Validating a Textbox to numeric

[peterhinett]

Hello. I have a text box but I only want users to be able to enter numbers and not text. Could anyone help me with the code. Thanks

[jamesd0142]

Function IsNumeric(ByVal MyVal)
        Dim i As Integer
        Dim a As String
        Dim MyValLen As String
        MyValLen = Len(MyVal)
        If MyValLen > 0 Then
            For i = 1 To MyValLen
                a = Mid(MyVal, i, 1)
                If a <> "0" Then 'Or a <> "1" Or a <> "2" Then
                    If a <> "1" Then
                        If a <> "2" Then
                            If a <> "3" Then
                                If a <> "4" Then
                                    If a <> "5" Then
                                        If a <> "6" Then
                                            If a <> "7" Then
                                                If a <> "8" Then
                                                    If a <> "9" Then
                                                        Return False
                                                        Exit Function
                                                    End If
                                                End If
                                            End If
                                        End If
                                    End If
                                End If
                            End If
                        End If
                    End If
                End If
            Next
            Return True
        End If
    End Function
 

use this function like:

if isnumeric(textbox2.text) = true then
'code here
end if
 

[kadghar]

use this function like:

if isnumeric(textbox2.text) = true then
'code here
end if
 

another way could be using the ascii code, something like:

public function isnumeric(byval str1 as string) as boolean
isnumeric = true
i=1
do
    j= asc(str1,i,1)
    if (j < 48 or j > 59) and j <> 46 then
        isnumeric = false
        exit do
    end if
    i = i + 1
loop until i > len(str1)
end function

number 46 is for a dot, so you'll also acept decimals

Im not that familiarized with vbnet, but in other versions of vb IsNumeric is an existing function, you dont have to create it.

[lotus18]

Check this:

http://www.thescripts.com/forum/thread736290.html

Use this function at keypress event of the textbox.

[Killer42]

You might also consider using the Masked Edit control rather than a textbox. The masked edit control gives you more control over the input.

[Mohan Krishna]

Check this:

http://www.thescripts.com/forum/thread736290.html

Use this function at keypress event of the textbox.

Hi

It is very good! And I wrote it several times in many projects!

ALL THE BEST!

[lotus18]

Hi

It is very good! And I wrote it several times in many projects!

ALL THE BEST!

Thanks for the acknowledgment : )

[VEnkatramasamy]

hi,
use the Keypress or keydown event

check for the ascii value range 48-57, if yes then make
keycode=0
or keypress=false

hope this will help you,

With regards
Venkatramasamy SN

[dontbe]

You use this to only number can accept by a Textbox
1. Declare this API at You Declration Section (in your form/module):

'&& Only Allowing Number In Texttbox
Public Declare Function GetWindowLong Lib "user32"  Alias "GetWindowLongA" (ByVal hWnd As Long, ByVal nIndex As Long) As Long
 
Public Declare Function SetWindowLong Lib "user32" Alias    "SetWindowLongA" (ByVal hWnd As Long, ByVal nIndex As Long, ByVal dwNewLong As Long) As Long
 
 

2. Create Private or Public sun in fom/module, use this code:

Public Sub SetNumber(NumberText As TextBox, Flag As Boolean)
Dim curstyle As Long
Dim newstyle As Long
 
    curstyle = GetWindowLong(NumberText.hWnd, GWL_STYLE)
 
    If Flag = True Then
       curstyle = curstyle Or ES_NUMBER
    Else
       curstyle = curstyle And (Not ES_NUMBER)
    End If
 
    newstyle = SetWindowLong(NumberText.hWnd, GWL_STYLE, curstyle)
    NumberText.Refresh
End Sub
 

3. And then you call that sun in any event, as example:

Public Sub Form_Load()
       SetNumber textBox1, True
End Sub
 

Hope this work for you, i think it more simple than using a lot of loops..

[lotus18]

Hope this work for you, i think it more simple than using a lot of loops..

You created an API function where in fact you can do this with more simple code