Image Array

You could place the images into an imagelist, assign the imagelist to the imagelist property of the button and then assign the images to the button using the index or key value from the list.  You may still programmatically add, access, and remove images form the image list using the ImageList.Images.Add method, for example:

Add an image:
ImageList1.Images.Add(99, Image.FromFile("C:\Temp\SomeImage.jpg"))

Remove an image:
ImageList1.Images.RemoveAt(99);

Set a button to use an image (with the image list already assigned to the button):
Button1.ImageIndex = 4