In this article I will explain how to solve the error “The data source does not support server-side data paging” when using GridView with paging enabled in ASP.Net.
 
Database
For this article I am using Customers Table of Microsoft’s Northwind SQL Server database. You can download the Northwind database using the link below.
Download and install Northwind Database
 
Cause
One gets the following error in GridView when he has enabled paging in GridView and tries to bind GridView with a DataSource that does not support paging.
An example of such DataSource is SqlDataReader as it gets records in Forward-Only sequential manner while paging can be done in any order i.e. on Last Page, First page or any intermediate page.
ASP.Net GridView: The data source does not support server-side data paging.
Below is an example code where GridView is populated using SqlDataReader. Now the following code will work until AllowPaging property is set to False. As soon as you set it to true you will get the above exception.
HTML
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="false" AllowPaging="true"
    OnPageIndexChanging="OnPaging">
    <Columns>
        <asp:BoundField DataField="CustomerID" HeaderText="CustomerID" />
        <asp:BoundField DataField="ContactName" HeaderText="ContactName" />
        <asp:BoundField DataField="Country" HeaderText="Country" />
    </Columns>
</asp:GridView>
 
Namespaces
using System.Data;
using System.Configuration;
using System.Data.SqlClient;
 
Code
protected void Page_Load(object sender, EventArgs e)
{
    if (!this.IsPostBack)
    {
        BindGrid();
    }
}
 
private void BindGrid()
{
    string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
    using (SqlConnection con = new SqlConnection(constr))
    {
        using (SqlCommand cmd = new SqlCommand("SELECT CustomerId, ContactName, Country FROM Customers"))
        {
            cmd.Connection = con;
            con.Open();
            using (SqlDataReader sdr = cmd.ExecuteReader())
            {
                GridView1.DataSource = sdr;
                GridView1.DataBind();
            }
            con.Close();
        }
    }
}
 
protected void OnPaging(object sender, GridViewPageEventArgs e)
{
    GridView1.PageIndex = e.NewPageIndex;
    this.BindGrid();
}
 
 
Solution
Solution to this error is making use of DataSources such as Generic List collections, DataTables, DataSets, etc.
The GridView used below is exactly same as the one above, the only difference here is that now it is being populated using a DataTable.
HTML
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="false" AllowPaging="true"
    OnPageIndexChanging="OnPaging">
    <Columns>
        <asp:BoundField DataField="CustomerID" HeaderText="CustomerID" />
        <asp:BoundField DataField="ContactName" HeaderText="ContactName" />
        <asp:BoundField DataField="Country" HeaderText="Country" />
    </Columns>
</asp:GridView>
 
Namespaces
using System.Data;
using System.Configuration;
using System.Data.SqlClient;
 
Code
protected void Page_Load(object sender, EventArgs e)
{
    if (!this.IsPostBack)
    {
        this.BindGrid();
    }
}
 
private void BindGrid()
{
    string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
    using (SqlConnection con = new SqlConnection(constr))
    {
        using (SqlCommand cmd = new SqlCommand("SELECT CustomerId, ContactName, Country FROM Customers"))
        {
            using (SqlDataAdapter sda = new SqlDataAdapter())
            {
                cmd.Connection = con;
                sda.SelectCommand = cmd;
                using (DataTable dt = new DataTable())
                {
                    sda.Fill(dt);
                    GridView1.DataSource = dt;
                    GridView1.DataBind();
                }
            }
        }
    }
}
 
protected void OnPaging(object sender, GridViewPageEventArgs e)
{
    GridView1.PageIndex = e.NewPageIndex;
    this.BindGrid();
}