGB(253,153,4));
        pdc->SetBkMode(TRANSPARENT);

        if(bSwitchDisplay)
        {
            SetWindowText("");
            pdc->DrawText(m_strCurrWndText,CRect(4,4,400,50),DT_END_ELLIPSIS);
            bSwitchDisplay = false;
        }
        else
        {
            pdc->DrawText(m_strCurrWndText,CRect(4,4,400,50),DT_END_ELLIPSIS);
            SetWindowText(m_strCurrWndText);
            bSwitchDisplay = true;
        }
        ReleaseDC(pdc);
    }
    CDialog::OnTimer(nIDEvent);
}

HBITMAP CaptureWindow(HWND hWnd)
{
	RECT wnd;

	if ( ! GetWindowRect(hWnd, & wnd) )
		return NULL;

	HDC hDC = GetWindowDC(hWnd);

	HBITMAP hBmp = CreateCompatibleBitmap(hDC, wnd.right - wnd.left, wnd.bottom - wnd.top);

	if ( hBmp )
	{
		HDC hMemDC   = CreateCompatibleDC(hDC);
		HGDIOBJ hOld = SelectObject(hMemDC, hBmp);

		BitBlt(hMemDC, 0, 0, wnd.right - wnd.left, wnd.bottom - wnd.top, 
			hDC, 0, 0, SRCCOPY);

		SelectObject(hMemDC, hOld);
		DeleteObject(hMemDC);
	}
	
	ReleaseDC(hWnd, hDC);

	return hBmp;
}

bool CFrame::findColor(CPnt5* pnt5)
{
	HWND hwnd = aigisHwnd();
	if (!hwnd)
	{
		return false;
	}
	HDC hdc = GetWindowDC(hwnd);
	if (!hdc)
	{
		return false;
	}

	bool bSame = true;
	for (size_t i = 0; i < EPD_MAX; i++)
	{
		POINT pntTmp = pnt5->getPoint((E_POINT_DIRECTION)i);
		COLORREF colorDefi = pnt5->getColor((E_POINT_DIRECTION)i);
		COLORREF colorFind = GetPixel(hdc, pntTmp.x, pntTmp.y);
		if (!CPnt5::isSameColor(colorDefi, colorFind ))
		{
			bSame = false;
			break;
		}
	}

	ReleaseDC(hwnd, hdc);
	return bSame;
}

void IWindow::selectWindow()
{
    hWndDC = GetWindowDC(hWnd);
	hBufferDC = CreateCompatibleDC(hWndDC);
	hWndBitmap = CreateCompatibleBitmap(hWndDC, wndWidth, wndHeight);
	hWndBitmap = (HBITMAP)SelectObject(hBufferDC, hWndBitmap);

	if(!BitBlt(hBufferDC, 0, 0, wndWidth, wndHeight, hWndDC, 0, 0, SRCCOPY)){
		DWORD dwError = GetLastError();
		_tprintf(_T("BitBlt: dwError = %i \n"), dwError);
	}

	if(hWndDC != NULL)
	{
		HPEN hPen = CreatePen(PS_SOLID, 3, RGB(0, 0, 0));
		hPen = (HPEN)SelectObject(hWndDC, hPen);

		MoveToEx(hWndDC, 1, 1, NULL);
		LineTo(hWndDC, wndWidth - 1, 1);
		LineTo(hWndDC, wndWidth - 1, wndHeight - 1);
		LineTo(hWndDC, 1, wndHeight - 1);
		LineTo(hWndDC, 1, 1);

		DeleteObject(SelectObject(hWndDC, hPen));
	}
}

LRESULT CALLBACK ToolbarWndProc(HWND hWnd, UINT Msg, WPARAM wParam, LPARAM lParam)
{
  switch (Msg)
  {
    case WM_NOTIFY:
    {
      switch (((LPNMHDR) lParam)->code)
      {
        case TTN_GETDISPINFOA:
        case TTN_GETDISPINFOW:
        {
          LPNMTTDISPINFO Info = (LPNMTTDISPINFO) lParam;
          Info->hinst = GetModuleHandle(NULL);
          Info->lpszText = MAKEINTRESOURCE(Info->hdr.idFrom);
          break;
        }
      }
      return 0;
    }
    case WM_NCPAINT:
    {
      RECT R;
      GetWindowRect(hWnd, &R);
      R.right -= R.left;
      R.bottom -= R.top;
      R.left = 0;
      R.top = 0;
      HDC DC = GetWindowDC(hWnd);
      DrawEdge(DC, &R, EDGE_ETCHED, BF_RECT);
      ReleaseDC(hWnd, DC);
      return 0;
    }
  }
  return CallWindowProc((WNDPROC)DefaultToolbarWndProc, hWnd, Msg, wParam, lParam);
}

void CttView::BsmLine(CPoint st, CPoint ed)
{
	CDC* pDC = GetWindowDC();
	COLORREF color = RGB(0,0,0);
	int x,y;
	int dx=(((ed.x-st.x)>0)<<1)-1;
	int dy=(((ed.y-st.y)>0)<<1)-1;	//算y的增量是1还是-1
	//x若相等，则为横着的直线
	if(ed.x==st.x){
		int x=st.x, y=st.y;
		while(y!=ed.y){
			pDC->SetPixel(x,y,color);
			y+=dy;
		}
		pDC->SetPixel(x,y,color);
		return;
	}

	//斜率小于等于1 / 大于1
	if(fabs((1.0*ed.y-st.y)/(1.0*ed.x-st.x)) <= 1.0){
		if(st.x > ed.x)swap(st,ed);		//将小的x放st、大的放ed
		dy=(((ed.y-st.y)>0)<<1)-1;
		x=st.x;
		y=st.y;
		int dtx=ed.x-st.x;
		int dty=(ed.y-st.y)*dy;
		int e=2*dty-dtx;
		while(x!=ed.x || y!=ed.y){
			pDC->SetPixel(x,y,color);
			if(e>=0){
				x++;
				y+=dy;
				e+=dty+dty-dtx-dtx;
			}else{
				x++;
				e+=dty+dty;
			}
		}
	}else{	//斜率大于1，则xy交换
		if(st.y > ed.y)swap(st,ed);		//将小的y放st、大的放ed
		dx=(((ed.x-st.x)>0)<<1)-1;
		x=st.x;
		y=st.y;
		int dtx=(ed.x-st.x)*dx;
		int dty=ed.y-st.y;
		int e=2*dtx-dty;
		while(x!=ed.x || y!=ed.y){
			pDC->SetPixel(x,y,color);
			if(e>=0){
				y++;
				x+=dx;
				e+=dtx+dtx-dty-dty;
			}else{
				y++;
				e+=dtx+dtx;
			}
		}
	}
	pDC->SetPixel(x,y,color);
}

//-----------------------------------------------------------------------------
// Name: HighlightWindow (from MSDN Spy Sample)
// Object: highlight or unhightlight a window
// Parameters : 
//     in : HWND hwnd : target window handle
//          BOOL fDraw : TRUE to draw, FALSE to clear
// Return : TRUE on success
//-----------------------------------------------------------------------------
void CSelectWindow::HighlightWindow( HWND hwnd, BOOL fDraw )
{
    #define DINV                3
    HDC hdc;
    RECT rc;
    BOOL bBorderOn;
    bBorderOn = fDraw;

    if (hwnd == NULL || !IsWindow(hwnd))
        return;

    hdc = GetWindowDC(hwnd);
    GetWindowRect(hwnd, &rc);
    OffsetRect(&rc, -rc.left, -rc.top);

    if (!IsRectEmpty(&rc))
    {
        PatBlt(hdc, rc.left, rc.top, rc.right - rc.left, DINV,  DSTINVERT);
        PatBlt(hdc, rc.left, rc.bottom - DINV, DINV,
            -(rc.bottom - rc.top - 2 * DINV), DSTINVERT);
        PatBlt(hdc, rc.right - DINV, rc.top + DINV, DINV,
            rc.bottom - rc.top - 2 * DINV, DSTINVERT);
        PatBlt(hdc, rc.right, rc.bottom - DINV, -(rc.right - rc.left),
            DINV, DSTINVERT);
    }

    ReleaseDC(hwnd, hdc);
}

void CAboutDlg::OnNcPaint() 
{
	CDC*	pDC = GetWindowDC();
	CRect	rc, rcCut,rcDraw;
	GetWindowRect(&rc);
	rcDraw.top		=  0;
	rcDraw.left		=  0;
	rcDraw.right	= rc.Width() ;
	rcDraw.bottom	= rc.Height();

	CRect rcClient;
	GetClientRect(&rcClient);
	ClientToScreen(&rcClient);
	rcCut.left = rcClient.left - rc.left;
	rcCut.right = rcClient.right - rc.left;
	rcCut.top = rcClient.top - rc.top;
	rcCut.bottom = rcClient.bottom - rc.top;

	CRgn rgnCut,rgnResult;	  
	rgnCut.CreateRectRgnIndirect(&rcCut);
	rgnResult.CreateRectRgnIndirect(&rcDraw);
	rgnResult.CombineRgn(&rgnResult,&rgnCut, RGN_XOR);	
	pDC->SelectClipRgn(&rgnResult);

	pDC->FillSolidRect(rcDraw, RGB(0, 119, 158));
	ReleaseDC(pDC);
}

/*
 * frame_draw_end - フレームの描画終了、フレームの最終位置を返す
 */
int frame_draw_end(const HWND hWnd)
{
	HDC hdc;
	int draw_cnt;
	int ret;

	if (frame_rect[0].left == 0 && frame_rect[0].right == 0 &&
		frame_rect[0].top == 0 && frame_rect[0].bottom == 0) {
		frame_free();
		return -1;
	}

	// 前回描画分を消去
	hdc = GetWindowDC(hWnd);
	for (draw_cnt = 0;draw_cnt < FRAME_CNT;draw_cnt++) {
		DrawFocusRect(hdc, (LPRECT)&frame_rect[draw_cnt]);
	}
	ReleaseDC(hWnd, hdc);

	// 境界位置の取得
	ret = frame_rect[0].left - GetSystemMetrics(SM_CXFRAME);

	frame_free();
	return ret;
}

FilteredListBox::FilteredListBox( DWORD dwStyle,int x,int y,int nWidth,int nHeigth,HWND hWndParent,HMENU hMenu,HINSTANCE hInstance )
	:ListBox(dwStyle | LBS_OWNERDRAWVARIABLE | LBS_HASSTRINGS,WS_EX_CLIENTEDGE,x,y,nWidth,nHeigth,hWndParent,hMenu,hInstance)
{
	HDC dc = GetWindowDC();
	GetTextMetrics(dc,&m_TextMetrics);
	ReleaseDC(dc);
}

// WM_MEASUREITEM handler
// Since we have owner drawn menus, we need to provide information about 
//  the menus back to Windows so it can layout the menubar appropriately.
BOOL cef_dark_window::HandleMeasureItem(LPMEASUREITEMSTRUCT lpMIS)
{
    static wchar_t szMenuString[256] = L"";

    if (lpMIS->CtlType == ODT_MENU) {
        HDC dc      = GetWindowDC();
        HMENU menu  = GetMenu();
        int items   = ::GetMenuItemCount(menu);
        
        InitMenuFont();
        
        HGDIOBJ fontOld = ::SelectObject(dc, mMenuFont);            

        ::GetMenuString(menu, lpMIS->itemID, szMenuString, _countof(szMenuString), MF_BYCOMMAND);

        RECT rectTemp;
        SetRectEmpty(&rectTemp);

        // Calc the size of this menu item 
        ::DrawText(dc, szMenuString, ::wcslen(szMenuString), &rectTemp, DT_SINGLELINE|DT_CALCRECT);

        lpMIS->itemHeight = ::RectHeight(rectTemp);
        lpMIS->itemWidth = ::RectWidth(rectTemp);
 
        ::SelectObject(dc, fontOld);            
        ReleaseDC(dc);
        return TRUE;
    }

    return FALSE;
}

int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
                    PSTR szCmdLine, int nCmdShow)			
{									
    MSG       msg;	
	HDC	hdcWindow;

	RegisterMyWindow(hInstance);

   	if (!InitialiseMyWindow(hInstance, nCmdShow))
		return FALSE;

	hdcWindow = GetWindowDC (Application.ghwnd);
	Application.setBuffers();

	while (Application.Running())					
    {							
		if (PeekMessage(&msg,NULL,0,0,PM_REMOVE))
		{
		    if (msg.message==WM_QUIT)
				break;
			TranslateMessage (&msg);							
			DispatchMessage (&msg);
		}

		else
		{	
			Application.MainLoop();
		}
    }

    Application.releaseResources();
	return msg.wParam ;										
}