VB.NET 中的仅字母文本框

Question

How would you write a regular expression in Visual Basic .NET to only accept upper and lower case letters on button click?

My text box can't accept numbers, blank spaces, or special characters.

Answer 1

In order to forbid a user type anything but letters into a text box field, just add the KeyPress event for your TextBox:

Private Sub TextBox1_KeyPress(sender As Object, e As KeyPressEventArgs) Handles TextBox1.KeyPress
    If e.KeyChar <> vbBack And Char.IsLetter(e.KeyChar) = False Then
        e.Handled = True
    End If
End Sub

Char.IsLetter is checking if the character typed is a letter. If the character the user typed is not a letter ( = False ), we omit passing it to the field by setting e.Handled to True .