Validating KeyPress

I wish to Validate entry in a textbox so that only uppercse text is entered. If Lowercase text i sentered I wish to convert it automatically to uppercase.

In vb6 - I could use the keypress event with keyascii.

For example - to convert to uppercase.

VB Code:

If KeyAscii >= 97 And KeyAscii <= 122 Then
            KeyAscii = KeyAscii - 32
         End If

Looking at .net - I can do something similar,

VB Code:

Private Sub txtJobCode_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles txtJobCode.KeyPress
      If e.KeyChar.IsLower(e.KeyChar) Then
         e.KeyChar.ToUpper(e.KeyChar)
      End If
 
   End Sub

but I can't figure out how to reset the key that was pressed (The above example, doesnt change what was entered in the text box).

any ideas?

well i ran into the same type of problem, but if all you want to do is change the text to upper case do this after they tab away or in the changetext event because the keychar, keycode, keyascii object are read only so you cant change them

Code:

---

txtTest.Text = txtTest.Text.ToUpper

---

easy, just set the e.Handled to true and the system will discard the KeyPress...
for example this would block the user from entering the character c:

VB Code:

Private Sub TextBox1_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles TextBox1.KeyPress
        If e.KeyChar = "c" Then e.Handled = True
    End Sub

... hmm now that I re-read your post I'm not sure if this is what you actually meant :rolleyes:

Thanks for the replies jop and ender_pete

I did it as ender_pete suggested in the end (in the textchanged event), although I found I had to save the position of the selectionstart property and reset it afterwards.

VB Code:

Dim intX As Int32 = txtJobCode.SelectionStart
      txtJobCode.Text = txtJobCode.Text.ToUpper()
      txtJobCode.SelectionStart = intX

Jops suggetion was useful for disallowing any character that isn't a Letter or Backspace...

VB Code:

If Not e.KeyChar = ControlChars.Back Then
         If Not e.KeyChar.IsLetter(e.KeyChar) Then
            Beep()
            e.Handled = True
         End If
      End If

Thanks guys

there's also a new property for textboxes called CharacterCasing
it can be set to normal, upper or lower.

if set to upper, the textbox will automatically change lower case letters to uppercase

Thanks Nina,

I should have known there was an easy .Net way of doing it.