How to change one character in a string

Question

Hi All,

I am using VB.NET 2019.

I have a Text box control on a form that holds a string, how can I change one character in that string at a specified position using code? For example, suppose the control holds a string of characters like "ABCDE" and I want to change the character at position 4 to an asterisk so that it would then be "ABC*E".

Peter Hibbs.

Answer 1

You can read-modify-write, or try this alternative:

With TextBox1
    If .TextLength >= 4 Then
        .SelectionStart = 3
        .SelectionLength = 1
        .SelectedText = "*"
    End If
End With

Answer 2

Hi Viorel-1

OK, thanks, that works but is this the simplest method to do this? In VBA it can be done with the MID function in one line of code. I would have thought that VB.NET would have something similar, but maybe not! Perhaps it will be possible to build a user defined function which emulates the MID function, I will have to think about it.

Anyway, thanks again.

Peter Hibbs.