asked on

Object reference not set to an instance of an object.

I am trying to populate a dropdown list for my datagrid but keep getting the above error. I know I must be missing something simple but I am new to this and need fast help. Below is my code.
protected void slatergrid_OnItemDataBound(object sender, DataGridItemEventArgs e)
{
// Get the data from DB to populate the DropDownlist
SqlConnection dbConn = null;
SqlCommand dcmd = new SqlCommand();
string strConnection = null;
SqlDataReader drReader = null;
strConnection = System.Configuration.ConfigurationManager.ConnectionStrings["APPLY"].ToString();
dbConn = new SqlConnection(strConnection);
dbConn.Open();
dcmd.Connection = dbConn;
string SQL = "Select * from RPC";
dcmd.Connection = dbConn;
dcmd.CommandText = SQL;
drReader = dcmd.ExecuteReader();
if (drReader.HasRows)
{
while (drReader.Read())
{
if (e.Item.ItemType == ListItemType.AlternatingItem || e.Item.ItemType == ListItemType.Item)
{
// Find the drop down control from datagrid items
DropDownList list = (DropDownList)
e.Item.FindControl("rpc_select");

// Set the text and value properties for the dropdown list to appropriate columns
list.DataTextField = Convert.ToString(drReader["description"]);
list.DataValueField = Convert.ToString(drReader["RPC"]);
list.DataBind();
}
}

}

}

Guy Hengel [angelIII / a3]

on which line does the error occur?
that is essential to debug the problem.

ASKER CERTIFIED SOLUTION

JimBrandley

membership

This solution is only available to members.

To access this solution, you must be a member of Experts Exchange.

Start Free Trial

pallosp

In which line do you get the error message?

I suspect that the SQL query returns records that have NULL values. You should check if the fields equal to DBNull.Value before convering them to string.

Another tip: check if the
DropDownList list = (DropDownList)e.Item.FindControl("rpc_select");
line finds the dropdownlist or returns null.

Is RPC both a table name and a column name?

mbart

ASKER

Sorry, it was on the description line. Added check for null and seems to be working. List is empty but that may be a different issue.