function problem in form

[JohnDW]

I have a problem to write a function.

I want a function that can check if a textbox value is numeric or not. If it is not numeric it gives a message.

My problem is that I want that the function nows witch textbox the user selected.
THere must be a way that the code gives the function the selected textbox and the function gives back
the false or true value to the code.

The following code I use now:

[SIZE=2] [SIZE=2][COLOR=#0000ff][SIZE=2][COLOR=#0000ff]
Private [SIZE=2][COLOR=#0000ff][SIZE=2][COLOR=#0000ff]Function[/COLOR][/SIZE][/COLOR][/SIZE][SIZE=2] Errorcheck() [/SIZE][SIZE=2][COLOR=#0000ff][SIZE=2][COLOR=#0000ff]As[/COLOR][/SIZE][/COLOR][/SIZE][SIZE=2][COLOR=#0000ff][SIZE=2][COLOR=#0000ff]Boolean[/COLOR][/SIZE][/COLOR][/SIZE]
[FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff]Private[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff]Sub[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][FONT=Courier New][SIZE=2] UitKas_LostFocus([/SIZE][/FONT][/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff]ByVal[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][FONT=Courier New][SIZE=2] sender [/SIZE][/FONT][/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff]As[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff]Object[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][FONT=Courier New][SIZE=2], [/SIZE][/FONT][/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff]ByVal[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][FONT=Courier New][SIZE=2] e [/SIZE][/FONT][/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff]As[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][FONT=Courier New][SIZE=2] System.EventArgs) [/SIZE][/FONT][/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff]Handles[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][FONT=Courier New][SIZE=2] UitKas.LostFocus[/SIZE][/FONT][/SIZE][/FONT]
[FONT=Courier New][SIZE=2][FONT=Courier New][SIZE=2]Dim IsError [/SIZE][/FONT][/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff]As[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff]Boolean[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT]
[FONT=Courier New][SIZE=2][FONT=Courier New][SIZE=2]       IsError = Errorcheck() 
[/SIZE][/FONT][/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff]If[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][FONT=Courier New][SIZE=2] IsError = [/SIZE][/FONT][/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff]True[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff]Then[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][FONT=Courier New][SIZE=2]       
  [/SIZE][/FONT][/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff]Exit[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff]Sub[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT]
[FONT=Courier New][SIZE=2][FONT=Courier New][SIZE=2] 
[/SIZE][/FONT][/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff]ElseIf[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][FONT=Courier New][SIZE=2] IsError = [/SIZE][/FONT][/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff]False[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff]Then[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT]
[FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff]
[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][FONT=Courier New][SIZE=2]
UitKas.Text = "0"[/SIZE][/FONT][/SIZE][/FONT][FONT=Courier New][SIZE=2][FONT=Courier New][SIZE=2] UitKas.Focus() 
    
[/SIZE][/FONT][/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff]End[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff]If[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT]
[FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff]
[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT]
[FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff]End[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff]Sub[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT]
[FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff] 
[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/COLOR][/SIZE][/SIZE]

Beneath the Function code:

[FONT=Courier New][SIZE=2][FONT=Courier New][SIZE=2]Private [/SIZE][/FONT][/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff]Function[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][FONT=Courier New][SIZE=2] Errorcheck() [/SIZE][/FONT][/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff]As[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff]Boolean[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT]
[FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff] 
[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][FONT=Courier New][SIZE=2]TextBoxData [/SIZE][/FONT][/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff]As[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff]String[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][SIZE=2][COLOR=#0000ff][SIZE=2][COLOR=#0000ff]

Dim [/COLOR][/SIZE][/COLOR][/SIZE][SIZE=2]TextBoxData =[U] UitKas[/U].Text  ' here I want that the code picks up the selected textbox.value[/SIZE]
[SIZE=2]
[/SIZE][SIZE=2][COLOR=#0000ff][SIZE=2][COLOR=#0000ff]
[/COLOR][/SIZE][/COLOR][/SIZE][SIZE=2]If TextBoxData = [/SIZE][SIZE=2][COLOR=#800000][SIZE=2][COLOR=#800000]""[/COLOR][/SIZE][/COLOR][/SIZE][SIZE=2][COLOR=#0000ff][SIZE=2][COLOR=#0000ff]Then[/COLOR][/SIZE][/COLOR][/SIZE]
[SIZE=2][COLOR=#0000ff][SIZE=2][COLOR=#0000ff]GoTo
[/COLOR][/SIZE][/COLOR][/SIZE][SIZE=2]ex[/SIZE]
[SIZE=2][COLOR=#0000ff][SIZE=2][COLOR=#0000ff] 
Else
[/COLOR][/SIZE][/COLOR][/SIZE][SIZE=2]If IsNumeric(TextBoxData) [/SIZE][SIZE=2][COLOR=#0000ff][SIZE=2][COLOR=#0000ff]Then[/COLOR][/SIZE][/COLOR][/SIZE]
[SIZE=2][COLOR=#0000ff][SIZE=2][COLOR=#0000ff]
[/COLOR][/SIZE][/COLOR][/SIZE][SIZE=2]
Errorcheck = True
[/SIZE]
[SIZE=2][COLOR=#008000][SIZE=2][COLOR=#008000] 
'GoTo ex

[/COLOR][/SIZE][/COLOR][/SIZE][SIZE=2][COLOR=#0000ff][SIZE=2][COLOR=#0000ff]
Else
[/COLOR][/SIZE][/COLOR][/SIZE][SIZE=2]Errorcheck = False
[/SIZE] 
[SIZE=2]MsgBox([/SIZE][SIZE=2][COLOR=#800000][SIZE=2][COLOR=#800000]"You cannot add alpha characters, please input the Integer or numbers !"[/COLOR][/SIZE][/COLOR][/SIZE][SIZE=2], vbCritical)[/SIZE]
[SIZE=2]
[/SIZE][SIZE=2][COLOR=#0000ff][SIZE=2][COLOR=#0000ff]
End If
[/COLOR][/SIZE][/COLOR][/SIZE]
[SIZE=2][COLOR=#0000ff][SIZE=2][COLOR=#0000ff]End If[/COLOR][/SIZE][/COLOR][/SIZE][SIZE=2][COLOR=#0000ff][SIZE=2][COLOR=#0000ff]
[/COLOR][/SIZE][/COLOR][/SIZE][SIZE=2]
ex:

[/SIZE][SIZE=2][COLOR=#0000ff][SIZE=2][COLOR=#0000ff]
Exit Funtion
[/COLOR][/SIZE][/COLOR][/SIZE][SIZE=2][COLOR=#0000ff][SIZE=2][COLOR=#0000ff]End Function[/COLOR][/SIZE][/COLOR][/SIZE]
[SIZE=2][COLOR=#0000ff][SIZE=2][COLOR=#0000ff]
[/COLOR][/SIZE][/COLOR][/SIZE][FONT=Calibri][SIZE=3][FONT=Calibri][SIZE=3]
[/SIZE][/FONT][/SIZE][/FONT]

 

[jmcilhinney]

You're going about this the wrong way. Firstly, you should pretty much never be handling a LostFocus event. If you want to do something when a control loses focus then you pretty much always handle the Leave event. That's not the right choice here though because you don't want the control to lose focus if the data isn't valid. Not surprisingly, the appropriate events to use for validation are Validating and Validated. This is an example of why it's important to read the documentation, so that you know what is available and what it's for. In this case you should be using the Validating event. It's as simple as this:

Private Sub TextBoxes_Validating(sender As Object, e As System.ComponentModel.CancelEventArgs) Handles TextBox2.Validating,
                                                                                                       TextBox1.Validating
    Dim field = DirectCast(sender, TextBox)

    If Not Double.TryParse(field.Text, New Double) Then
        MessageBox.Show("Only numeric data is allowed.", "Invalid Data", MessageBoxButtons.OK, MessageBoxIcon.Error)
        e.Cancel = True
    End If
End Sub

 

[JohnDW]

Allright,

I'm doing it.

Thanks for the suggestion.

John