Out of memory exception was unhandled

Question

I got an out of memory exception in a photo editor thingy i was making in vb.net. The bitmap image is constantly changing, and I always Dispose() of it after it has been sent off to the other bitmap. Is it being stored in a temp folder and using up all my space on the computer, or what? It always bugs after about 8 bitmaps have been drawn.

How do i fix this?? This is a rather serious issue.

Answer 1

It doesn't sound like 8 bitmaps would be enough to flood your memory. Or are they HUGE bitmaps?

I found that most out of memory exceptions are actually not out of memory exceptions at all, rather they are somehow the result of memory corruption. (I deal with a lot of unmanaged code and PInvokes so this is a rather common thing for me.)

Are you sure you need to Dispose the images? Doesn't the garbage collector automatically dispose of bitmaps?

Answer 2

Disposing has nothing to do with memory. Memory is a managed resource and disposing deals with unmanaged resources, like GDI handles. If you have a global structure like dictionary or something that you add these to and don't remove them, you could be "leaking" references and not allowing the garbage collector to find them.

In these cases it's often tempting to call GC.Collect() to try to clean them up. Know that this won't help you. If the garbage collector were able to clean up the memory, it would. Calling GC.Collect() won't change things if the object you want to collect is still rooted somewhere.

---

Looking at the link in your comments, this might work a little better (adapted from a comment in the link):

''# Crop a bitmap
<Extension()> _
Public Function Crop(ByVal source As Bitmap, _
       ByVal cropX As Integer, ByVal cropY As Integer, _
       ByVal cropWidth As Integer, ByVal cropHeight As Integer) As Bitmap

    ''# parameter checking/guard clauses
    If source Is Nothing Then Throw New ArgumentNullException()

    If cropX > source.Width Then Throw New InvalidArgumentException("cropX")
    If cropY > source.Height Then Throw New InvalidArgumentException("cropY")

    If cropX < 0 Then cropX = 0
    If cropY < 0 Then cropY = 0

    cropWidth = Math.Min(cropWidth, source.Width - cropX)
    cropHeight = Math.Min(cropHeight, source.Height - cropY)

    ''# Create the new bitmap and associated graphics object
    Dim bmp As New Bitmap(cropWidth, cropHeight)
    Using g As Graphics = Graphics.FromImage(bmp)
        ''# Draw the specified section of the source bitmap to the new one
        g.DrawImage(source, New Rectangle(0, 0, cropWidth, cropHeight), cropX, cropY, cropWidth, cropHeight, GraphicsUnit.Pixel)
    End Using

    ''# Return the bitmap
    Return bmp
End Function

I think your problem is elsewhere, but this code is still probably a little nicer.

Answer 3

I am also using GDI32 to scroll images and I get same error after 7 images I also use GC.Collect() but the error is still same please guide me how to solve this problem thank you