In this article I will explain with an example, how to implement AJAX Paging in GridView using UpdatePanel in ASP.Net with C# and VB.Net.
 
 
 

Database

Here I am making use of Microsoft’s Northwind Database. You can download it from here.
Download and install Northwind Database
 
 

HTML Markup

The following HTML Markup consists of:
ScriptManager - For enabling AJAX functions.
UpdatePanel – For refreshing the Web Page partially.
ContentTemplate – Defining the content of the UpdatePanel control.
GridView – For displaying data.

Columns

The GridView consists of TemplateField columns.
TemplateField - The TemplateField column consists of ItemTemplate.
 

Events

The GridView has been assigned with OnPageIndexChanging event handlers.
<asp:ScriptManager ID="ScriptManager1" runat="server">
</asp:ScriptManager>
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
    <ContentTemplate>
        <div id="dvGrid" style="width:500px">
            <asp:GridView ID="gvCustomers" runat="server" AutoGenerateColumns="false" AllowPaging="true"
                AllowSorting="true" OnSorting="OnSorting" OnPageIndexChanging="OnPageIndexChanging"
                PageSize="10">
                <Columns>
                    <asp:TemplateField ItemStyle-Width="150px" HeaderText="Customer ID" SortExpression="CustomerID">
                        <ItemTemplate>
                            <%# Eval("CustomerID")%>
                        </ItemTemplate>
                    </asp:TemplateField>
                    <asp:BoundField DataField="ContactName" HeaderText="Contact Name" SortExpression="ContactName" />
                    <asp:BoundField DataField="City" HeaderText="City" SortExpression="City" />
                    <asp:BoundField DataField="Country" HeaderText="Country" SortExpression="Country" />
                </Columns>
            </asp:GridView>
        </div>
    </ContentTemplate>
</asp:UpdatePanel>
 
 

Namespaces

You will need to import the following namespaces.
C#
using System.Data;
using System.Data.SqlClient;
using System.Configuration;
 
VB.Net
Imports System.Data
Imports System.Data.SqlClient
Imports System.Configuration
 
 

Populating GridView from database

Inside the Page Load event of the page, the GridView is populated with records from the Customers table of the Northwind database.
The SortDirection property is a ViewState property which is used to save the Sort Direction of GridView during PostBacks.
Once the DataTable is populated, it is converted into a DataView and then the SortExpression and SortDirection values are used to sort the data.
C#
private string SortDirection
{
    get {return ViewState["SortDirection"] != null ? ViewState["SortDirection"].ToString() : "ASC"; }
    set { ViewState["SortDirection"] = value; }
}
 
protected void Page_Load(object sender, EventArgs e)
{
    if (!this.IsPostBack)
    {
        this.BindGrid();
    }
}
 
private void BindGrid(string sortExpression = null)
{
    string sql = "SELECT CustomerId, ContactName, City, Country FROM Customers";
    string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
    using (SqlConnection con = new SqlConnection(constr))
    {
        using (SqlCommand cmd = new SqlCommand(sql, con))
        {
            using (SqlDataAdapter sda = new SqlDataAdapter())
            {
                sda.SelectCommand = cmd;
                using (DataTable dt = new DataTable())
                {
                    sda.Fill(dt);
                    if (sortExpression != null)
                    {
                        DataView dv = dt.AsDataView();
                        this.SortDirection = this.SortDirection  =="ASC" ? "DESC" : "ASC";
 
                        dv.Sort = sortExpression + " " + this.SortDirection;
                        gvCustomers.DataSource = dv;
                    }
                    else
                    {
                        gvCustomers.DataSource = dt;
                    }
                    gvCustomers.DataBind();
                }
            }
        }
    }
}
 
VB.Net
Private Property SortDirection As String
    Get
        Return IIf(ViewState("SortDirection")IsNot Nothing, Convert.ToString(ViewState("SortDirection")), "ASC")
    End Get
    Set(value As String)
        ViewState("SortDirection") = value
    End Set
End Property
 
Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
    If Not Me.IsPostBack Then
        Me.BindGrid()
    End If
End Sub
 
Private Sub BindGrid(Optional sortExpression As String = Nothing)
    Dim sql As String = "SELECT CustomerId, ContactName, City, Country FROM Customers"
    Dim constr As String = ConfigurationManager.ConnectionStrings("constr").ConnectionString
    Using con As New SqlConnection(constr)
        Using cmd As New SqlCommand(sql, con)
            Using sda As New SqlDataAdapter()
                sda.SelectCommand = cmd
                Using dt As New DataTable()
                    sda.Fill(dt)
                    If sortExpression IsNot Nothing Then
                        Dim dv As DataView = dt.AsDataView()
                        Me.SortDirection = If(Me.SortDirection ="ASC", "DESC", "ASC")
 
                        dv.Sort = sortExpression & " " & Me.SortDirection
                        gvCustomers.DataSource = dv
                    Else
                        gvCustomers.DataSource = dt
                    End If
                    gvCustomers.DataBind()
                End Using
            End Using
        End Using
    End Using
End Sub
 
 

Implementing Paging in GridView

Inside the OnPageIndexChanging event handler, the PageIndex property of the GridView is set with the new PageIndex and the BindGrid method is called.
C#
protected void OnPageIndexChanging(object sender, GridViewPageEventArgs e)
{
    gvCustomers.PageIndex = e.NewPageIndex;
    this.BindGrid();
}
 
VB.Net
Protected Sub OnPageIndexChanging(ByVal sender As Object, ByVal e As GridViewPageEventArgs)
    gvCustomers.PageIndex = e.NewPageIndex
    Me.BindGrid()
End Sub
 
 

Implementing Sorting in GridView

This event handler is executed when a Column is sorted in GridView.
The value of the Sort Expression of the Column which was clicked is present inside the SortExpression property of the GridViewSortEventArgs object and it is passed as parameter to the BindGrid function.
C#
protected void OnSorting(object sender, GridViewSortEventArgs e)
{
    this.BindGrid(e.SortExpression);
}
 
VB.Net
Protected Sub OnSorting(ByVal sender As Object, ByVal e As GridViewSortEventArgs)
    Me.BindGrid(e.SortExpression)
End Sub
 
 

Screenshot

AJAX Paging in GridView using UpdatePanel in ASP.Net
 
 

Demo

View Demo
 
 

Downloads

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