CellValidating for only can input number

Question

I using this code for validation integer input on datagridview.

private void dataGridView1_CellValidating(object sender, DataGridViewCellValidatingEventArgs e)
{
    if (string.IsNullOrEmpty(e.FormattedValue.ToString()))
    {
        MessageBox.Show("Cannot Empty!");
        e.Cancel = true;
    }
    else if (...)
    {
        MessageBox.Show("Only can input number!");
        e.Cancel = true;
    }
}

and now I have trouble on the code that I put a dots. is there any that can give you an idea ? whether the use regex can be used in these conditions ?

[check if the string is numeric](http://stackoverflow.com/questions/894263/how-do-i-identify-if-a-string-is-a-number) — nlloyd, Jul 01 '16 at 17:26

score 1 · Accepted Answer · answered Jul 01 '16 at 17:32

Just use int.Tryparse and call a method to it, something like this, but I haven't checked this code, just a quick example.

private void dataGridView1_CellValidating(object sender, DataGridViewCellValidatingEventArgs e)
    {
        if (string.IsNullOrEmpty(e.FormattedValue.ToString()))
        {
            MessageBox.Show("Cannot Empty!");
            e.Cancel = true;
        }
        else if (!isNumeric(e.FormattedValue.ToString())
        {
            MessageBox.Show("Only can input number!");
            e.Cancel = true;
        }

    }

Put a method somewhere like this

    public static bool IsNumeric(string theNumber)
    {
        if (theNumber == null) throw new ArgumentNullException("theNumber");

        int n;
        bool isNumeric = int.TryParse(theNumber, out n);
        return isNumeric;
    }

oh sorry! this my fault , it turns out the advice you gave succeed . thanks bro ! — Underdog, Jul 01 '16 at 17:53

score 1 · Answer 2 · answered Jul 01 '16 at 17:33

1

int n;
bool isNumeric = int.TryParse(e.FormattedValue.ToString(), out n);

put this code before your "if" and then check isNumeric in else if block

answered Jul 01 '16 at 17:33

Siavash Rostami

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Thank you for your advice , but still error on !isNumeric – Underdog Jul 01 '16 at 17:43
can you provide the error message? maybe e.FormattedValue is null – Siavash Rostami Jul 01 '16 at 17:45
'!isNumeric' is a 'variable' but is used liked a 'method' – Underdog Jul 01 '16 at 17:47
well of course it's a value, you must use is without parenthesis. it is already calculated – Siavash Rostami Jul 01 '16 at 17:49
I tried to re-code provided @prospector and it worked. I did a little mistake . I 'm sorry for wasting your time . thanks for any advice and answer – Underdog Jul 01 '16 at 17:57
these are basically the same solution, glad you managed to fix it anyway :) – Siavash Rostami Jul 01 '16 at 18:00

CellValidating for only can input number

2 Answers2