SmallChange and LargeChange properties of scrollbars

These properties apply to scrollbar controls in WinForms, but the concepts are pretty universal:

  • SmallChange is the change in value that occurs when you click on a scrollbar’s arrows
  • LargeChange is the change in value that occurs when you click on a scrollbar’s track
  • I had some vague ideas on how to set these values, but this MSDN entry confirmed by suspicions that the values should be set relative to size of the container and not the size of the content.

    User interface guidelines suggest that the SmallChange and LargeChange properties are set relative to the size of the view that the user sees, not to the total size including the unseen part. For example, if you have a picture box with scroll bars displaying a large image, the SmallChange and LargeChange properties should be set relative to the size of the picture box, not to the size of the image.