Restricting user input in VB.NET

This blog describes how to restrict the user's input to letters only, numbers only, letters or numbers only, and special characters only.

Letters only

The below code is restricted to allow only text to be entered into the TextBox.

Private Sub TextBox1_KeyPress(ByVal sender As System.Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles TextBox1.KeyPress

If Not Char.IsLetter(e.KeyChar) Then

e.Handled = True

End If

End Sub

Numbers only

The below code is restricted to allow only text to be entered into the TextBox.

Private Sub TextBox1_KeyPress(ByVal sender As System.Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles TextBox1.KeyPress

If Not Char.IsNumber(e.KeyChar) Then

e.Handled = True

End If

End Sub

Letters or numbers only

The below code is restricted to allow Letters or numbers only to be entered into the TextBox special characters are not allowed.

Private Sub TextBox1_KeyPress(ByVal sender As System.Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles TextBox1.KeyPress

If Not Char.IsLetterOrDigit(e.KeyChar) Then

e.Handled = True

End If

End Sub

special characters only

The below code is restricted to allow special characters only to be entered into the TextBox.

Private Sub TextBox1_KeyPress(ByVal sender As System.Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles TextBox1.KeyPress

If Char.IsLetterOrDigit(e.KeyChar) Then

e.Handled = True

End If

End Sub