Search GridView using TextBox TextChanged event in ASP.Net

Thanks for your response, but i dont want textbox to be inside grideview just like your example said. i want to have a textbox saparate from gridview.

Hi Micah ,its so simple . try my code 

use Northwind ms sql  database .

Html Code

<div>
        <script type="text/javascript">
            function RefreshUpdatePanel() {
                __doPostBack('<%= Code.ClientID %>', '');
      };
</script>
        <asp:ScriptManager ID="ScriptManager1" runat="server"></asp:ScriptManager>
 
    Search:<asp:TextBox ID="Code" runat="server"    onkeyup="RefreshUpdatePanel();"  placeholder="Search Whole Product..." AutoPostBack="true" OnTextChanged="Code_TextChanged"></asp:TextBox>


     <asp:UpdatePanel ID="Update" runat="server">
        <ContentTemplate>
           
      <asp:GridView ID="gvCustomers"  runat="server" ShowHeader="false"  CssClass="table table-bordered" 
                RowStyle-CssClass="rowHover"     AutoGenerateColumns="false" 
                 >
               
    <Columns>
     
        <asp:TemplateField >
                            <ItemTemplate>


                               <asp:Label ID="lblid" Font-Bold="true" runat="server" Text=' <%#Eval("ProductID") %>' ></asp:Label>
                                      
                                    
                         
                             
                            </ItemTemplate>



                        </asp:TemplateField>
       <asp:TemplateField >
                            <ItemTemplate>


                              <asp:Label ID="lblname" Font-Bold="true" runat="server" Text=' <%#Eval("ProductName") %>' ></asp:Label>
                                      
                                    
                         
                             
                            </ItemTemplate>



                        </asp:TemplateField>
        <asp:TemplateField >
                            <ItemTemplate>


                           
                                      
                                 <asp:Label ID="lblmrp"  Font-Bold="true"  runat="server" Text=' <%#Eval("QuantityPerUnit") %>' ></asp:Label>
                             
                            </ItemTemplate>



                        </asp:TemplateField>
        

    </Columns>
</asp:GridView>
  
             </ContentTemplate>
        <Triggers>
            <asp:AsyncPostBackTrigger ControlID="Code" />
        </Triggers>
    </asp:UpdatePanel>
        </div>

c# code 

Namespace

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

code on textbox changeed event 

 protected void Code_TextChanged(object sender, EventArgs e)
    {

        if (Code.Text != "")
        {

            SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["ErpConnection"].ConnectionString);
            conn.Open();
            SqlCommand cmd = new SqlCommand("Select *   from Products where [ProductName] LIKE @SearchTerm1 + '%'", conn);
            cmd.Parameters.AddWithValue("@SearchTerm1", Code.Text.Trim());
            SqlDataAdapter adp = new SqlDataAdapter(cmd);
            DataSet ds = new DataSet();
            adp.Fill(ds);
            gvCustomers.Visible = true;
            gvCustomers.DataSource = ds;
            gvCustomers.DataBind();
            gvCustomers.Focus();

            Code.Focus();

        }
        else
        {

            gvCustomers.Visible = false;
            Code.Focus();

        }

    }