This is a very simple approach to display PNG files in MFC. Two common libraries provide the needed functionality: zlib and libpng. These libraries are included in the source file.
I had been searching the net for a really simple PNG example for a whole while. But all I found were C files that contained more preprocessor directives than keywords. I don't like preprocessor directives so I've written this example. It uses only one class to do the whole stuff.
Using the code
You might have to upgrade your include-folder settings, because libpng wants to know where your zlib.h is located. After you have unzipped the downloaded archive, you can find this file in the ...\zlib\code\ folder.
The FileOpen handler:
This chunk of code works off both reading and showing the PNG file:
if ( png.load(dlg.GetPathName()) )
int width = png.getWidth();
int height = png.getHeight();
unsigned char* data = png.getBGRA();
if (m_bitmap) delete m_bitmap;
if (m_visible) delete m_visible;
m_bitmap = doCreateCompatibleBitmap(width, height, data, this);
m_visible = doZoomBitmap(m_bitmap, this);
- Reading 1, 2 and 4 bit monochrome images.
- Reading 1, 2 and 4 bit monochrome images with transparency.
- Reading images that use a palette.
- Displaying the
CBitmap object got faster.
- Reading 8-bit RGB images.
- Reading 8-bit RGB images with transparency.
- Reading 8-bit monochrome images.
- Reading 8-bit monochrome images with transparency.