PNG transparent image on button in Win32 project.

Question

Hi,

Can anybody help me through a code sample which will place an PNG image on a button in Win32 project in vc++ with the help of Gdiplus. The image in resource.

 

Thanks,

Nikhil.

Answer 1

Windows can natively handle bitmaps and icons (you would use SendMessage to send BM_SETIMAGE), if you can do the conversion up front, then that is best (ico files now support png encoding). 

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Microsoft Test - http://tester.poleyland.com/

Answer 2

You can load the PNG from your resource using GDI+ as described here:

http://www.codeproject.com/KB/GDI-plus/cgdiplusbitmap.aspx

Once you have your PNG converted to a CBitmap, you know what to do.

-Seetharam

 

 

Answer 3

Hi,

Thanks for your reply, i think my half work is done but want to ask u some thing. here is my code

Gdiplus::Bitmap* m_pBitmap;

BOOL load =  LoadStdImage(IDB_PNG2, _T("PNG"));    ///Here return value i am getting is true

           // HANDLE hbitmap=     //LoadImage(GetModuleHandle(NULL),m_pBitmap,IMAGE_BITMAP,166,76,LR_DEFAULTCOLOR);
            HWND button= CreateWindow(_T("BUTTON"),_T("Test button"),BS_BITMAP | WS_VISIBLE | WS_CHILD | BS_FLAT,0,0,128,128,hDlg, (HMENU) 5,GetModuleHandle(NULL),NULL);
            ::DWORD dr = ::GetLastError();
            LRESULT lr = SendMessage(button,BM_SETIMAGE,IMAGE_BITMAP,(LPARAM)m_pBitmap);
            dr = ::GetLastError();
            ::Sleep(90);

 

Now i am able to successfully load an image and i am getting some numerical value in the object m_pBitmap. But with sendmessage the LRESULT vale is 0 and getlasterror is also 0. Think there is some problem with calling it.  If u can help me with htis.

The application type is Win32 Windows application. The code is written in WM_initdialog in dialog box class

 

Thanks,

Nikhil.

Answer 4

Hi,

I have resolved the issue of loading the image and send message is also working fine i can see the desired image on the button, but now the problem is with the background. I used PNG image because it was transparent in nature. but what i can see in my dialog is on the back ground image a square button with a border around it and white background . What i except is the button in transparent mode. here is my code,

BOOL load =  LoadStdImage(IDB_PNG3, _T("PNG"));
          if(load == TRUE)
          {
              button= CreateWindow(_T("BUTTON"),_T("TestBACK"),BS_BITMAP | WS_VISIBLE | WS_CHILD | BS_FLAT ,100,100,128,128,hDlg, (HMENU) 7,GetModuleHandle(NULL),NULL);
          ::Gdiplus::Color color;// = ::GetBkColor(pDC);
                color.SetValue(16777215);
                m_pBitmap->
                HBITMAP hbitmap1;
                m_pBitmap->GetHBITMAP(color, &hbitmap1);
            LRESULT lr = SendMessage(button,BM_SETIMAGE,IMAGE_BITMAP,(LPARAM)hbitmap1 );
          }

Thanks,

Nikhil.

Answer 5

Try adding WS_EX_TRANSPARENT to your button style. That will ensure that your button gets a paint message after everything else has been drawn.

 

-Seetharam

Answer 6

Its still not working. Still the same result.

 

Thanks,

Nikhil.

Answer 7

I think that you need CreateWindowEx and also XP styles.

Answer 8

Hi,

have u been able to do it at your end. If yes then can u please give me your code here or email it to me on [e-mail].

 

Thanks,

Nikhil.

Answer 9

Hi,

  Either there is no solution to this problem or i am dumb, because it still doesn't work. My reference to was the following code project link. I think the entire way i have trying needs to change because it seems to me it is not that easy and straight. Thanks for all the efforts given by all u guys.

http://www.codeproject.com/KB/buttons/GdipButton.aspx

Thanks,

Nikhil.

Answer 10

Hi agrawalnikhil,

In fact, you are almost there. We can load the PNG and convert it as the ICON using BitMap::GetHICON. An ICON support transparent originally. Here is the sample code:

 

     Gdiplus::Bitmap* m_pBitmap;

     HICON hicon;

 

     button= CreateWindow(_T("BUTTON"),_T("Test button"),

            BS_ICON | WS_VISIBLE | WS_CHILD ,0,0,128,128,hWnd, NULL,GetModuleHandle(NULL),NULL);

       

       

          m_pBitmap = Gdiplus::Bitmap::FromFile(L"test.png");

 

          m_pBitmap->GetHICON(&hicon);

         

          LRESULT lr = SendMessage(button,BM_SETIMAGE,IMAGE_ICON,(LPARAM)hicon );

 

          ShowWindow(button,SW_SHOW);

 

Cheers,

Yi

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Yi Feng Li [MSFT]
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