CallBack Feature in Asp.Net

CSharp Code Behind

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Data.SqlClient;
public partial class Default2 : System.Web.UI.Page,
System.Web.UI.ICallbackEventHandler
{
private string _callbackResult = null;
protected void Page_Load(object sender, EventArgs e)
{
string cbReference = Page.ClientScript.GetCallbackEventReference(this,
"arg", "GetCustDetailsFromServer", "context");
string cbScript = "function UseCallback(arg, context)" +
"{" + cbReference + ";" + "}";
Page.ClientScript.RegisterClientScriptBlock(this.GetType(),
"UseCallback", cbScript, true);
}
#region ICallbackEventHandler Members
public string GetCallbackResult()
{
return _callbackResult;
}
public void RaiseCallbackEvent(string eventArgument)
{
SqlConnection conn = new
SqlConnection("Data Source=.;Initial Catalog=Northwind;User ID=sa");
SqlCommand cmd = new
SqlCommand("Select * From Customers Where CustomerID = ’" +
eventArgument + "’", conn);
conn.Open();
SqlDataReader MyReader;
MyReader = cmd.ExecuteReader(CommandBehavior.CloseConnection);
string[] MyValues = new string[11];
while (MyReader.Read())
{
MyValues[0] = MyReader["CustomerID"].ToString();
MyValues[1] = MyReader["CompanyName"].ToString();
MyValues[2] = MyReader["ContactName"].ToString();
MyValues[3] = MyReader["ContactTitle"].ToString();
MyValues[4] = MyReader["Address"].ToString();
MyValues[5] = MyReader["City"].ToString();
MyValues[6] = MyReader["Region"].ToString();
MyValues[7] = MyReader["PostalCode"].ToString();
MyValues[8] = MyReader["Country"].ToString();
MyValues[9] = MyReader["Phone"].ToString();
MyValues[10] = MyReader["Fax"].ToString();
}
_callbackResult = String.Join("|", MyValues);
}
#endregion
}