ASP.Net: Search (Filter) DataTable records without loop using C# and VB.Net

Hi ramco1917,

You need to make use of Linq query.

Please refer below sample.

Note: For this sample i have used temporary DataTable. For more details refer Dynamically create DataTable and bind to GridView in ASP.Net.

HTML

Country:
<asp:TextBox ID="txtCountry" runat="server"></asp:TextBox>
<asp:Button ID="Button1" runat="server" Text="Search" OnClick="Search" />
<hr />
<asp:GridView ID="gvCustomers" runat="server"></asp:GridView>

Namespaces

C#

using System.Data;

VB.Net

Imports System.Data

Code

C#

protected void Page_Load(object sender, EventArgs e)
{
    if (!this.IsPostBack)
    {
        DataTable dt = this.GetData();
        gvCustomers.DataSource = dt;
        gvCustomers.DataBind();
    }
}

protected void Search(object sender, EventArgs e)
{
    string country = txtCountry.Text;
    DataTable dt = this.GetData();
    if (!string.IsNullOrEmpty(country))
    {
        var customers = from customer in dt.AsEnumerable()
                        where customer.Field<string>("Country") == country
                        select new
                        {
                            CustomerId = customer.Field<string>("CustomerId"),
                            Name = customer.Field<string>("Name"),
                            Country = customer.Field<string>("Country")
                        };
        gvCustomers.DataSource = customers;
        gvCustomers.DataBind();
    }
    else
    {
        gvCustomers.DataSource = dt;
        gvCustomers.DataBind();
    }
}

private DataTable GetData()
{
    DataTable dt = new DataTable();
    dt.Columns.AddRange(new DataColumn[3] { new DataColumn("CustomerId"),
                                            new DataColumn("Name"),
                                            new DataColumn("Country") });
    dt.Rows.Add(1, "John Hammond", "United States");
    dt.Rows.Add(2, "Mudassar Khan", "India");
    dt.Rows.Add(3, "Suzanne Mathews", "France");
    dt.Rows.Add(4, "Robert Schidner", "Russia");
    return dt;
}

VB.Net

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load

    If Not Me.IsPostBack Then
        Dim dt As DataTable = Me.GetData()
        gvCustomers.DataSource = dt
        gvCustomers.DataBind()
    End If
End Sub

Protected Sub Search(ByVal sender As Object, ByVal e As EventArgs)
    Dim country As String = txtCountry.Text
    Dim dt As DataTable = Me.GetData()
    If Not String.IsNullOrEmpty(country) Then
        Dim customers = From customer In dt.AsEnumerable() Where customer.Field(Of String)("Country") = country
                        Select New With {Key _
                            .CustomerId = customer.Field(Of String)("CustomerId"), Key _
                            .Name = customer.Field(Of String)("Name"), Key _
                            .Country = customer.Field(Of String)("Country")
                        }
        gvCustomers.DataSource = customers
        gvCustomers.DataBind()
    Else
        gvCustomers.DataSource = dt
        gvCustomers.DataBind()
    End If
End Sub

Private Function GetData() As DataTable
    Dim dt As DataTable = New DataTable()
    dt.Columns.AddRange(New DataColumn(2) {
                        New DataColumn("CustomerId"),
                        New DataColumn("Name"),
                        New DataColumn("Country")})
    dt.Rows.Add(1, "John Hammond", "United States")
    dt.Rows.Add(2, "Mudassar Khan", "India")
    dt.Rows.Add(3, "Suzanne Mathews", "France")
    dt.Rows.Add(4, "Robert Schidner", "Russia")
    Return dt
End Function

Screenshot