c# - How to get Json data in web service without xml and string? -

i'm using angularjs need output data in json format. have tried web service given below getting data database. in wen service i'm getting output xml , string. need without xml , string.

here code:

[webmethod]     public string getdatetimeformats()     {         datatable dt = new datatable();         string strquery = null;         strquery = "sql query";         using (system.data.sqlclient.sqlconnection conn = new system.data.sqlclient.sqlconnection())         {             conn.connectionstring = system.configuration.configurationmanager.appsettings["constr"];             using (system.data.sqlclient.sqlcommand cmd = new system.data.sqlclient.sqlcommand())             {                 cmd.commandtext = strquery;                 cmd.connection = conn;                 conn.open();                 sqldataadapter da = new sqldataadapter(cmd);                 da.fill(dt);                 system.web.script.serialization.javascriptserializer serializer = new system.web.script.serialization.javascriptserializer();                 list<dictionary<string, object>> rows = new list<dictionary<string, object>>();                 dictionary<string, object> row = default(dictionary<string, object>);                 foreach (datarow dr in dt.rows)                 {                     row = new dictionary<string, object>();                     foreach (datacolumn col in dt.columns)                     {                         row.add(col.columnname, dr[col]);                     }                     rows.add(row);                 }                 return serializer.serialize(rows);             }         }     } 

install newtonsoft.json package. , try code.

code

public class helloworlddata     {         public string message;     }      [webmethod]     public void getemployee()     {         javascriptserializer js = new javascriptserializer();         context.response.clear();         context.response.contenttype = "application/json";         helloworlddata data = new helloworlddata();         string sql = "sql_querty";         sqldataadapter da = new sqldataadapter(sql, system.configuration.configurationmanager.appsettings["connection_string"]);         dataset ds = new dataset();         da.fill(ds);         context.response.write(jsonconvert.serializeobject(ds, newtonsoft.json.formatting.indented));     }