How do I convert a string to an int type in C#?

Question

I am taking a string value from a textbox named txtLastAppointmentNo and I want to convert it to an int and then store it in a database using Linq to sql but I am getting error "input string was not in proper format".

My input string is 2.

My code is:

      objnew.lastAppointmentNo=Convert.ToInt32(txtLastAppointmenNo.Text);

Please point out my mistake.

What value contains txtLastAppointmenNo? And may be you should provide to the Convert.ToInt32() txtLastAppointmenNo.Text ? — Eugene Cheverda
– Eugene Cheverda, Commented Jul 26, 2010 at 7:44
i have written it .text in code but still there is problem..... this error Has made me crazy i dont know whats wrong. there.... :( — Nauman.Khattak
– Nauman.Khattak, Commented Jul 26, 2010 at 8:01
Use the debugger to see what the value of txtLastAppointmentNo.Text actually is. I'm guessing it's not what you think it is - maybe an empty string. — Kent Boogaart
– Kent Boogaart, Commented Jul 26, 2010 at 8:10
Do you have the dot in the string? ie. "2."? or just the 2, ie. "2"? — Lasse V. Karlsen
– Lasse V. Karlsen, Commented Jul 28, 2010 at 9:18

Dustin Laine · Accepted Answer · 2010-07-26 07:45:12Z

14

Assuming you are using WebForms, then you just need to access the textbox value and not the textbox itself:

objnew.lastAppointmentNo = Convert.ToInt32(txtLastAppointmenNo.Text);

Or if you are referencing the HTML control then:

objnew.lastAppointmentNo = Convert.ToInt32(Request["txtLastAppointmenNo"]);

answered Jul 26, 2010 at 7:45

Dustin Laine

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3 Comments

StuartLC Over a year ago

and would recommend some form of validation as well (e.g. Regex Validator)

Nauman.Khattak Over a year ago

sorry i forget type in .Text here in Q. I have done it in code but still there is error.

Dustin Laine Over a year ago

@nonnb +1 for that! @Nauman - Are you setting a breakpoint on that line of code and verifying the input?

Pranay Rana · Accepted Answer · 2010-07-28 09:10:26Z

4

You can also go for int.Parse or int.TryParse or Convert.ToInt32

//int.Parse
int num = int.Parse(text);
//Convert.ToInt32
int num = Convert.ToInt32(text);

//int.TryParse
string text1 = "x";
        int num1;
        bool res = int.TryParse(text1, out num1);
        if (res == false)
        {
            // String is not a number.
        }

edited Jul 28, 2010 at 9:10

answered Jul 26, 2010 at 7:52

Pranay Rana

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Comments

Ahmad Y. Saleh · Accepted Answer · 2013-04-01 20:10:08Z

0

The answer for me was an empty string!

In objnew.lastAppointmentNo=Convert.ToInt32(txtLastAppointmenNo.Text);, txtLastAppointmenNo.Text was an empty value.

edited Apr 1, 2013 at 20:10

Ahmad Y. Saleh

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answered Apr 1, 2013 at 19:48

Thomas Collier

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