Search into Textbox and Bind Gridview using Asp.net

Textbox search to bind record on text changed ,google type textbox search,bind grid using google type textbox search

Design page for Gridview and textbox

<div>
    Enter first name to search:
</div>
<div>
    <asp:TextBox ID="txtSearch" runat="server" AutoPostBack="true" OnTextChanged="txtSearch_TextChanged">
    </asp:TextBox>&nbsp;
</div>
<div>
    <asp:UpdatePanel ID="updatepanel1" runat="server">
        <ContentTemplate>
            <asp:GridView ID="grdSearch" runat="server" AutoGenerateColumns="false">
                <Columns>
                    <asp:TemplateField HeaderText="Employee Id">
                        <ItemTemplate>
                            <asp:Label ID="lblFirstName" runat="server" Text='<%# Highlight(Eval("emp_id").ToString()) %>'>
                            </asp:Label>
                        </ItemTemplate>
                    </asp:TemplateField>
                    <asp:TemplateField HeaderText="Employee First Name">
                        <ItemTemplate>
                            <asp:Label ID="lblLastName" runat="server" Text='<%#(Eval("emp_first_name")) %>'></asp:Label>
                        </ItemTemplate>
                    </asp:TemplateField>
                    <asp:TemplateField HeaderText="Employee Middle Name">
                        <ItemTemplate>
                            <asp:Label ID="lblLocation" runat="server" Text='<%#(Eval("emp_middle_name")) %>'></asp:Label>
                        </ItemTemplate>
                    </asp:TemplateField>
                    <asp:TemplateField HeaderText="Employee Last Name">
                        <ItemTemplate>
                            <asp:Label ID="lblLocation" runat="server" Text='<%#(Eval("emp_last_name")) %>'></asp:Label>
                        </ItemTemplate>
                    </asp:TemplateField>
                    <asp:TemplateField HeaderText="Employee Name">
                        <ItemTemplate>
                            <asp:Label ID="lblLocation" runat="server" Text='<%#(Eval("emp_name")) %>'></asp:Label>
                        </ItemTemplate>
                    </asp:TemplateField>
                </Columns>
            </asp:GridView>
        </ContentTemplate>
        <Triggers>
            <asp:AsyncPostBackTrigger ControlID="txtSearch" EventName="TextChanged" />
        </Triggers>
    </asp:UpdatePanel>
</div>

Code for this page

string strConnection = "Data Source=BITPLUS3\\SqlExpress;Initial Catalog=HRDB;User ID=sa;pwd=bit123";

//ConfigurationManager.AppSettings["WebHRConnectionString"];

protected void Page_Load(object sender, EventArgs e)
{

    if (!IsPostBack)
    {
     //   BindGrid();
    }
}

private DataTable GetRecords()
{
    SqlConnection conn = new SqlConnection(strConnection);
    conn.Open();
    SqlCommand cmd = new SqlCommand();
    cmd.Connection = conn;
    cmd.CommandType = CommandType.Text;
    cmd.CommandText = "Select emp_id, emp_first_name, emp_middle_name,emp_last_name, emp_name from tblemployee";
    
    SqlDataAdapter dAdapter = new SqlDataAdapter();
    dAdapter.SelectCommand = cmd;
    DataSet objDs = new DataSet();
    dAdapter.Fill(objDs);
    return objDs.Tables[0];

}
private void BindGrid()
{
    DataTable dt = GetRecords();
    if (dt.Rows.Count > 0)
    {
        grdSearch.DataSource = dt;
        grdSearch.DataBind();
    }
}
private void SearchText()
{
    DataTable dt = GetRecords();
    DataView dv = new DataView(dt);
    string SearchExpression = null;
    if (!String.IsNullOrEmpty(txtSearch.Text))
    {
        SearchExpression = string.Format("{0} '%{1}%'",
        grdSearch.SortExpression, txtSearch.Text);

    }
    
    dv.RowFilter = "emp_name like" + SearchExpression;
    grdSearch.DataSource = dv;
    grdSearch.DataBind();

}
public string Highlight(string InputTxt)
{
    string Search_Str = txtSearch.Text.ToString();
    // Setup the regular expression and add the Or operator.
    Regex RegExp = new Regex(Search_Str.Replace(" ", "|").Trim(),
    RegexOptions.IgnoreCase);

    // Highlight keywords by calling the 
    //delegate each time a keyword is found.
    return RegExp.Replace(InputTxt,
    new MatchEvaluator(ReplaceKeyWords));

    // Set the RegExp to null.
    RegExp = null;
}

public string ReplaceKeyWords(Match m)
{
    return "<span class=highlight>" + m.Value + "</span>";
}

protected void txtSearch_TextChanged(object sender, EventArgs e)
{
    SearchText();
}