What do I have to do to get a bitmap from a png file? Topic is solved

[Ankou]

Because I always get an error, that he couldn't find the file in the rc file.
I don't event know how he should find an image from a string in an resourcefile, I always thought you would need an ID.
And when I'm using wxBITMAP_TYPE_PNG I get an "No Image Handler for type 15 defined"

[tan]

Hi,
AFAIK you can't use PNG files in MS resource files.
I can suggest 3 way:
1. Convert PNG file to BMP
2. Load PNG file on runtime using wxBitamp::LoadFile(...)
3. Convert PNG file to binary data using bin2c:
http://forums.wxwidgets.org/viewtopic.php?t=15176

[Ankou]

you can, you have to choose RCDATA as Ressoucetype(at least when using DX), but how do I get an wxBitmap from it?
But I tried it with LoadFile and then I get those errors.

[tan]

But I tried it with LoadFile and then I get those errors.

Did you call ::wxInitAllImageHandlers() (or wxImage::AddHandler
(new wxPNGHandler())) before?

[idhan]

Hi,

Probably you didn't call these lines:

wxImage::AddHandler(new wxBMPHandler);
wxImage::AddHandler(new wxPNGHandler);

you should do it at the beginning of you application.

[Ankou]

Then I get this problem: http://forums.wxwidgets.org/viewtopic.php?t=18232

[phlox81]

Then you have to link the correct libraries or show us the linker output.

[mc2r]

AFAIK you can't use PNG files in MS resource files.

You can put any file type in a MS resource file.

from one of my projects

Code: Select all

SplashImage PNG "splash.png"

Code to load the png from the ms resource
Note: This is not my code but I forget who to attribute it to. I believe I found it on a thread here or at the wxWidgets wiki. But could be from some random google as well.

Code: Select all

wxMemoryInputStream *GetResourceInputStream(wxString resource_name, wxString resource_type){
	HRSRC hrsrc=FindResource(wxGetInstance(), resource_name, resource_type);
	if(hrsrc==NULL) return NULL;

	HGLOBAL hglobal=LoadResource(wxGetInstance(), hrsrc);
	if(hglobal==NULL) return NULL;

	void *data=LockResource(hglobal);
	if(data==NULL) return NULL;

	DWORD datalen=SizeofResource(wxGetInstance(), hrsrc);
	if(datalen<1) return NULL;

	return new wxMemoryInputStream(data, datalen);
}

bool HasResource(wxString resource_name, wxString resource_type){
	HRSRC hrsrc=FindResource(wxGetInstance(), resource_name, resource_type);
	if(hrsrc==NULL) return false;

	HGLOBAL hglobal=LoadResource(wxGetInstance(), hrsrc);
	if(hglobal==NULL) return false;

	return true;
}

My code for loading the png using the above function

Code: Select all

// create the main application window
    wxMemoryInputStream* stream = GetResourceInputStream(wxT("SplashImage"), wxT("PNG"));
    if(stream != NULL){
		wxImage image(*stream);
		wxBitmap bitmap(image);

		if (bitmap.Ok()){
			 
			wxSplashScreen *splash = new wxSplashScreen(bitmap, wxSPLASH_CENTRE_ON_SCREEN|wxSPLASH_TIMEOUT,
				2000, frame, wxID_ANY, wxDefaultPosition, wxDefaultSize,
				wxBORDER_NONE|wxSTAY_ON_TOP);
			wxYield();

		}
	}

-Max

[tan]

@mc2r:
many thanks for your code