Textbox Validation

akosidandan

Hello, I would like to ask if how do allow 2 input only in a textbox after entering decimal.

Manas Bhardwaj

use regular expression validator and in the validation expression specify this: (^\d*\.\d{2}$)

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akosidandan

Hello, Would you mine if could you give me some sample of using the format validation I have tried using lastindexof but my code doesn't work unless if I enter "." at begginning of my textbox. my code is this

Private Sub TextBox1_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles _
TextBox1.TextChanged

    If TextBox1.Text.IndexOf(".") Then
        TextBox1.MaxLength = Val(TextBox1.TextLength) + 2

    End If

End Sub

Thanks, dfan23

Pete OHanlon

He's already given you the regular expression you need to use. Why haven't you used that? The code you've got here isn't validation, it's input constraint - which is a different thing altogether. What happens if you put in .AA (hint - your code thinks it's valid, but it patently is wrong)?

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akosidandan

Hello, Can I ask again if there would there would be other way. I would like to ask also doesn't that the regular expression check if the input in textbox is as what the expression use? Thanks, dfan23

Laxman Auti

I don't believe on restricting user for inputting. rather i will do it as following. This code will accept user decimal input and after user looses focus of this text box the validation logic will do the stuff for you.

    private void textBox1\_Validating(object sender, CancelEventArgs e)
    {
        decimal result = 0.00M;
        decimal.TryParse(textBox1.Text, out result);
        textBox1.Text = decimal.Round(result, 2).ToString();            
    }

Let me know if you like this.

wrote:

Knock out 't' from can't, You can if you think you can :cool:

Pete OHanlon

If you don't want to use a regular expression check, you could always use a masked edit box and set it to restrict the input.

"WPF has many lovers. It's a veritable porn star!" - Josh Smith

As Braveheart once said, "You can take our freedom but you'll never take our Hobnobs!" - Martin Hughes.

My blog | My articles | MoXAML PowerToys | Onyx