VB Code:
Dim formResized As Boolean
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
formResized = False
End Sub
Private Sub Form1_Resize(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.Resize
formResized = True
End Sub
Private Sub Form1_MouseEnter(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.MouseEnter
If formResized = True Then
MessageBox.Show("Form was resized")
Me.Width = Me.Height
formResized = False
End If
End Sub