如何处理System.OverflowException

Question

I have one simple windows application in that amount Textbox is there. When i enter amount into amount textbox it will convert it to words in another textbox named txtrupees . Amount Textbox field maximum length is set to 11 places in that last 3 places .00.

My problem is now when i Enter amount with .00 it is working fine. But if i enter 11 places it will giving following Error:

System.OverflowException' occurred in mscorlib.dll Value was either too large or too small for an Int32.tried following code.

How can I prevent this kind of error?

private void txtamount_TextChanged(object sender, EventArgs e)
{
    if (txtamount.Text != string.Empty)
    {
        string[] amount = txtamount.Text.Split('.');
        if (amount.Length == 2)
        {
            int rs, ps;
            int.TryParse(amount[0], out rs);
            int.TryParse(amount[1], out ps);

            string rupees = words(rs);
            string paises = words(ps);
            txtrupees.Text = rupees + " rupees and " + paises + " paisa only ";
        }
        else if (amount.Length == 1)
        {
            string rupees = words(Convert.ToInt32(amount[0]));
            txtrupees.Text = rupees + " rupees only";
        }
    }
}

Answer 1

The issue comes from Convert.ToInt32(amount[0]) where amount[0] can be almost anything, including being superior to Int.MaxValue or inferior to Int.MinValue which would cause an overflow.

Use int.TryParse(amount[0], out foo); and use foo :

else if (amount.Length == 1)
{
    int ps;
    if(int.TryParse(amount[0], out ps))
    {
        string rupees = words(ps);
        txtrupees.Text = rupees + " rupees only";
    }
    else
        txtrupees.Text = "Invalid number";
}

If you want to deal with bigger numbers, you can use Int64 , Double or Decimal

Answer 2

a number that has 11 places is larger than a Int32 number. I suggest you should use int64 instead of int32 https://msdn.microsoft.com/en-us/library/29dh1w7z.aspx