DataBind to DropDownList Problem "The IListSource does not contain any data sources"

A

Assimalyst

Hi,

I'm attempting to use a data reader to load data from a single table,
tblCountry, with two columns, countryNo (the Key) and countryName, into
a DropDownList box. Here's the code:


protected System.Data.SqlClient.SqlConnection conn;
protected System.Data.SqlClient.SqlDataReader drCountry;

private void Page_Load(object sender, System.EventArgs e)
{
string SQL = "SELECT * FROM tblCountry";

SqlConnection conn = new
SqlConnection("Server=(local);Database=YLCdbSQL;Integrated
Security=SSPI");
SqlCommand countryLoad = new SqlCommand (SQL, conn);
SqlDataReader drCountry = null;

try
{
conn.Open();
drCountry = countryLoad.ExecuteReader();

countryDropLst.DataSource = drCountry;
countryDropLst.DataMember = "countryName";
countryDropLst.DataTextField = "countryName";
countryDropLst.DataValueField = "countryNo";
countryDropLst.DataBind();
}
finally
{
drCountry.Close();
conn.Close();
}
}



But when I run it I get the error "The IListSource does not contain any
data sources", and the DataBind line is highlighted.

I have checked the table using Enterprise Manager, it exists and has
numerous entries in both columns.

Any idea what the problem might be?

Thanks.
 
A

Assimalyst

Thanks for the ideas,

Removed the datamember, made no difference. Still getting the same
error.

Any more?
 
G

Guest

protected System.Data.SqlClient.SqlConnection conn;
protected System.Data.SqlClient.SqlDataReader drCountry;

private void Page_Load(object sender, System.EventArgs e)

Be sure to add the following

if (!this.IsPostBack)
{

{
string SQL = "SELECT * FROM tblCountry";

SqlConnection conn = new
SqlConnection("Server=(local);Database=YLCdbSQL;Integrated
Security=SSPI");
SqlCommand countryLoad = new SqlCommand (SQL, conn);


try
{
conn.Open();
drCountry = countryLoad.ExecuteReader();
//Try the following:
while(drCountry.Read())
{
ListItem newListItem = new ListItem();

newListItem.Value = drCountry.GetValue(0).ToString();
newListItem.Text = drCountry.GetValue(2).ToString();
// Add Items to DropDownAwardType DropDownList Web Control
countryDropLst.Items.Add(newListItem);
}

//countryDropLst.DataSource = drCountry;
//countryDropLst.DataMember = "countryName";
//countryDropLst.DataTextField = "countryName";
//countryDropLst.DataValueField = "countryNo";
//countryDropLst.DataBind();
}
finally
{
drCountry.Close();
conn.Close();
}
}

}
 
A

Assimalyst

Moojjoo, thankyou so much. I have been struggling with this for far too
long now, at last it works!! :)
 
G

Guest

Hi Assimalyst, I have just noticed that you have been given a solution
creating ListItems manually, if you still want to use databinding you can try
this,
HTH jd


================= into aspx==================
<body>
<form id="Form1" method="post" runat="server">
<asp:dropdownlist id="ddlCountry" runat="server"></asp:dropdownlist></form>
</body>

================ end aspx ======================
================begin code behind=================
using System;
using System.Collections;
using System.ComponentModel;
using System.Configuration;
using System.Data;
using System.Data.SqlClient ;
using System.Drawing;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;

namespace csharp
{
/// <summary>
/// Summary description for WebForm1.
/// </summary>
public class WebForm1 : System.Web.UI.Page
{
protected System.Web.UI.WebControls.DropDownList ddlCountry;

#region Web Form Designer generated code
override protected void OnInit(EventArgs e)
{
//
// CODEGEN: This call is required by the ASP.NET Web Form Designer.
//
InitializeComponent();
base.OnInit(e);
}

/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
private void InitializeComponent()
{
this.Load += new System.EventHandler(this.Page_Load);

}
#endregion


private void Page_Load(object sender, System.EventArgs e)
{
// Put user code to initialize the page here

if(!Page.IsPostBack )
{
bindDropDown();
}
}

private void bindDropDown()
{
//
// get our datareader
//
IDataReader dr = DataAccess.CountryDB.GetCountryReader();

//
// bind our drop down
//
ddlCountry.DataSource = dr;
ddlCountry.DataTextField = "CountryName";
ddlCountry.DataValueField = "CountryNo";
ddlCountry.DataBind ();

//
// close our datareader - note this will also close the database
connection
// because we used ocmd.ExecuteReader(CommandBehavior.CloseConnection)
// when we opened it
//

dr.Close();

}

}

//
// ideally move these classes into a different .cs file / assembly
// so the functionality can be reused in different apps / pages
//
namespace DataAccess
{


//
//class for accessing data relating to country
//

public class CountryDB
{
public static IDataReader GetCountryReader()
{
//should ideally use a stored procedure here
SqlCommand ocmd = new SqlCommand
("Your Select Query Here",
DBConnection.GetDBConnection());
return ocmd.ExecuteReader(CommandBehavior.CloseConnection) ;
}

}

//
// helper class to return a database connection
//

public class DBConnection
{

public static SqlConnection GetDBConnection()
{
//
//ideally use configuration or other more secure store for
connectionstring
//

//SqlConnection oconn = new
SqlConnection(ConfigurationSettings.AppSettings("DBConnectionString")) ;
SqlConnection oconn = new SqlConnection("Your Connection String Here");
oconn.Open();
return oconn;
}
}
}

}
=================end codebehind======================
 
G

Guest

No problem. Now if I could just get an answer to my problem... AGH!!!

Getting values from a user control that was added to a datagrid. This is
driving me batty...
 
A

Assimalyst

Thank you too London Calling, you obviously put quite an effort into
forming your reply, it's much appreciated.

I have implemented your method too, just to see how it works, and i
think i will use it as i will be needing to use the same method on a
number of pages, which your answer allows easily. (no offense Moojjoo!)

Thank you both again, without your suggestions i think i would have
caused my self a serious injury by now banging my head against that
brick wall!! :)
 

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