Question

Complete newbie in VS and C#, I am trying to setup a web service, starting by something very simple. I managed to write a class that will (hopefully) return an item’s name, given the item’s code. Now I want to implement this so that it can be called from the web, but I do not know how to retrieve the parameter. The idea is to have http://myurl.com?ProdRef=XYZ, and return the name of product XYZ.
Please don’t shoot, this is my first try with C# and VS !

Edit: working code (for whom it may help)

Class code:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Data;
using System.Data.SqlClient;

/// <summary>
/// Summary description for Class1
/// </summary>
class Product    
    {
        public string ProdRef {get; set; }
        public string ProdName{get; set; }

        public static string GetLabel(string ProdRef)
        {
            //
            // create a new SqlConnection object with the appropriate connection string 
            SqlConnection sqlConn = new SqlConnection("Data Source=ssss;Initial Catalog=ccccc;Persist Security Info=True;User ID=uuu;Password=pppp;Network Library=dbmssocn");
            // open the connection 
            sqlConn.Open();
            // create the command object 
            SqlCommand sqlComm = new SqlCommand("select libelle from dbo.vwArticlesPerm WHERE Ref = '" + ProdRef + "'", sqlConn);
            string strResult = (string)sqlComm.ExecuteScalar();
            // close the connection
            sqlConn.Close();
            return strResult;
        }
    }

Web service code:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Services;

/// <summary>
/// Summary description for WebService
/// </summary>
[WebService(Namespace = "http://xxxxx.lu/clientwebserv")]
[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
// To allow this Web Service to be called from script, using ASP.NET AJAX, uncomment the following line. 
// [System.Web.Script.Services.ScriptService]
public class WebService : System.Web.Services.WebService {

    public WebService () {

        //Uncomment the following line if using designed components 
        //InitializeComponent(); 
    }

    [WebMethod]
    public string GetName(string prName) {
        return Product.GetLabel(prName);
    }

}

Answer 1

I think you should define GetName in this way

[WebMethod]
public string GetName(string name) 
{
    return Product.GetLLabel(name);
}

When a client app loads your WSDL, xml returned shows that GetName function wants a string in input and gives back a string. That’s all.

Next: don’t build queries manually joining strings, int, dates, use Parameters.

SqlCommand sqlComm = new SqlCommand(
    "select libelle from dbo.vwArticlesPerm WHERE Ref = @par", sqlConn);
cmd.Parameters.AddWithValue("@par", ProdRef);

If you want to use GetLabel, you must add public to its declaration or you won’t be able to see it outside its class!

public static string GetLabel(string ProdRef)
{
    string strResult = null;
    using (SqlConnection sqlConn = new SqlConnection("server=xxx;uid=yyy;pwd=zzz;database=myerp;"))
    {
        sqlConn.Open();
        using (SqlCommand sqlComm = new SqlCommand("select libelle from dbo.vwArticlesPerm WHERE Ref = '" + ProdRef + "'", sqlConn))
            strResult = (string)sqlComm.ExecuteScalar();
        sqlConn.Close();
        return strResult;
    }
}

Another advise I give you is to use using(...) when instantiating classes that implements IDisposable interface: when execution exits from using block classes are disposed, so you can avoid memory waste and some headache 🙂