Gridview not populating while using a While() structure. C# ASP.Net

I am having problems with this grid view. I am populating it with a query. However, it will not populate or even appear if I use a while(reader.Read()) structure. Without the while structure, it works fine. However, I need to access two specific fields. The code is below.

 SqlDataReader myReader;
 try
 {
     using (myConnection)
     {
         myConnection.Open();
         ArrayList arrliGames = new ArrayList();
         myReader = myCommand.ExecuteReader();

         decimal decTicketCost = 0;
         int intTicketCount = 0;

         while (myReader.Read ())
         {
             decTicketCost = Convert .ToDecimal (myReader ["TicketCost"]);
             intTicketCount =Convert .ToInt32 (myReader ["NumTickets"]);
         }

         //Binds listbox
         grdEvents.DataSource = myReader ;
         grdEvents.DataBind();
     }
 }

Answers:

Thank you for visiting the Q&A section on Magenaut. Please note that all the answers may not help you solve the issue immediately. So please treat them as advisements. If you found the post helpful (or not), leave a comment & I’ll get back to you as soon as possible.

Method 1

The SqlDataReader is forward-only. When you first iterate over the rows, there is “nothing left” in it to display afterwards.

I suggest that you use the reader to populate a strongly-typed list in memory, and then bind the GridView to the list instead. Example:

var myList = new List<TicketInfo>();
while (myReader.Read())
{
    myList.Add(new TicketInfo
    {
        TicketCost = Convert.ToDecimal(myReader["TicketCost"]),
        NumTickets = Convert.ToInt32(myReader["NumTickets"])
    });
}
grdEvents.DataSource = myList;
grdEvents.DataBind();

The code example above assumes that you have a class called TicketInfo defined as:

class TicketInfo
{
    public decimal TicketCost { get; set; }
    public int NumTickets { get; set; }
}

If you haven’t used generics (such as List<TicketInfo> in the example) before, I suggest you do some reading on the subject.

Method 2

create a class with two properties
1. decTicketCost
2. intTicketCount

now in while loop create instance and assign the value to the object properties

and add it in a list.

Finally bind the list.

Method 3

I guest you have set datasource to myList instead myReader

grdEvents.DataSource = myList;

Edit: You need to add other column in your list object.

while (myReader .Read ())
{
//myList-- Add other columns you need to display in the gridview
//As I don't know the your Data Reader column, I can't give you exact mylist object

 myList.Add(new TicketInfo{TicketCost = Convert.ToDecimal(myReader["TicketCost"]),NumTickets = Convert.ToInt32(myReader["NumTickets"])  });
}

Method 4

You could replace

while (myReader .Read ())                        
{                             
decTicketCost  = Convert .ToDecimal (myReader ["TicketCost"]);                            intTicketCount = Convert .ToInt32 (myReader ["NumTickets"]);                             
}                              
//Binds listbox                         
grdEvents.DataSource = myReader ;                         
grdEvents.DataBind();

to
grdEvents.DataSource = myReader ;
grdEvents.DataBind();

And then the gridview for some values

hope this help

Method 5

replace the following line

grdEvents.DataSource = myReader;

with

grdEvents.DataSource = myList;

Method 6

How about this:

using (myConnection)
{
   myConnection.Open();
   DataSet ds = myCommand.ExecuteDataSet();

   //Binds listbox
   grdEvents.DataSource = ds;
   grdEvents.DataBind();                    
}
ForEach (DataRow dr in ds.tables[0].rows)
    myList.Add(new TicketInfo{TicketCost = Convert.ToDecimal(myReader["TicketCost"]),NumTickets = Convert.ToInt32(myReader["NumTickets"])  });

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