asp.net - web service page System.IndexOutOfRangeException -

public class getareafromcity : system.web.services.webservice {     [webmethod]     public getareabycityid classforgetcity(int city_id)     {         string cs =configurationmanager.connectionstrings["foodinnconnectionstring"].connectionstring;          using (sqlconnection con = new sqlconnection(cs))         {             sqlcommand cmd = new sqlcommand("spgetcitybyid",con);             cmd.commandtype = commandtype.storedprocedure;             sqlparameter parameter = new sqlparameter("@id", city_id);              //to assiate parameter object cmd object             cmd.parameters.add(parameter);             getareabycityid getareabycityid =new getareabycityid();             con.open();             sqldatareader reader = cmd.executereader();              //as weakreference read data wewant tostring retrive column value & polute property city_id values             while (reader.read()){                 getareabycityid.city_id = convert.toint32(reader["city_id"]);                 getareabycityid.area_id =     convert.toint32(reader["area_id"]);              }             return getareabycityid;              //tostring return sql         }     } } 

that's codes service page

public class getareabycityid {     public int ca_id {get;set; }     public int city_id { get; set; }     public int area_id { get; set; } } 

that's class getting area city

create proc [dbo].[spgetcitybyid] @id int  begin select area_id  cities_area city_id = @id end go 

and above database procedure data can retrieve

system.indexoutofrangeexception: city_id @ system.data.providerbase.fieldnamelookup.getordinal(string fieldname) @ system.data.sqlclient.sqldatareader.getordinal(string name) @ system.data.sqlclient.sqldatareader.get_item(string name) @ webapplication1.getareafromcity.classforgetcity(int32 city_id) in c:\users\mudassir\documents\visual studio 2013\projects\webapplication1\webappli

the above error dont know whats problem

your stored procedure returning area_id. code in "while loop" while (reader.read()){ attempting read data 2 columns:

• city_id
• area_id

you add column city_id result set stored procedure query, have value because passing stored procedure parameter.

easiest fix change line:

getareabycityid.city_id = convert.toint32(reader["city_id"]);

to this:

getareabycityid.city_id = city_id;