Solved

How to restrict a negative value in a textbox

Posted on 2011-09-27
5
318 Views
Last Modified: 2012-05-12
How can I only allow positive values in my textbox? I want the user to only enter positive numbers. How can I flag them?
0
Comment
Question by:cmdolcet
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
5 Comments
 
LVL 25

Expert Comment

by:Luis Pérez
ID: 36709205
Put this code in the KeyPress event for the text box:

        If Not (Char.IsDigit(e.KeyChar) Or Char.IsControl(e.KeyChar)) Then
            e.Handled = True
        End If


Hope that helps.
0
 
LVL 17

Expert Comment

by:sonawanekiran
ID: 36709233
Private Sub TextBox1_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles TextBox1.KeyPress

' textbox1 just accept numeric data

If Char.IsNumber(e.KeyChar) Then

e.Handled = False

Else

MessageBox.Show("plz click numbers only")

e.Handled = True

End If

End Sub
0
 

Author Comment

by:cmdolcet
ID: 36709244
OK that works for any negative number but when I try to enter a 0.6 it will not allow my to enter the .
0
 
LVL 70

Expert Comment

by:Éric Moreau
ID: 36709253
0
 
LVL 17

Accepted Solution

by:
sonawanekiran earned 125 total points
ID: 36709280
Try this

Private Sub TextBox1_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles TextBox1.KeyPress

    Dim allowedChars As String = "0123456789."

    If allowedChars.IndexOf(e.KeyChar) = -1 Then
        ' Invalid Character
        e.Handled = True
    End If

End Sub
0

Featured Post

[Live Webinar] The Cloud Skills Gap

As Cloud technologies come of age, business leaders grapple with the impact it has on their team's skills and the gap associated with the use of a cloud platform.

Join experts from 451 Research and Concerto Cloud Services on July 27th where we will examine fact and fiction.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Article by: jpaulino
XML Literals are a great way to handle XML files and the community doesn’t use it as much as it should.  An XML Literal is like a String (http://msdn.microsoft.com/en-us/library/system.string.aspx) Literal, only instead of starting and ending with w…
If you're writing a .NET application to connect to an Access .mdb database and use pre-existing queries that require parameters, you've come to the right place! Let's say the pre-existing query(qryCust) in Access takes a Date as a parameter and l…
Monitoring a network: why having a policy is the best policy? Michael Kulchisky, MCSE, MCSA, MCP, VTSP, VSP, CCSP outlines the enormous benefits of having a policy-based approach when monitoring medium and large networks. Software utilized in this v…
Visualize your data even better in Access queries. Given a date and a value, this lesson shows how to compare that value with the previous value, calculate the difference, and display a circle if the value is the same, an up triangle if it increased…

615 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question