Things to watch out for when moving from VB 3.0 to VB 4.0
Two things to watch out for when upgrading from Visual Basic 3.0 to Visual Basic 4.0:

  • Form_Resize was often used to re-arrange controls, depending on the size of the form. Old VB3 code used to move each control around one-by-one, then calls DoEvents to allow them to actually move on the screen. You may now find an unpleasant screen effect where the controls appear to jiggle about one-by-one, or even move in a "Rook's Move". The solution is careful use of the .Visible properties.
  • The Err variable is now an object with many properties, and a default property that allows backwards compatibility. It's pretty compatible, but you no longer have the same VB3 implicit clear-on-read behaviour, having a .Clear method instead.