Displaying a Bitmap

[maverick786us]

I have an MFCActiveX control, in which there is a ctrl class created by the wizard. Within that class there is a function named ondraw like this..

void CGregTestCtrl::OnDraw(
			CDC* pdc, const CRect& rcBounds, const CRect& rcInvalid)
{
	// TODO: Replace the following code with your own drawing code.
	 pdc->FillRect(rcBounds, CBrush::FromHandle((HBRUSH)GetStockObject(GRAY_BRUSH)));
	pdc->Ellipse(rcBounds);	

}

When I use this control anywhere in an application it displays an Ellipse. I want to display a Bitmap and some written text instead of that ellipse. So what all changes do I have to make in OnDraw() function??

[c0mgu1]

Hi,

If you don't want to see Ellipse comment the pregenarated code in OnDraw function.

If you want to display bitmap first load that in to memory and by using BitBlt() you can draw bitmap

http://www.desktoppack.com

[maverick786us]

Hi,

If you don't want to see Ellipse comment the pregenarated code in OnDraw function.

If you want to display bitmap first load that in to memory and by using BitBlt() you can draw bitmap

http://www.desktoppack.com

I have sluggish knowledge about that. Can you please write or show me the code of Bitmap??

[danandu]

I have sluggish knowledge about that. Can you please write or show me the code of Bitmap??

HI,

U CAN USE THIS CODE EXAMPLE FOR DISPLAYING BITMAPS ON SCREEN. BUT AS SAID BEFORE U SHOULD HAVE IT IN THE RESOURCES (i.e., IDB_BITMAP1)

/////////////// BITMAP /////////////
CBitmap bitmap;
CDC dcMemory;
bitmap.LoadBitmap(IDB_BITMAP1);
dcMemory.CreateCompatibleDC(&dcMemory);
dcMemory.SelectObject(&bitmap);
dc.BitBlt(120, 100, 161, 183, &dcMemory, 0, 0, SRCCOPY);

////////////////// END ///////////////////

[maverick786us]

I used your code but the application is crashing here it is.

void CGregTestCtrl::OnDraw(
			CDC* pdc, const CRect& rcBounds, const CRect& rcInvalid)
{
	CBitmap bmp;
	bmp.LoadBitmap (IDB_BMP_LOGO);
	pdc->CreateCompatibleDC (pdc);
	pdc->SelectObject (&bmp);
	pdc->BitBlt(120, 100, 161, 183, pdc, 0, 0, SRCCOPY);
}

I think the problem lies over here

pdc->CreateCompatibleDC (pdc);

IDB_BMP_LOGO is the bitmap I imported

[danandu]

I think the problem lies over here

pdc->CreateCompatibleDC (pdc);

IDB_BMP_LOGO is the bitmap I imported[/QUOTE]

Please check the size of the bitmap ur using.

Also u should see compatibility issues as mentioned in msdn:

See the CDC::BitBlt member function for information regarding bit-block transfers between device contexts. To determine whether a device context supports raster operations, see the RC_BITBLT raster capability in the member function

[g_gili]

I used your code but the application is crashing here it is.

void CGregTestCtrl::OnDraw(
			CDC* pdc, const CRect& rcBounds, const CRect& rcInvalid)
{
	CBitmap bmp;
	bmp.LoadBitmap (IDB_BMP_LOGO);
	pdc->CreateCompatibleDC (pdc);
	pdc->SelectObject (&bmp);
	pdc->BitBlt(120, 100, 161, 183, pdc, 0, 0, SRCCOPY);
}

I think the problem lies over here

pdc->CreateCompatibleDC (pdc);

IDB_BMP_LOGO is the bitmap I imported

I think this line is wrong.

pdc->CreateCompatibleDC (pdc);

//Creates a memory device context that is compatible with the device specified by pDC.
So you make compatible the pdc to pdc????

Plese look at an example taken from the MSDN:

void CBlat2View::OnDraw(CDC* pDC)
{
   CBlat2Doc* pDoc = GetDocument();
   ASSERT_VALID(pDoc);

   // load IDB_BITMAP1 from our resources
   CBitmap bmp;
   if (bmp.LoadBitmap(IDB_BITMAP1))
   {
      // Get the size of the bitmap
      BITMAP bmpInfo;
      bmp.GetBitmap(&bmpInfo);

      // Create an in-memory DC compatible with the
      // display DC we're using to paint
      CDC dcMemory;
      dcMemory.CreateCompatibleDC(pDC);

      // Select the bitmap into the in-memory DC
      CBitmap* pOldBitmap = dcMemory.SelectObject(&bmp);

      // Find a centerpoint for the bitmap in the client area
      CRect rect;
      GetClientRect(&rect);
      int nX = rect.left + (rect.Width() - bmpInfo.bmWidth) / 2;
      int nY = rect.top + (rect.Height() - bmpInfo.bmHeight) / 2;

      // Copy the bits from the in-memory DC into the on-
      // screen DC to actually do the painting. Use the centerpoint
      // we computed for the target offset.
      pDC->BitBlt(nX, nY, bmpInfo.bmWidth, bmpInfo.bmHeight, &dcMemory, 
         0, 0, SRCCOPY);

      dcMemory.SelectObject(pOldBitmap);
   }
   else
      TRACE0("ERROR: Where's IDB_BITMAP1?\n");
}

Best regards,
Gili

[maverick786us]

Thanks for the help Gill. It is successfully creating Compitable memory DC. But now the problem is coming in selecting the bitmap into the memory DC. Over here it crashes

CBitmap * pOldBitmap = dcMemory.SelectObject (&bmp);

[g_gili]

Hi maverick786us,


what sample did you used ? In your code? Can you please show your actually code?

Thanks,
Gili

[maverick786us]

Here is the code I have attached. In order to test it you need to register it and then open Micorsoft word>Insert Objects>Greg Digital Sign.

I have also attached the code for registration.

Thanks once again

[g_gili]

Here is the code I have attached. In order to test it you need to register it and then open Micorsoft word>Insert Objects>Greg Digital Sign.

I have also attached the code for registration.

Thanks once again

Hi maverick786us try to use the following code:

void CGregTestCtrl::OnDraw(CDC* pDC, const CRect& rcBounds, const CRect& rcInvalid)
{
	pDC->Rectangle (rcBounds);
	CBitmap bmp;
	CClientDC dc(NULL);
	if (bmp.LoadBitmap (IDB_BMP_LOGO))
	{
		// Get the size of the bitmap
		BITMAP bmpInfo;
		bmp.GetBitmap(&bmpInfo);

		// Create an in-memory DC compatible with the
		// display DC we're using to paint
		CDC dcMemory;
		if ( dcMemory.CreateCompatibleDC(NULL) )
		{
			// Select the bitmap into the in-memory DC
			CBitmap* pOldBitmap = dcMemory.SelectObject(&bmp);


			// Copy the bits from the in-memory DC into the on-
			// screen DC to actually do the painting. Use the centerpoint
			// we computed for the target offset.
			pDC->BitBlt(0, 0, bmpInfo.bmWidth, bmpInfo.bmHeight, &dcMemory, 
				0, 0, SRCCOPY);

			dcMemory.SelectObject(pOldBitmap);
		}
	}
	else
	{
		TRACE ("ERROR: Where's IDB_BITMAP?\n");
	}	
}

Your original example worked in the ActiveX Control Test container utility, but not in MSWord as an object.
The the COleObject has a null m_hWnd this means you can't use the GetClientRect() and also the CreateCompatibleDC(pdc) ( returned NULL ) failed . So use it in this way:

 if ( dcMemory.CreateCompatibleDC(NULL) )
{

.................

}

Best Regards,
Gili

PS:
I'm not to familiar with OLE
Also attached the file where I made the modifications.

[go939]

i know already how to display a bitmap using the resource. i want to know wat if i want to display a bitmap file without the use of resource? just directly from open dialog box.

[golanshahar]

i know already how to display a bitmap using the resource. i want to know wat if i want to display a bitmap file without the use of resource? just directly from open dialog box.

Is your problem is to load the image from file? or get the name from the open dialog box?

Cheers

[sunny_sz]

You have to clarify according to golanshahar's suggestion first. and tell us what exactly you want. in addition, pls. see the below:

BOOL CMyBitmap::LoadBitmap(LPCTSTR szFilename)
{
	ASSERT(szFilename);
	DeleteObject();

	HBITMAP hBitmap = NULL;
	hBitmap = (HBITMAP)LoadImage(NULL, szFilename, IMAGE_BITMAP, 0, 0,
		LR_LOADFROMFILE | LR_CREATEDIBSECTION | LR_DEFAULTSIZE);
	return Attach(hBitmap);
}