Textbox allows only < 100 & late binding

I have 3 textboxes on my form and each can only contain a number < 100, so I made the following;

Private Sub STH(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles Text1.KeyPress, Text2.KeyPress, Text3.KeyPress

Dim KeyAscii As Integer

KeyAscii = Asc(e.KeyChar)
Select Case KeyAscii
Case 8, 13
Case 48 To 57
If sender.Text.Length > 1 Then
KeyAscii = 0
End If
Case Else
KeyAscii = 0
End Select

If KeyAscii = 0 Then
e.Handled = True
Else
e.Handled = False
End If
End Sub


But I've got option strict on and this gives the error;
Option Strict On disallows late binding.

I can ignore the error message, or remove option strict and it works, but is there a way to fix this?

yep, try this:

VB Code:

Private WithEvents ctl As Control
 
    Private Sub frmComboExample_Activated(ByVal sender As Object, ByVal e System.EventArgs) Handles MyBase.Activated
        Me.ctl = Me.ActiveControl
    End Sub
 
    Private Sub ctl_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles ctl.KeyPress
        Dim tbReference As New TextBox
        If ctl.GetType.Equals(tbReference.GetType) And ctl.Text.Length < 1 Then Exit Sub
 
        Select Case ctl.Name
            Case Me.Text1.Name, Me.Text2.Name, Me.Text3.Name
                Dim KeyAscii As Integer
 
                KeyAscii = Asc(e.KeyChar)
                Select Case KeyAscii
                    Case 8, 13
                    Case 48 To 57
                        If ctl.Text.Length > 1 Then
                            KeyAscii = 0
                        End If
                    Case Else
                        KeyAscii = 0
                End Select
 
                If KeyAscii = 0 Then
                    e.Handled = True
                Else
                    e.Handled = False
                End If
        End Select
    End Sub

Sender is an object, you have to use DirectCast to let the compiler know it will be working with a Textbox.

VB Code:

Dim tbPassedTextBox as TextBox = DirectCast(Sender, TextBox)
 
if tbPassedTextBox.Text.Length > 0 Then ...

The culprit line is Sender.Text.Length, because .Text is not a property of the Object class. All you needed to do was use the above lines of code, no need to change anything else.

Nice catch, I expected it to be the use of multiple object event declarations that the method was handling. The code I provided will work, but this is much simpler and doesn't require such a significant change to his code.

Thanks to both for replies :)

Although I must admit CyberHawke's solution is beyond me (for now :) ) I really like the fact that the list of 'handles' is put inside the procedure, as I have 20 or so textboxes, doesn't affect how things work, just like the way it looks.

I tried converting before I posted this, but then I got the same 'late binding' error, later I discovered;

If CType(sender, TextBox).Text.Length > 4 Then

Reading the help files shows that DirectCast is better (as I'm 100% sure of the type of 'sender'), so I'm going to use that :)

Next piece of code is a textbox that only accepts times (11:12, 19:46 etc. etc.) but I'm gonna look at creating my own textbox control for that one.

I need to add one more method to that code I sent you to make it work correctly

VB Code:

Private Sub ctl_Leave(ByVal sender As Object, ByVal e As System.EventArgs) Handles ctl.Leave
        Me.ctl = Me.ActiveControl
    End Sub

I also found mistakes :blush: in my original code, so it has now been edited and is tested and works

For those who want it, been trying to make a textbox that only accepts a time, the code follows below. But after making it I considered it too much code so I made this, which you execute whenever you want to use the entered time (in my case a button click)

VB Code:

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim EnteredTime As DateTime
 
        Try
            EnteredTime = TimeValue(Textbox1.Text)
        Catch ex As Exception
            MsgBox("You didn't enter a valid time!")
        End Try
 
    End Sub

This is the code from my first try;

VB Code:

Private Sub TimeInTextox(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles TextBox1.KeyPress
 
        Dim KeyAscii As Integer
        Dim StrLength As Integer
 
        StrLength = DirectCast(sender, TextBox).Text.Length
        KeyAscii = Asc(e.KeyChar)
 
        Select Case StrLength
            Case 0
                Select Case KeyAscii
                    Case 48 To 57
                    Case Else
                        KeyAscii = 0
                End Select
            Case 1
                Select Case KeyAscii
                    Case 8, 48 To 58
                    Case Else
                        KeyAscii = 0
                End Select
            Case 2
                Select Case KeyAscii
                    Case 8
                    Case 48 To 57
                        If InStr(DirectCast(sender, TextBox).Text, ":") = 0 Then
                            KeyAscii = 0
                        End If
                    Case 58
                        If InStr(DirectCast(sender, TextBox).Text, ":") <> 0 Then
                            KeyAscii = 0
                        End If
                    Case Else
                        KeyAscii = 0
                End Select
            Case 3
                Select Case KeyAscii
                    Case 8, 48 To 57
                    Case Else
                        KeyAscii = 0
                End Select
            Case 4
                Select Case KeyAscii
                    Case 8
                    Case 48 To 57
                        If DirectCast(sender, TextBox).Text.IndexOf(":") = 1 Then
                            KeyAscii = 0
                        End If
                    Case Else
                        KeyAscii = 0
                End Select
            Case Else
                Select Case KeyAscii
                    Case 8
                    Case Else
                        KeyAscii = 0
                End Select
        End Select
 
        If KeyAscii = 0 Then
            e.Handled = True
        Else
            e.Handled = False
        End If
    End Sub