Bitmaps, APIs, PictureBoxes = Frustrating

Hey all. I've been beating this thing over and over, and I still don't know what's occuring.

I'm trying to get my function to load up an entire bitmap image within the space of the picturebox (ie: a thumbnail.) So far, I've been able to get the image into the box, but I can't figure a way around the color appearance. When I load a 24-bit bmp, it still displays it like a 8-bit! How do I fix this?

Here's the code I'm using (at the moment):

VB Code:

Public Function DisplayBMP(picBox As PictureBox, fileName As String) As Boolean
    Dim hDC As Long, hBMP As Long
    Dim fileNo As Integer, counter As Integer
    Dim imgSize As POINT
            
    DisplayBMP = False
    
    fileNo = FreeFile
    Open fileName For Binary As fileNo
        Get #fileNo, 19, imgSize
    Close fileNo
        
    counter = 0
    Do
        hDC = CreateCompatibleDC(picBox.hDC)
        counter = counter + 1
    Loop While hDC < 1 Or counter < 15
    
    If hDC < 1 Then
        MsgBox "Failed on Device Context creation"
        Exit Function
    End If
    
    hBMP = LoadImage(0, fileName, IMAGE_BITMAP, 0, 0, LR_LOADFROMFILE Or LR_DEFAULTSIZE)
    If hBMP = 0 Then
        DeleteDC hDC
        MsgBox "Failed to load the image"
        Exit Function
    End If
    
    SelectObject hDC, hBMP
    DeleteObject hBMP
            
    StretchBlt picBox.hDC, 0, 0, picBox.Width, picBox.Height, hDC, 0, 0, imgSize.X * 15, imgSize.Y * 15, vbSrcCopy
    
    picBox.Refresh
 
    DeleteDC hDC
 
End Sub

Any help on how to fix my color problem, or on how to better implement this, is greatly appreciated.

Destined

Why don't you just load the image straight into an IPictureDisp and then use StretchBlt straight from there ?

If you want a simplier way, you can use an Image control, it has a property that automatically stretches the image to its own size.

As to your code, everything seems to be fine with it, I have no idea why it shows up in 256 colors.

We are of course assuming you're using a resolution of greater than 256 colours in windows :)

You need to use SetStretchBltMode and pass it COLORONCOLOR, I believe - otherwise it looks 256-color. You could also just use LoadImage, that function can do resizing at load.

As I said, he should just get the image into an IPictureDisp and Blit from there.
Use a generateDC() function.

LoadImage uses bi-linear filtering ;)

Whatever :)

If you use a GenerateDC() function though you end up with a reusable device context, and its very easy to use once you have a working GenerateDC()

Thanx everyone for the help. :)

plenderj
I think I just want to use pure API calls to get it working. For what it's worth, that was how I originally did it, but the colors didn't seem to come out right. And, yes, I am running in more than 256 colors. :)

Janus
Excellent, this worked great. I just added the following code:

VB Code:

...
    DeleteObject hBMP
    
    SetStretchBltMode picBox.hDC, COLORONCOLOR  ' This works!
    StretchBlt picBox.hDC, 0, 0, picBox.Width, picBox.Height, hDC, 0, 0, imgSize.x * 15, imgSize.y * 15, vbSrcCopy
    
    picBox.Refresh
    ...