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VB.NET Discussion Thread
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Oct 3rd, 2008

validate user input

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Hi all,
I have different text boxes the I need to validate the user inut. The code that I have (example) does work, the problem is that if there is absolutly nothing in the text box I don't want to get the error message. If I have a starting "0", physically in the text box, or "non-numeric value" then I do want the error message. What happens is when I "clear" everything in the boxes then I get the error also but don't want it if nothing is in the boxes.

VB.NET Syntax (Toggle Plain Text)
Private Sub txtInterestRate_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles txtInterestRate.TextChanged
        Try
 
            If Me.txtInterestRate.Text.Length = 0 Then          'reads interest rate text box
                Me.errInput.SetError(Me.txtInterestRate, "Please Enter a valid value") 'if 0 gives error
 
            ElseIf Not IsNumeric(txtInterestRate.Text) Then     'checks input for numeric value
                Me.errInput.SetError(Me.txtInterestRate, "Please Enter a valid Numeric value") 'if non-numerics gives error
                Throw New Exception("Please enter a valid numeric value")
 
            ElseIf txtInterestRate.Text = 0 Then                'checks input for numeric value
                Me.errInput.SetError(Me.txtLoanAmount, "Please Enter a Non Zero valid Numeric value") 'if non-numerics gives error
                Throw New Exception("Please enter a valid Non Zero numeric value")
 
            End If
 
        Catch ex As Exception       'exception handeler for error input
            MsgBox(ex.Message)      'displays error
            Me.txtInterestRate.Text = ("")
        End Try
    End Sub
Private Sub txtInterestRate_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles txtInterestRate.TextChanged
        Try

            If Me.txtInterestRate.Text.Length = 0 Then          'reads interest rate text box
                Me.errInput.SetError(Me.txtInterestRate, "Please Enter a valid value") 'if 0 gives error

            ElseIf Not IsNumeric(txtInterestRate.Text) Then     'checks input for numeric value
                Me.errInput.SetError(Me.txtInterestRate, "Please Enter a valid Numeric value") 'if non-numerics gives error
                Throw New Exception("Please enter a valid numeric value")

            ElseIf txtInterestRate.Text = 0 Then                'checks input for numeric value
                Me.errInput.SetError(Me.txtLoanAmount, "Please Enter a Non Zero valid Numeric value") 'if non-numerics gives error
                Throw New Exception("Please enter a valid Non Zero numeric value")

            End If

        Catch ex As Exception       'exception handeler for error input
            MsgBox(ex.Message)      'displays error
            Me.txtInterestRate.Text = ("")
        End Try
    End Sub

Any help would really be appreciated!
Thanks,
Ken

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tyserman5674

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Oct 3rd, 2008

Re: validate user input

What about right after Try inserting

If Me.txtInterestRate.Text <> ""
/// do all of your stuff
End If

rapture

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Posting Whiz in Training

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Oct 4th, 2008

Re: validate user input

rapture,
Thank you very much for your reply. I added your line of code to all the text boxes and it worked great.
Thanks,
Ken

tyserman5674

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Oct 7th, 2008

Re: validate user input

Hi All,

I have been trying to figure out another problem with this program, maybe some one can help me out.
I need some type of code so if the text field is left completey empty it will give an error and tell the user to please input a number.
I just haven't been able to figure it out.

Help Please,
Ken

tyserman5674

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Oct 7th, 2008

Re: validate user input

You may want to check that when user presses Ok-button (or any similar button):

VB.NET Syntax (Toggle Plain Text)
Private Sub cmdOk_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdOk.Click
  ' Check empty text
 
  If Me.txtInterestRate.Text.Trim = "" Then
    MessageBox.Show("Please enter interest rate", _
      "Missing Information", _
      MessageBoxButtons.OK, _
      MessageBoxIcon.Warning)
    Me.txtInterestRate.Focus() ' Set focus to field if you want
  End If
 
End Sub
Private Sub cmdOk_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdOk.Click
  ' Check empty text

  If Me.txtInterestRate.Text.Trim = "" Then
    MessageBox.Show("Please enter interest rate", _
      "Missing Information", _
      MessageBoxButtons.OK, _
      MessageBoxIcon.Warning)
    Me.txtInterestRate.Focus() ' Set focus to field if you want
  End If

End Sub

or "integrate" this with rapture's answer:

VB.NET Syntax (Toggle Plain Text)
If Me.txtInterestRate.Text <> ""
  /// do all of your stuff
Else
  MessageBox.Show("Please enter interest rate", _
     "Missing Information", _
     MessageBoxButtons.OK, _
     MessageBoxIcon.Warning)
End If
If Me.txtInterestRate.Text <> ""
  /// do all of your stuff
Else
  MessageBox.Show("Please enter interest rate", _
     "Missing Information", _
     MessageBoxButtons.OK, _
     MessageBoxIcon.Warning)
End If

Teme64

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Oct 8th, 2008

Re: validate user input

Teme64,
Thank you for your input, it works great now. I just couldn't figure that one out.
Thanks,
tyserman5674

tyserman5674

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This thread is more than three months old

No one has posted to this discussion for at least three months. Please let old threads die and do not reply to them unless you feel you have something new and valuable to contribute that absolutely must be added to make the discussion complete. Otherwise, please start a new thread in this forum instead.

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