Delay when updating picturebox image

[Raventara]

Hi all,

I have a program which will routinely update the image of a picturebox and resize the picturebox to keep the aspect ratio of the image in tact. The problem I am having is that after about 10 or so changes of the image there is a really long delay in updating the image. The size properties will update but the image itself stays the same. I have tried forcing it to revalidate (even though changing the size of the picturebox does this) and 3 or 4 different ways of loading the image from the file in the first place. I have managed to improve my code so it chews less memory in all this but it's still having a long delay...

Has anyone seen anything like this and if so how do I get around it?

Thanks in advance.

[nukefusion]

Have you checked to make sure that you are disposing of the old images before loading the new one?
A code sample may help.

[Raventara]

That's something I was not doing and I watched the memory get eaten and was exactly what I thought the issue was. I fixed that but it's still happening despite not eating memory up...

        Dim itemno As Integer
 
        itemno = CInt((imagelist.Length) * Rnd())
 
        If Image1.Image IsNot Nothing Then Image1.Image.Dispose()
        Image1.ImageLocation = imagelist(itemno)
        Image1.Load()
 
        Dim ratio As Double
        If Image1.Image.Width >= Image1.Image.Height Then 
            ratio = Image1.Image.Height / Image1.Image.Width 
            Image1.Height = CInt(Image1.Width * ratio)
        Else
            ratio = Image1.Image.Width / Image1.Image.Height 
            Image1.Width = CInt(Image1.Height * ratio)
        End If
 
 

"imagelist" is a string array which contains the images filenames.

I have tried using a temporary Bitmap and loading the image there first and assigning it to the picturebox and have tried using image1.image = image.fromfile(imagelist(itemno)) but neither made a difference.

Thanks.

[Raventara]

Okay, So after some more testing it's not the image loading that is stuffing things up, but the resizing code for the form ("me.width =" and "me.height =") that is doing it...

when I remove the resizing from the code the images change and update just as you would imagine they should, but when I reinstate that code the same thing starts to happen.

Does anyone know why this would happen?

Interestingly it also happens if I set the forms autosize property to Shrink and Grow and let the form autosize itself!!

        Me.Width = 533
        Me.Height = 424
        Image1.Width = 509
        Image1.Height = 400
 
 
 
        Dim ratio As Double
        If Image1.Image.Width >= Image1.Image.Height Then 'imagelist(itemno).Width >= imagelist(itemno).Height Then
 
            ratio = Image1.Image.Height / Image1.Image.Width 'imagelist(itemno).Height / imagelist(itemno).Width
            Image1.Height = CInt(Image1.Width * ratio)
            Me.Height = Image1.Height + 24
        Else
            ratio = Image1.Image.Width / Image1.Image.Height 'imagelist(itemno).Width / imagelist(itemno).Height
            Image1.Width = CInt(Image1.Height * ratio)
            Me.Width = Image1.Width + 24
        End If
        Me.CenterToScreen()