Thread: bitmap

LoadBitmap does not expect a filename, but a resource name (the function's name may be confusing, indeed).


If you're using MFC, then first load a bitmap (can be done in the ResourceView), and use it's ID in the LoadBitmap.

{
CBitmap bmp; // Creating CBitmap Object bmp
bmp.LoadBitmap(ID_OF_THE_RESOURCE_BMP);
...
}

Afterwards you can use methods like SetBitmap, SetItemImage, etc. to attach the bitmap to a given control, element (button, treeview, and so on).

Hint:buy Windows programming related books, and forget the old Pascal approach .

Try this out:

CBitmap* aCBmp = NULL;
if(!aCBmp->LoadBitmap("Bitmaps\\bitmap.bmp"))
{
MessageBox("Cannot load bitmap from file","Load error!", MB_OK);
}

Give it a try without pointers.

CBitmap aCBmp;

if(!aCBmp.LoadBitmap("winnt.bmp"))
{

MessageBox("Cannot load bitmap from file","Load error!", MB_OK);
}

"LoadBitmap does not expect a filename, but a resource name "

Right after I said this, made myself the mistake !
Ok, I was wrong .
Now, the *working* code look like this (there are some checkings, too)
/* --------------------------------------------------
loading the bitmap from file and attaching to a CBitmap
--------------------------------------------------*/
CBitmap aCBmp;
HBITMAP hBmp;
BITMAP mBitmap;

FILE *File=NULL; // File Handle
File = fopen("your_bmp_name_here","r");

// file exists?
if ( File )
{
fclose(File);// Close The Handle
MessageBox("File open ok","Open success", MB_OK);

// Load the Bitmap and return a pointer
hBmp = (HBITMAP)::LoadImage( 0, "your_bmp_name_here", IMAGE_BITMAP, 0, 0,
LR_DEFAULTCOLOR |
LR_LOADFROMFILE |// load flags);
LR_CREATEDIBSECTION
);
}

if ( !hBmp )
{
MessageBox("Bitmap load failed","Load error!", MB_OK);
}

if ( !aCBmp.Attach(hBmp) )
{
MessageBox("Attach failed","Error!", MB_OK);
}

if ( !aCBmp.GetBitmap( &mBitmap ) )
{
MessageBox("GetBitmap failed","Error!", MB_OK);
}
}

/* --------------------------------------------------
Put these in the OnPaint event
to display your bmp
--------------------------------------------------*/
void yourClass::OnPaint
{
// do not modify
if (IsIconic())
{
//do not modify
}
else
// your code comes here!
// which loads CBitmap to a memDC, then copies it to the PaintDC

CDC memDC;
CPaintDC dcPaint(this);

if( memDC.CreateCompatibleDC(&dcPaint) )
{
memDC.SelectObject( &aCBmp );

dcPaint.BitBlt( 0, 0,
iYourWidth,
iYourHeight,
&memDC,
0,
0,
SRCCOPY);
}
CDialog::OnPaint();
}
}

You can make a LoadBmp method, this would be more elegant, passing the filename as parameter.

And don't forget to call the DeleteObject function (e.g. in your destructor) to delete each bitmap handle returned by the LoadBitmap function.

Have fun! (and register yourself here, it's a great site)