Use a PNG as a background image in MFC window - c++

Question

I developed a small program in MFC that can display shapes and move them around.
I would like to be able to select PNG images that can be used as the background of the the main MFC window.
Currently, the background is set to black in the following code:
...
CBrush brush;
brush.CreateSolidBrush(RGB(0,0,0));
myCDC->FillRect(r,&brush);
...
I've found classes that might allow me to upload Bitmaps - for example [CStatic][1] - but have had no luck finding something for PNGs.
Does anyone know how to do this, or have you ever done something similar?

Answer 1

You can try to use the class Image of Gdiplus
http://msdn.microsoft.com/en-us/library/windows/desktop/ms534462(v=vs.85).aspx
because the png file can have the alpha property, but the bitmap does not have,
so I always use the Image to load the png file.
wchar_t szFile[256] = {0}; // png image file path
Image* m_pImage;
m_pImage = new Image(szFile, FALSE); // Load png file
// drawing png image
CPaintDC dc(this); // 用于绘制的设备上下文
Graphics graphics(dc.m_hDC);
if(m_pImage != NULL && (m_pImage->GetLastStatus() == Gdiplus::Status::Ok))
{
graphics.DrawImage(m_pImage, 0, 0, m_pImage->GetWidth(), m_pImage->GetHeight());
}
// need delete it, if you donot need it
if (m_pImage != NULL)
{
delete m_pImage;
m_pImage = NULL;
}

Answer 2

I think that GDI+ is the best and simple way for display images. It supports jpg, gif, tiff as well as png.
You can just display a image as below code,
void OnPaint(HDC hdc)
{
Graphics G(hdc);
Image I(L"snowman.jpg");
if (I.GetLastStatus() != Ok) {
MessageBox(hWndMain,TEXT("cannot read the image file"), TEXT("error"),MB_OK);
return;
}
G.DrawImage(&I,0,0);
}
Also, you can change image during execution time using FromFile static method.
Image *pI;
pI=Image::FromFile(L"snowman.jpg");
G.DrawImage(pI,0,0);
delete pI;