CODEWITHSUNDEEP
vb.netvisual-studioparsinginteger
piqto
piqto

Reputation: 3

VB.net validating textbox input for integers crash

I have a form in where users need to input integers to save to an xml when they press a button
the issue lies that when the user does not put in valid input, it displays the error but still attempts to declare the variables for my function and then crashes - how do i stop this?

here's my code:

        If IsNumeric(txtLevel.Text) And IsNumeric(txtHealth.Text) Then
            MsgBox("choose a location to save in")
        ElseIf String.IsNullOrWhiteSpace(txtHealth.Text) Or String.IsNullOrWhiteSpace(txtLevel.Text) Then
            MsgBox("you have not filled in all fields")
            Me.Close()
        Else MsgBox("please input number form")
        End If

        Dim strName As String = txtCharacter.Text
        Dim intLevel As Integer = txtLevel.Text
        Dim intHealth As Integer = txtHealth.Text
        Dim strStat As String = cmbStat.Text

Upvotes: 0

Views: 312

Answers (3)

David
David

Reputation: 6131

You are using quite a few legacy features and you also have Option Strict turned off.

With that being said, your code could look like this:

Dim strName As String = txtCharacter.Text
Dim strStat As String = cmbStat.Text
Dim intLevel, intHealth As Integer

' if either condition is true, close the form prematurely
If (String.IsNullOrWhitespace(txtLevel.Text) OrElse String.IsNullOrWhitespace(txtHealth.Text)) Then
    MessageBox.Show("You have not filled in all fields.", "Invalid Form")
    Me.Close()
ElseIf (Not Integer.TryParse(txtLevel.Text, intLevel) OrElse Not Integer.TryParse(txtHealth.Text, intHealth)) Then
    MessageBox.Show("Please input number form.", "Invalid Form")
    Me.Close()
End If

' continue on with the code

Upvotes: 4

SCDN
SCDN

Reputation: 40

Move your variable declaration inside your "If IsNumeric(txtLevel.Text) And IsNumeric(txtHealth.Text) Then" so its only going to try to assign them the value if both txtLevel and txtHealth are integers.

I would suggest you to change the code like so:

    'Checks if the textboxes are not empty
    If Not String.IsNullOrWhiteSpace(txtHealth.Text) Or String.IsNullOrWhiteSpace(txtLevel.Text) Then
        'They are not empty, so the program checks if they are integers
        If IsNumeric(txtLevel.Text) And IsNumeric(txtHealth.Text) Then
            'The input is integer
            Dim strName As String = txtCharacter.Text
            Dim intLevel As Integer = txtLevel.Text
            Dim intHealth As Integer = txtHealth.Text
            Dim strStat As String = cmbStat.Text

            MsgBox("choose a location to save in")
        Else
            'The input is not integer
            MsgBox("Value is not an integer")
        End If
    Else
        'A textbox is empty
        MsgBox("you have not filled in all fields")
        Me.Close()
    End If

Upvotes: 1

B.S.
B.S.

Reputation: 678

you can try with TryParse to be sure of integer value without error :

Dim intLevel As Integer 
Dim intHealth As Integer 

If (Integer.TryParse(txtLevel.Text, intLevel)) And (Integer.TryParse(txtHealth.Text, intHealth)) Then
                MsgBox("choose a location to save in")
ElseIf String.IsNullOrWhiteSpace(txtHealth.Text) Or String.IsNullOrWhiteSpace(txtLevel.Text) Then
                MsgBox("you have not filled in all fields")
                Me.Close()
Else MsgBox("please input number form")
End If

Dim strName As String = txtCharacter.Text
Dim strStat As String = cmbStat.Text

find more about it on : Int32.TryParse Method

Upvotes: 0

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