Home / Community & Support / Knowledge Base / RadControls for WinForms / Editors (TextBox, MaskedEdit, DateTimePicker) / Creating numeric textbox

Creating numeric textbox

Article Info

Rating: 5

Article information

Article relates to

 RadTextBox and RadSpinEditor for WinForms

Created by

 Angel Kanchev, Telerik

Last modified

 February 15, 2008

Last modified by

 Angel Kanchev

 
HOW-TO
Create a numeric textbox that accepts numbers only

SOLUTION
There are 2 ways to create a textbox that accepts numbers only:

  • Use RadSpinEditor and make it look like a normal textbox. The benefit of using this approach is that there are additional features in RadSpinEditor such as the modification of the numbers with Step using the MouseWheel and the functionality given by ThousandsSeparator, Hexadecimal, Maximum and Minimum properties.
    Here are the steps to do this:
    1. Drag RadSpinEditor into the form area
    2. In the Action List choose "Edit UI elements"
    3. In the dialog tree select the BoxLayout that is just under the DockLayoutPanel. For that BoxLayout, set the Visbility property to Collapsed.
    4. RadSpinEditor will decrease its height, since spin buttons' height is no longer being calculated. Therefore, you should set the top Padding of the RadSpinElement to 2 and the bottom Padding to 3.
       
  • Use RadTextBox and customize it by handling its TextChanging event. Here's a short code snippet illustrating the above approach in both C# and Visual Basic:

    C#:
    private void radTextBox1_TextChanging(object sender, TextChangingEventArgs e)
    {
        e.Cancel = !IsNumber(e.NewValue);
    }
    private bool IsNumber(string text)
    {
        bool res = true;
        try
        {
            if (!string.IsNullOrEmpty(text) && ((text.Length != 1) || (text != "-")))
            {
                Decimal d = decimal.Parse(text, CultureInfo.CurrentCulture);
            }
        }
        catch
        {
            res = false;
        }
        return res;
    }

    Visual Basic:
    Private Sub radTextBox1_TextChanging(ByVal sender As Object, ByVal e As TextChangingEventArgs)  
        e.Cancel = Not IsNumber(e.NewValue)  
    End Sub  
     
    Private Function IsNumber(ByVal text As String) As Boolean  
        Dim res As Boolean = True 
     
        Try  
            If Not String.IsNullOrEmpty(text) AndAlso ((text.Length <> 1) OrElse (text <> "-")) Then  
                Dim d As Decimal = Decimal.Parse(text, CultureInfo.CurrentCulture)  
            End If  
        Catch  
            res = False 
        End Try  
     
        Return res  
    End Function 

Comments

If you'd like to comment on this KB article, please, send us a Support Ticket.
Thank you!

Please Sign In to rate this article.