NumericBox in VB.net

[rekam]

Hellooo!

 

Well, here's the point. Everybody knows what's a TextBox. My goal is to have something like a TextBox, but in which we can only put numbers.

 

I've done a KeyPress method which does all the controls I want, the problem is not here.

 

I'd like to have a component in the ToolBar, which I can drag 'n drop onto the Form, just like a TextBox. But this NumericBox component would have the capacity to accept only numbers.

 

Someone has an idea ? I checked the MSDN documentation and forums too, but I didn't find a single clue....

[Bucky]

What you want to do is create a new Windows Control project.

Go to the code of the control and change it to inherit TextBox

instead of UserControl. Then create a subroutine that overrides

the base class's OnKeyPress event.

 

So, in your component, something like this:

 

Public Overrides Sub OnKeyPress(sender As Object, e As KeyPressEventArgs)

MyBase.OnKeyPress(sender, e) ' Call the base class method

' Add your code here that validates the key press
End Sub

 

Add a Windows Forms project to your solution, then reference

the component project and test it out.

[rekam]

Yeah, ok :) !

 

I tried to do so. It seems that we can't override a KeyPress method, but we can overload it. I really don't the difference, the fact is, in the end, that doesn't work.

 

However, I have build my new component and I succeded in putting it into the toolbar. When I inherits it from a textBox, it takes the properties of the textBox, great :) !

 

But the overload keyPress method I add isn't interpreted by the program. Hum, here's a part of the class :

 

Public Class NumericBox

Inherits System.Windows.Forms.TextBox

 

Public Overloads Sub OnKeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs)

If Me.controleNombre(Me, e) = False Then

e.Handled = True

End If

End Sub

 

Private Function controleNombre(ByVal textBox As System.Windows.Forms.TextBox, ByVal e As System.Windows.Forms.KeyPressEventArgs) As Boolean

Dim estUnNombre As Boolean

estUnNombre = True

If (e.KeyChar < "0" Or e.KeyChar > "9") Then

estUnNombre = False

End If

Return estUnNombre

End Function

 

End Class

 

The function "controleNombre" works well. But even if I put System.Windows.Forms.MessageBox.Show("Hello") in the KeyPress method, nothing happens...Where's the problem ?

[AlexCode]

I think you're complicating this a little bit...

Use this code:

 

Public Class myTextBox
   Inherits System.Windows.Forms.TextBox

#Region " Windows Form Designer generated code "

   Public Sub New()
       MyBase.New()

       'This call is required by the Windows Form Designer.
       InitializeComponent()

       'Add any initialization after the InitializeComponent() call

   End Sub

   'UserControl overrides dispose to clean up the component list.
   Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
       If disposing Then
           If Not (components Is Nothing) Then
               components.Dispose()
           End If
       End If
       MyBase.Dispose(disposing)
   End Sub

   'Required by the Windows Form Designer
   Private components As System.ComponentModel.IContainer

   'NOTE: The following procedure is required by the Windows Form Designer
   'It can be modified using the Windows Form Designer.  
   'Do not modify it using the code editor.
   <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
       '
       'myTextBox
       '
       Me.Name = "myTextBox"

   End Sub

#End Region

   Private Sub myTextBox_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles MyBase.KeyPress
       If Asc(e.KeyChar) < 48 Or Asc(e.KeyChar) > 57 Then
           e.Handled = True
       End If
   End Sub

End Class

[rekam]

Great, really great ! It works at last !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Thank you very much:D

[AlexCode]

Anything else... you know... Just ask :D

[dynamic_sysop]

although you dont need to specify the < 48 and > 57, you could use the inbuilt method that .net hold for the job ;)

   Private Sub TextBox1_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles TextBox1.KeyPress
       If e.KeyChar.IsNumber(e.KeyChar) Then '/// if it's numeric allow it.
           e.Handled = False
       Else
           e.Handled = True
       End If
   End Sub

[AlexCode]

:D I've forgot that...

 

Thanx !

[Volte]

You also have to handle the backspace key. The ASCII code is 8, I believe, so you can use

If Char.IsNumber(e.KeyChar) OrElse KeyChar = Convert.ToChar(8) Then