Search all column and Highlight in GridView using C# and VB.Net in ASP.Net

Hi tareq24bd,

Check this example. Now please take its reference and correct your code.

Database

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

Download Northwind Database

HTML

Search:<asp:TextBox ID="txtSearch" runat="server" />
<asp:Button Text="Search" runat="server" />
<hr />
<asp:GridView ID="gvCustomers" runat="server" AutoGenerateColumns="false" OnRowDataBound="OnRowDataBound"
    DataSourceID="GridDataSource">
    <Columns>
        <asp:BoundField DataField="Name" HeaderText="Name" />
        <asp:BoundField DataField="City" HeaderText="City" />
        <asp:BoundField DataField="Country" HeaderText="Country" />
    </Columns>
</asp:GridView>
<asp:SqlDataSource ID="GridDataSource" runat="server" ConnectionString="<%$ ConnectionStrings:ConStr %>"
    SelectCommand="SELECT FirstName + ' ' + LastName 'Name',City,Country FROM Employees"
    FilterExpression="Name LIKE '%{0}%' OR City LIKE '%{0}%' OR Country LIKE '%{0}%'">
    <FilterParameters>
        <asp:ControlParameter ControlID="txtSearch" PropertyName="Text" />
    </FilterParameters>
</asp:SqlDataSource>

Namespaces

C#

using System.Text.RegularExpressions;

VB.Net

Imports System.Text.RegularExpressions

Code

C#

protected void OnRowDataBound(object sender, GridViewRowEventArgs e)
{
    if (e.Row.RowType == DataControlRowType.DataRow)
    {
        e.Row.Cells[0].Text = Regex.Replace(e.Row.Cells[0].Text, txtSearch.Text.Trim(), delegate (Match match)
        {
            return string.Format("<span style = 'background-color:#FFFF0C'>{0}</span>", match.Value);
        }, RegexOptions.IgnoreCase);
        e.Row.Cells[1].Text = Regex.Replace(e.Row.Cells[1].Text, txtSearch.Text.Trim(), delegate (Match match)
        {
            return string.Format("<span style = 'background-color:#FFFF0C'>{0}</span>", match.Value);
        }, RegexOptions.IgnoreCase);
        e.Row.Cells[2].Text = Regex.Replace(e.Row.Cells[2].Text, txtSearch.Text.Trim(), delegate (Match match)
        {
            return string.Format("<span style = 'background-color:#FFFF0C'>{0}</span>", match.Value);
        }, RegexOptions.IgnoreCase);
    }
}

VB.Net

Protected Sub OnRowDataBound(ByVal sender As Object, ByVal e As GridViewRowEventArgs)
    If e.Row.RowType = DataControlRowType.DataRow Then
        e.Row.Cells(0).Text = Regex.Replace(e.Row.Cells(0).Text, txtSearch.Text.Trim(),
                                            Function(ByVal match As Match) String.Format("<span style = 'background-color:#FFFF0C'>{0}</span>",
                                                                                            match.Value), RegexOptions.IgnoreCase)
        e.Row.Cells(1).Text = Regex.Replace(e.Row.Cells(1).Text, txtSearch.Text.Trim(),
                                            Function(ByVal match As Match) String.Format("<span style = 'background-color:#FFFF0C'>{0}</span>",
                                                                                            match.Value), RegexOptions.IgnoreCase)
        e.Row.Cells(2).Text = Regex.Replace(e.Row.Cells(2).Text, txtSearch.Text.Trim(),
                                            Function(ByVal match As Match) String.Format("<span style = 'background-color:#FFFF0C'>{0}</span>",
                                                                                            match.Value), RegexOptions.IgnoreCase)
    End If
End Sub

Screenshot