Populate GridView using business class method in ASP.Net

Hi nauna,

You have to return a list and then bind the list to gridview.

Check the below example.

HTML

<asp:GridView ID="gvCustomers" runat="server" AutoGenerateColumns="false">
    <Columns>
        <asp:BoundField DataField="Id" HeaderText="Id" />
        <asp:BoundField DataField="Name" HeaderText="Name" />
        <asp:BoundField DataField="Country" HeaderText="Country" />
    </Columns>
</asp:GridView>

Namespaces

C#

using System.Configuration;
using System.Data.SqlClient;

VB.Net

Imports System.Configuration
Imports System.Data.SqlClient

Code

DataAccess.cs

public class DataAccess
{
    public int Id { get; set; }
    public string Name { get; set; }
    public string Country { get; set; }

    public List<DataAccess> GetCustomers()
    {
        List<DataAccess> Customers = new List<DataAccess>();
        string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
        using (SqlConnection con = new SqlConnection(constr))
        {
            using (SqlCommand cmd = new SqlCommand("SELECT * FROM Customers", con))
            {
                con.Open();
                SqlDataReader sdr = cmd.ExecuteReader();
                while (sdr.Read())
                {
                    Id = Convert.ToInt32(sdr["CustomerId"]);
                    Name = sdr["Name"].ToString();
                    Country = sdr["Country"].ToString();
                    Customers.Add(new DataAccess { Id = Id, Name = Name, Country = Country });
                }
                con.Close();
            }
        }

        return Customers;
    }
}

DataAccess.vb

Public Class DataAccess
    Public Property Id As Integer
    Public Property Name As String
    Public Property Country As String

    Public Function GetCustomers() As List(Of DataAccess)
        Dim Customers As List(Of DataAccess) = New List(Of DataAccess)()
        Dim constr As String = ConfigurationManager.ConnectionStrings("constr").ConnectionString
        Using con As SqlConnection = New SqlConnection(constr)
            Using cmd As SqlCommand = New SqlCommand("SELECT * FROM Customers", con)
                con.Open()
                Dim sdr As SqlDataReader = cmd.ExecuteReader()
                While sdr.Read()
                    Id = Convert.ToInt32(sdr("CustomerId"))
                    Name = sdr("Name").ToString()
                    Country = sdr("Country").ToString()
                    Customers.Add(New DataAccess With {
                        .Id = Id,
                        .Name = Name,
                        .Country = Country
                    })
                End While
                con.Close()
            End Using
        End Using

        Return Customers
    End Function
End Class

Default.cs

protected void Page_Load(object sender, EventArgs e)
{
    if (!IsPostBack)
    {
        DataAccess access = new DataAccess();
        gvCustomers.DataSource = access.GetCustomers();
        gvCustomers.DataBind();
    }
}

Default.vb

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
    If Not IsPostBack Then
        Dim access As DataAccess = New DataAccess()
        gvCustomers.DataSource = access.GetCustomers()
        gvCustomers.DataBind()
    End If
End Sub

Screenshot