System.InvalidOperationException in Application designer.vb

[Inferrd]

Hi Rocky,

You already have a variable named nudFSize
It references a NumericUpDown control on your Form.

You really do not want to be declaring the variable again as an Integer type (with the line Dim nudFSize As Integer)

If you want to set the Value property of the NUD, you would use:

nudFSize.Value = 24

If you want to read the Value property of the NUD, you would use:

Dim Fsize as Integer = CInt(nudFSize.Value)

However, you would not do that in the ValueChanged event handler in the manner you have it in your code:

Private Sub nudFSize_ValueChanged(sender As Object, e As EventArgs) Handles nudFSize.ValueChanged
    Dim nudFSize As Integer
    Dim FSize As Integer = Cint(nudFSize.Value)
End Sub

Variables have scope. As soon as you exit that method any variable you declare in the method will be lost and unretrievable. Take a look at the documentation here for starters.