topic Re: Get Icon from exe in LabWindows/CVI

Get Icon from exe

mevinger — Wed, 05 Apr 2006 19:10:08 GMT

I need to be able to display the icon bitmaps embedded in exe files on a
panel of a CVI application. I am using LabWindows CVI 8.0 base verson.

Can someone help me understand how to do this.

Thanks.......

Re: Get Icon from exe

Wendy L — Thu, 13 Apr 2006 15:57:58 GMT

Hello Michael,

So CVI doesn't provide a built-in function to allow you extract an image from a DLL or EXE. Instead, you will have to use the ExtractIcon(Ex) and DrawIcon functions available in CVI Full Development System and the Windows SDK.

Thanks.

Re: Get Icon from exe

Mert_A. — Fri, 14 Apr 2006 04:45:07 GMT

Michael,

You can also download the Windows Platform SDK directly from Microsoft since you do not have the FDS version of CVI.

Mert A.
National Instruments

Re: Get Icon from exe

Wim S — Tue, 27 Feb 2007 15:07:14 GMT

Hello,

I am also interested in getting the icons from a DLL or EXE file. I have used the ExtractIcon function successfully to get a handle to the icons (HICON). Unfortunately I don't know how to handle HICON variables. Is there any way to turn them into a CVI bitmap, that I can draw to a picture control, canvas or table cell?

Thanks,

Wim

Re: Get Icon from exe

AEDavid — Wed, 28 Feb 2007 22:54:17 GMT

Hi Wim,

The DrawIcon function, mentioned above, will allow you to position your HICON. Otherwise, you would have to use a Windows SDK function to convert from HICON to bitmap - there is no CVI built-in function. The available CVI functions are in Library >> User Interface Library >> Bitmaps. I did not find any Windows SDK functions available to convert an HICON to a bitmap. However, I did see a .NET function Bitmap.FromHicon Method. This method cannot be used directly in CVI, though you could use it for a Measurement Studio project.

Re: Get Icon from exe

Wim S — Thu, 01 Mar 2007 08:28:14 GMT

Hi David,

Thanks for the quick reply. I don't really understand the usage of the first parameter in this DrawIcon function (handle to device context). How can I get the value of this parameter form my picture control?

Re: Get Icon from exe

jr_2005 — Thu, 01 Mar 2007 09:30:56 GMT

You can obtain a system handle from a top level CVI panel with:

    int han;

    GetPanelAttribute (panelHandle, ATTR_SYSTEM_WINDOW_HANDLE, &han);

then you can obtain the Windows DC for the panel by:

    HDC panDC;

    panDC = GetDC ((HWND) han);

which will allow you to use the DrawIcon function, or indeed many other SDK drawing functions. Note that the offsets to the drawing position are with respect to the panel top left corner - you can easily aim the target of your drawing to any part of your panel or control by using suitable offset values.

Re: Get Icon from exe

Wim S — Thu, 01 Mar 2007 21:52:08 GMT

Hello all,

I'm sorry but I can't get this thing working. I use the DrawIcon function, but nothing appears on my panel. Can someone see what I am doing wrong? I attached my project to this message.

Thanks a lot,

Wim

Re: Get Icon from exe

Alex D — Thu, 01 Mar 2007 22:23:18 GMT

The reason you cannot see the result is because of how the CVI panel gets drawn. You are only calling draw icon once, and you are just drawing directly to the screen. This means that the next time the CVI panel redraws, whatever you have drawn will be "covered up" by the new draw. The way to handle this is to redraw whatever you want every time the panel window recieves a WM_PAINT message. You can do this by using InstallWinMsgCallback. I made some quick and dirty modifications to the example you posted that should give you an idea how this is done in CVI. There are some caveats to doing this (CVI isn't really expecting you to be drawing onto the panel) but it does work.

Regards,

-alex

Re: Get Icon from exe

Wim S — Fri, 02 Mar 2007 09:54:44 GMT

Thanks Alex. This seems to work fine. What I would like to do now is save each extracted icon to a PNG file, keeping the icon's transparency. I adjusted my code, trying to get al icon information to create a CVI bitmap. If this would work, then I could simply use the SaveBitmapToPNGFile function. I succeed in getting a handle to the color bitmap and the mask bitmap, using the GetIconInfo function. But then, when trying to get the information from these two bitmaps, the pointer to the data (bmBits member of the BITMAP structure) is always NULL . I already tried a lot of work arounds, but I'm afraid I am stuck here...

Re: Get Icon from exe

Wim S — Fri, 02 Mar 2007 09:56:46 GMT

I thought it might be usefull to attach my code again...

Re: Get Icon from exe

jr_2005 — Fri, 02 Mar 2007 10:11:22 GMT

The example code here manages to draw on a CVI panel without needing to worry about Windows messages. Is this because it draws to an area of the panel occupied by a Canvas control? I have also produced code which draws directly onto a Decoration control with similar ease.

Re: Get Icon from exe

Alex D — Fri, 02 Mar 2007 20:05:36 GMT

Wim:

You should be able to get the bitmap data by calling GetDIBits, similar to the following:

GetDIBits (hdc, iconInfo.hbmColor, 0, bm.bmHeight, bitmapData, &bitmapInfo, DIB_RGB_COLORS);

You basically setup the bitmapInfo structure indicating how you would like the data, and provide the bitmapData buffer, and it will fill it out for you.

JR:

As far as I can tell, the program in the link suffers from the same problems described above. If you force an invalidation by moving the child panel or moving the panel offscreen and back, the draws will be lost. The workaround discussed in this post should work there as well.

Regards,

-alex

Re: Get Icon from exe

Wim S — Mon, 05 Mar 2007 10:05:19 GMT

Thanks a lot Alex, I will try this on my example as soon as I find some spare time . I will let you know about the results.

Re: Get Icon from exe

jr_2005 — Mon, 05 Mar 2007 11:58:53 GMT

Alex,

There might have been a small misunderstanding on my part here. I thought you implied that the area drawn via the DC would be over-written by CVI and would thus never be visible, unless the message based structure for drawing that you suggested was implemented. I find this not to be the case, although of course the area written by the DC is not automatically re-drawn after the panel has been obscured. In my applications, this is not important as the area is constantly being re-written/updated anyway via a CVI Timer mechanism.

Re: Get Icon from exe

MarcelK — Mon, 14 Jan 2013 14:44:59 GMT

I realise this thread is ancient, but as I recently had this problem, too, and all answers thus far were more hacks than anything else, here's a clean solution. The following function extracts the icon of a file and converts it into a CVI bitmap that can be used everywhere without any paint hacks. Enjoy

int GetBitmapFromFileIcon(const char *filename)
{
    int             result = 0;
    SHFILEINFO      fileInfo;
    ICONINFO        iconInfo;
    HICON           hIcon = 0;
    HDC             hDC = 0;
    BITMAPINFO      bmi;
    int             height, width, bmpID;
    unsigned char   *colours = 0;
    unsigned char   *mask = 0;
    unsigned char   *alpha = 0;
    unsigned int    lineLenWin, lineLenCVI;
    unsigned int    x, y, index, indexCVI;
    
    // Request file icon from shell
    memset(&fileInfo, 0, sizeof(fileInfo));
    if (!SHGetFileInfo(filename, 0, &fileInfo, sizeof(fileInfo), SHGFI_ICON | SHGFI_SHELLICONSIZE | SHGFI_SMALLICON)) goto Exit;
    hIcon = fileInfo.hIcon;

    // We need some DC later
    hDC = GetDC(NULL);
    if (!hDC) goto Exit;

    // Get icon components and extract properties
    if (!GetIconInfo(hIcon, &iconInfo)) goto Exit;

    memset(&bmi, 0, sizeof(bmi));
    bmi.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
    if (!GetDIBits(hDC, iconInfo.hbmColor, 0, 0, 0, &bmi, DIB_RGB_COLORS)) goto Exit;
    height = bmi.bmiHeader.biHeight;
    width = bmi.bmiHeader.biWidth;

    // Extract colour values
    colours = malloc(height * width * 4);
    if (!colours) goto Exit;
        
    memset(&bmi, 0, sizeof(bmi));
    bmi.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
    bmi.bmiHeader.biWidth = width;
    bmi.bmiHeader.biHeight = -height;            // "-" for "top down"
    bmi.bmiHeader.biPlanes = 1;
    bmi.bmiHeader.biBitCount = 32;
    bmi.bmiHeader.biCompression = BI_RGB;
    if (!GetDIBits(hDC, iconInfo.hbmColor, 0, height, colours, &bmi, DIB_RGB_COLORS)) goto Exit;

    // Check for alpha channel
    for (index = 3; index < bmi.bmiHeader.biSizeImage; index += 4) {
        if (colours[index]) break;
    }
    
    if (index < bmi.bmiHeader.biSizeImage) {
        // Icon with alpha channel, extract it
        alpha = malloc(height * width);
        if (!alpha) goto Exit;
        
        indexCVI = 0;
        for (index = 3; index < bmi.bmiHeader.biSizeImage; index += 4) {
            alpha[indexCVI++] = colours[index];
        }
    } else {
        // Icon without alpha channel, extract mask
        mask = malloc(height * ((width + 31) & ~31) / 8);
        if (!mask) goto Exit;
        
        bmi.bmiHeader.biBitCount = 1;
        if (!GetDIBits(hDC, iconInfo.hbmMask, 0, height, mask, &bmi, DIB_RGB_COLORS)) goto Exit;

        // Mask is inverted to what CVI expects. Also, it uses different padding (32-bit vs. 16-bit)
        lineLenWin = ((width + 31) & ~31) / 8;
        lineLenCVI = ((width + 15) & ~15) / 8;
    
        index = 0; indexCVI = 0;
        for (y = 0; y < height; y++) {
            for (x = 0; x < lineLenCVI; x++) {
                mask[indexCVI + x] = mask[index + x] ^ 0xff;
            }
            index += lineLenWin;
            indexCVI += lineLenCVI;
        }
    }
    
    if (NewBitmapEx(-1, 32, width, height, 0, colours, mask, alpha, &bmpID)) goto Exit;
    
    result = bmpID;
Exit:
    if (colours)
        free(colours);
    if (alpha)
        free(alpha);
    if (mask)
        free(mask);
    if (hDC)
        ReleaseDC(NULL, hDC);
    if (hIcon)
        DestroyIcon(hIcon);
    return result;
}