Reading integer values from a textbox in visual C# 2008

Aleksandar Hristovski

Hi,
I'm a newbie in visual C# and i need to read values from a textbox into an integer variable.
The user is not allowed to input other characters but numbers into the textbox.

            int a1;
            string ia1;
            ia1 = txtMNA1.Text.ToString();
            a1 = Convert.ToInt32(ia1);

This is what i wrote and it returns "Input string was not in a correct format." runtime error.

Thanks for your help,
Hristo

7 Replies

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Jan Montano17y ago
That's odd. Please post more code. Thanks.
Aleksandar Hristovski17y ago
i executed the same code on another computer and it worked, it was a computer specific error after all, sorry for your trouble and thanks for your help.
Aleksandar Hristovski17y ago
This is really confusing, i input 1 into the textbox, the code gets executed and the messagebox says it's not an integer.
so i set a message box to display the string variable ia1 and it returns void, so somehow the contents of the textbox never get copied into the string variable.
i double checked everything and i can't find a problem, so i guess it's a computer specific bug, if you have other suggestions please let me know.
Jan Montano17y ago
int a1;
            string ia1;
            ia1 = textBox1.Text;

            int result;
            if (Int32.TryParse(ia1, out result))
            {
                a1 = Convert.ToInt32(ia1);
                MessageBox.Show(string.Format("Input {0} is an integer", ia1));
            }
            else
            {
                MessageBox.Show(string.Format("Input {0} is not an integer", ia1));
            }
Aleksandar Hristovski17y ago
The textbox can only contain integer values, so i have tried it only with numbers and yet somehow it doesn't work.
I'm thinking of taking the ascii value of the string, subtract 48 out of it and setting the integer to be the result.
However i can't get the ascii of a string, is there function for it?

Thanks,
Hristo
Scott Lysle17y ago
If the value in the textbox is a int, what you have would work. It would not work, for example, if the value contained in the textbox were not an int but rather something like a decimal value.
Blocked Account17y ago
Hi,
Code u have written is working in my end for integer values. because u are converting string value to integer, so u have to take care about the input values.

That error will come if u provide the values like that 123c,12.00 and these values can't be converted into int because now these are string values. So put the validation in the textbox for accepting the integer values.