Add ASP.Net DataGrid Items to Generic List using C# and VB.Net

Hi Amitabha,

Database

For this example I have used of Northwind database that you can download using the link given below.

Download Northwind Database

Please refer below sample.

HTML

<asp:DataGrid ID="dgvCustomers" runat="server" AutoGenerateColumns="false" >
    <Columns>
        <asp:TemplateColumn>
            <ItemTemplate>
                <asp:CheckBox ID="chkRow" runat="server" />
            </ItemTemplate>
        </asp:TemplateColumn>
        <asp:BoundColumn DataField="CustomerID" HeaderText="ID" />
        <asp:BoundColumn DataField="ContactName" HeaderText="Name" />
        <asp:BoundColumn DataField="Country" HeaderText="Country" />
    </Columns>
</asp:DataGrid>
<br />
<asp:Button ID="btnSearch" runat="server" Text="Search" OnClick="Search" />

Namespaces

C#

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

VB.Net

Imports System.Data
Imports System.Data.SqlClient
Imports System.Configuration

Code

C#

protected void Page_Load(object sender, EventArgs e)
{
    if (!this.IsPostBack)
    {
        this.BindDataGrid();
    }
}

protected void Search(object sender, EventArgs e)
{
    List<CustomerOrder> customers = new List<CustomerOrder>();
    for (int i = 0; i < dgvCustomers.Items.Count; i++)
    {
        DataGridItem gdr = dgvCustomers.Items[i];
        CheckBox chkSelect = ((CheckBox)(gdr.FindControl("chkRow")));
        if (chkSelect.Checked)
        {
            customers.Add(new CustomerOrder
            {
                CustomerID = gdr.Cells[1].Text.Replace("&nbsp;", ""),
                Name = gdr.Cells[2].Text.Replace("&nbsp;", ""),
                Country = gdr.Cells[3].Text.Replace("&nbsp;", ""),
                Orders = this.GetOrders(gdr.Cells[1].Text.Replace("&nbsp;", ""))
            });
        }
    }
}

private void BindDataGrid()
{
    string conString = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
    using (SqlConnection con = new SqlConnection(conString))
    {
        using (SqlCommand cmd = new SqlCommand("SELECT Top 5 * FROM Customers", con))
        {
            con.Open();
            dgvCustomers.DataSource = cmd.ExecuteReader();
            dgvCustomers.DataBind();
            con.Close();
        }
    }
}

private List<Order> GetOrders(string id)
{
    List<Order> orders = new List<Order>();
    string conString = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
    using (SqlConnection con = new SqlConnection(conString))
    {
        using (SqlCommand cmd = new SqlCommand("SELECT TOP 5 OrderID,Freight FROM Orders WHERE CustomerID= @Id", con))
        {
            cmd.Parameters.AddWithValue("@Id", id);
            con.Open();
            SqlDataReader sdr = cmd.ExecuteReader();
            while (sdr.Read())
            {
                orders.Add(new Order
                {
                    OrderID = Convert.ToInt32(sdr["OrderID"]),
                    Freight = Convert.ToDecimal(sdr["Freight"])
                });
            }
            con.Close();
        }
    }

    return orders;
}

public class CustomerOrder
{
    public string CustomerID { get; set; }
    public string Name { get; set; }
    public string Country { get; set; }
    public List<Order> Orders { get; set; }
}

public class Order
{
    public int OrderID { get; set; }
    public decimal Freight { get; set; }
}

VB.Net

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
    If Not Me.IsPostBack Then
        Me.BindDataGrid()
    End If
End Sub

Protected Sub Search(ByVal sender As Object, ByVal e As EventArgs)
    Dim customers As List(Of CustomerOrder) = New List(Of CustomerOrder)()
    For i As Integer = 0 To dgvCustomers.Items.Count - 1
        Dim gdr As DataGridItem = dgvCustomers.Items(i)
        Dim chkSelect As CheckBox = (CType((gdr.FindControl("chkRow")), CheckBox))
        If chkSelect.Checked Then
            customers.Add(New CustomerOrder With {
                .CustomerID = gdr.Cells(1).Text.Replace(" ", ""),
                .Name = gdr.Cells(2).Text.Replace(" ", ""),
                .Country = gdr.Cells(3).Text.Replace(" ", ""),
                .Orders = Me.GetOrders(gdr.Cells(1).Text.Replace(" ", ""))
            })
        End If
    Next
End Sub

Private Sub BindDataGrid()
    Dim conString As String = ConfigurationManager.ConnectionStrings("constr").ConnectionString
    Using con As SqlConnection = New SqlConnection(conString)
        Using cmd As SqlCommand = New SqlCommand("SELECT Top 5 * FROM Customers", con)
            con.Open()
            dgvCustomers.DataSource = cmd.ExecuteReader()
            dgvCustomers.DataBind()
            con.Close()
        End Using
    End Using
End Sub

Private Function GetOrders(ByVal id As String) As List(Of Order)
    Dim orders As List(Of Order) = New List(Of Order)()
    Dim conString As String = ConfigurationManager.ConnectionStrings("constr").ConnectionString
    Using con As SqlConnection = New SqlConnection(conString)
        Using cmd As SqlCommand = New SqlCommand("SELECT TOP 5 OrderID,Freight FROM Orders WHERE CustomerID= @Id", con)
            cmd.Parameters.AddWithValue("@Id", id)
            con.Open()
            Dim sdr As SqlDataReader = cmd.ExecuteReader()
            While sdr.Read()
                orders.Add(New Order With {
                    .OrderID = Convert.ToInt32(sdr("OrderID")),
                    .Freight = Convert.ToDecimal(sdr("Freight"))
                })
            End While
            con.Close()
        End Using
    End Using
    Return orders
End Function

Public Class CustomerOrder
    Public Property CustomerID As String
    Public Property Name As String
    Public Property Country As String
    Public Property Orders As List(Of Order)
End Class

Public Class Order
    Public Property OrderID As Integer
    Public Property Freight As Decimal
End Class

Screenshot