I'm implementing a search bar to filter GridView1. I followed this

aspx

<%@ Page Title="" Language="C#" MasterPageFile="~/Manager.Master" AutoEventWireup="true" CodeBehind="ExceptionReport.aspx.cs" Inherits="Bracelet.ExceptionReport" %>

<%@ Register Assembly="Microsoft.ReportViewer.WebForms" Namespace="Microsoft.Reporting.WebForms" TagPrefix="rsweb" %>
<asp:Content ID="Content1" ContentPlaceHolderID="head" runat="server">



</asp:Content>



<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" runat="server">
    <div class="col-md-10">
                    <div class="content-box-large">
                            <div class="panel-heading">
                    <div class="panel-title">Admin Log Report</div>
                </div>

                    <asp:TextBox ID="txtSearch" runat="server" />
            <asp:Button Text="Search" runat="server"/>

                <div class="panel-body">

        <asp:GridView ID="GridView1" runat="server" AllowSorting="True" AutoGenerateColumns="False" DataKeyNames="UserID">
            <Columns>
                <asp:BoundField DataField="UserID" HeaderText="UserID" ReadOnly="True" SortExpression="UserID" />
                <asp:BoundField DataField="UserName" HeaderText="UserName" SortExpression="UserName" />
                <asp:BoundField DataField="UserEmail" HeaderText="UserEmail" SortExpression="UserEmail" />
                <asp:BoundField DataField="logtime" HeaderText="logtime" SortExpression="logtime" />
            </Columns>
        </asp:GridView>
                      </div>
</div>
        <asp:LinqDataSource ID="LinqDataSource2" runat="server" ContextTypeName="Bracelet.BraceletDataContext" EntityTypeName="" TableName="Users">
        </asp:LinqDataSource>
        <asp:LinqDataSource ID="LinqDataSource1" runat="server" ContextTypeName="Bracelet.BraceletDataContext" EntityTypeName="" TableName="Users" Where="UserRole == @UserRole">
            <WhereParameters>
                <asp:Parameter DefaultValue="Admin" Name="UserRole" Type="String" />

            </WhereParameters>
        </asp:LinqDataSource>


    </div>
</asp:Content>

Full code .cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data;
using System.Configuration;
using System.Data.SqlClient;
using System.Text.RegularExpressions;


namespace Bracelet
{
    public partial class ExceptionReport : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            if (!this.IsPostBack)
            {
                this.BindGrid();
            }
        }

        protected void Search(object sender, EventArgs e)
        {
            this.BindGrid();
        }

        private void BindGrid()
        {
            string constr = ConfigurationManager.ConnectionStrings["BraceletConnectionString"].ConnectionString;
            using (SqlConnection con = new SqlConnection(constr))
            {
                using (SqlCommand cmd = new SqlCommand())
                {

                    cmd.CommandText = "SELECT UserID, UserName, UserEmail, logtime FROM [User] WHERE UserID LIKE '%'   @UserID   '%'";

                    cmd.Connection = con;
                    cmd.Parameters.AddWithValue("@UserID ", txtSearch.Text.Trim());
                    DataTable dt = new DataTable();
                    using (SqlDataAdapter sda = new SqlDataAdapter(cmd))
                    {
                        sda.Fill(dt);
                        GridView1.DataSource = dt;
                        GridView1.DataBind();
                    }
                }
            }
        }

        protected void OnPageIndexChanging(object sender, GridViewPageEventArgs e)
        {
            GridView1.PageIndex = e.NewPageIndex;
            this.BindGrid();
        }
    }
}

CodePudding user response：

Not too bad.

but, there are few errors and issues.

first up, you have search button - but it has no "id" assigned.

You probably should get in the habit of simple drag drop the button in from the tool box.

So, we now have this for the button and the grid:

<asp:TextBox ID="txtSearch" runat="server" />
<asp:Button ID="cmdSearch" runat="server" Text="Search" />


<asp:GridView ID="GridView1" runat="server" AllowSorting="True" AutoGenerateColumns="False" DataKeyNames="UserID">
    <Columns>
        <asp:BoundField DataField="UserID" HeaderText="UserID" ReadOnly="True" SortExpression="UserID" />
        <asp:BoundField DataField="UserName" HeaderText="UserName" SortExpression="UserName" />
        <asp:BoundField DataField="UserEmail" HeaderText="UserEmail" SortExpression="UserEmail" />
        <asp:BoundField DataField="logtime" HeaderText="logtime" SortExpression="logtime" />
    </Columns>
</asp:GridView>

NOTE carefull in above, how we gave the button a "ID"

So, our basic code to load up the grid?

FYI: huge love, hugs, high-5's for checking is-post back!!! (always, always do that!!!).

So, our code to load things up can thus look like this:

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


    void BindGrid()
    {
        string constr = ConfigurationManager.ConnectionStrings["BraceletConnectionString"].ConnectionString;

        using (SqlConnection con = new SqlConnection(constr))
        {
            using (SqlCommand cmd = new SqlCommand("SELECT UserID, UserName, UserEmail, logtime FROM [User]", con))
            {

                // optional text box filter (blank = all)
                if (txtSearch.Text != "")
                {
                    cmd.CommandText  = " WHERE UserID LIKE '%'   @UserID   '%'";
                    cmd.Parameters.Add("@UserID", SqlDbType.Text).Value = txtSearch.Text;
                }
                con.Open();
                DataTable dt = new DataTable();
                dt.Load(cmd.ExecuteReader());
                GridView1.DataSource = dt;
                GridView1.DataBind();
                }
            }
        }
    }

Note how we did not need that data adaptor - not needed.

However, we still not created the code stub for the button click (that's why your code is not working - you did not give your button a "id"

So, in the designer - double click on the button. That will create the "event" for you, and jump to the code editor, and we have this:

    protected void cmdSearch_Click(object sender, EventArgs e)
    {
        this.BindGrid();
    }

so, in general - don't type in the "event" stubs for a button - double click on the button - it will create wire it up for you.

Note close, if I flip back to mark-up, the button has become this:

<asp:Button ID="cmdSearch" runat="server" Text="Search" OnClick="cmdSearch_Click" />