操作方法

操作方法

private:

CBitmap m_bitmap;

BOOL CModify::OnInitDialog()

{

if(!CDialog::OnInitDialog())

{

return FALSE;

}

m_bitmap.LoadBitmap(IDB_BITMAP_MODIFY);

return TRUE;

}

void CModify::OnPaint()

{

CPaintDC dc(this);

CRect rect;

GetClientRect(&rect);

if(m_bitmap.GetSafeHandle())

{

DrawTransparentBitmap( dc.GetSafeHdc(), (HBITMAP)m_bitmap.GetSafeHandle(), 0, 0, 0, 0, 

rect.Width(), rect.Height(), RGB(0,255,0) );

}

}

绘图函数

void DrawTransparentBitmap(HDC hdc,HBITMAP hBitmap, int xStart, int yStart, 

int xBitmap, int yBitmap, int xWidth, int yHeight,

COLORREF cTransparentColor)

{              

   COLORREF   cColor;

   HBITMAP    bmAndBack, bmAndObject, bmAndMem, bmSave;

   HBITMAP    bmBackOld, bmObjectOld, bmMemOld, bmSaveOld, bmTempOld;

   HDC        hdcMem, hdcBack, hdcObject, hdcTemp, hdcSave;

   POINT      ptSize;

 

   if(NULL == hdc || NULL == hBitmap)

return;

   hdcTemp = CreateCompatibleDC(hdc);

   bmTempOld = (HBITMAP)SelectObject(hdcTemp, hBitmap);   // Select the bitmap

 

   ptSize.x = xWidth;            // Get width of bitmap

   ptSize.y = yHeight;           // Get height of bitmap

   DPtoLP(hdcTemp, &ptSize, 1);      // Convert from device

                                     // to logical points

   hdcBack   = CreateCompatibleDC(hdc);

   hdcObject = CreateCompatibleDC(hdc);

   hdcMem    = CreateCompatibleDC(hdc);

   hdcSave   = CreateCompatibleDC(hdc);

 

   // Create a bitmap for each DC. DCs are required for a number of

   // GDI functions.

 

   // Monochrome DC

 

   bmAndBack   = CreateBitmap(ptSize.x, ptSize.y, 1, 1, NULL);

 

   // Monochrome DC

   bmAndObject = CreateBitmap(ptSize.x, ptSize.y, 1, 1, NULL);

 

   bmAndMem    = CreateCompatibleBitmap(hdc, ptSize.x, ptSize.y);

   bmSave      = CreateCompatibleBitmap(hdc, ptSize.x, ptSize.y);

 

   // Each DC must select a bitmap object to store pixel data.

   bmBackOld   = (HBITMAP)SelectObject(hdcBack, bmAndBack);

   bmObjectOld = (HBITMAP)SelectObject(hdcObject, bmAndObject);

   bmMemOld    = (HBITMAP)SelectObject(hdcMem, bmAndMem);

   bmSaveOld   = (HBITMAP)SelectObject(hdcSave, bmSave);

 

   // Set proper mapping mode.

   SetMapMode(hdcTemp, GetMapMode(hdc));

 

 

   // Save the bitmap sent here, because it will be overwritten.

   BitBlt(hdcSave, 0, 0, ptSize.x, ptSize.y, hdcTemp, xBitmap, yBitmap, SRCCOPY);

 

   // Set the background color of the source DC to the color.

   // contained in the parts of the bitmap that should be transparent

   cColor = SetBkColor(hdcTemp, cTransparentColor);

 

   // Create the object mask for the bitmap by performing a BitBlt()

   // from the source bitmap to a monochrome bitmap.

   BitBlt(hdcObject, 0, 0, ptSize.x, ptSize.y, hdcTemp, xBitmap, yBitmap,

          SRCCOPY);

 

   // Set the background color of the source DC back to the original

   // color.

   SetBkColor(hdcTemp, cColor);

 

 

   // Create the inverse of the object mask.

   BitBlt(hdcBack, 0, 0, ptSize.x, ptSize.y, hdcObject, 0, 0,

          NOTSRCCOPY);

 

   // Copy the background of the main DC to the destination.

   BitBlt(hdcMem, 0, 0, ptSize.x, ptSize.y, hdc, xStart, yStart,

          SRCCOPY);

 

   // Mask out the places where the bitmap will be placed.

   BitBlt(hdcMem, 0, 0, ptSize.x, ptSize.y, hdcObject, 0, 0, SRCAND);

 

   // Mask out the transparent colored pixels on the bitmap.

   BitBlt(hdcTemp, xBitmap, yBitmap, ptSize.x, ptSize.y, hdcBack, 0, 0, SRCAND);

 

   // XOR the bitmap with the background on the destination DC.

   BitBlt(hdcMem, 0, 0, ptSize.x, ptSize.y, hdcTemp, xBitmap, yBitmap, SRCPAINT);

 

 

   // Copy the destination to the screen.

   BitBlt(hdc, xStart, yStart, ptSize.x, ptSize.y, hdcMem, 0, 0,

          SRCCOPY);

 

   // Place the original bitmap back into the bitmap sent here.

   BitBlt(hdcTemp, xBitmap, yBitmap, ptSize.x, ptSize.y, hdcSave, 0, 0, SRCCOPY);

 

   // Delete the memory bitmaps.

   SelectObject(hdcTemp, bmTempOld);

 

   DeleteObject(SelectObject(hdcBack, bmBackOld));

   DeleteObject(SelectObject(hdcObject, bmObjectOld));

   DeleteObject(SelectObject(hdcMem, bmMemOld));

   DeleteObject(SelectObject(hdcSave, bmSaveOld));

 

   // Delete the memory DCs.

   DeleteDC(hdcMem);

   DeleteDC(hdcBack);

 

   DeleteDC(hdcObject);

   DeleteDC(hdcSave);

   DeleteDC(hdcTemp);

}