how can i change queryString value to (int)

Question

Possible Duplicate:
How can I convert String to Int?

how can i change queryString value to an (int)

string str_id;
str_id = Request.QueryString["id"];
int id = (int)str_id;

Answer 1

Use Int32.TryParse Method to get int value safely:

int id;
string str_id = Request.QueryString["id"];
if(int.TryParse(str_id,out id))
{
    //id now contains your int value
}
else
{
    //str_id contained something else, i.e. not int
}

Answer 2

replace with this one

string str_id;
str_id = Request.QueryString["id"];
int id = Convert.ToInt32(str_id);

or simply and more efficient one

string str_id;
str_id = Request.QueryString["id"];
int id = int.Parse(str_id);

Answer 3

int id = Convert.ToInt32(str_id, CultureInfo.InvariantCulture);

Answer 4

There are several ways you can do that

string str_id = Request.QueryString["id"];

int id = 0;

//this prevent exception being thrown in case query string value is not a valid integer
Int32.TryParse(str_id, out id); //returns true if str_id is a valid integer and set the value of id to the value. False otherwise and id remains zero

Others

int id = Int32.Parse(str_id); //will throw exception if string is not valid integer
int id = Convert.ToInt32(str_id);  //will throw exception if string is not valid integer

Answer 5

you have to use int.Parse(str_id)

Edit : don't trust user input

it's better to check if the input is a number or not before parsing , for this use int.TryParse