asp.net c# GridView select does no action-CodePudding

why GridView1_SelectedIndexChanged not working?

i'm learning asp.net on my own(which means i learn through youtube) , using vs2015

created a grid of items and want to show the selected item in a textbox , but code doesn't do any change

i created empty project added masterpage and default page , and just added a text and grid , scriptmanager updatepanel contenttemplate. whenever i click select on any row from the grid textbox is still empty

MasterPage.master:

<%@ Master Language="C#" AutoEventWireup="true" CodeFile="MasterPage.master.cs" Inherits="MasterPage" %>

<!DOCTYPE html>

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
    <asp:ContentPlaceHolder id="head" runat="server">
    </asp:ContentPlaceHolder>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <asp:ContentPlaceHolder id="ContentPlaceHolder1" runat="server">
        
        </asp:ContentPlaceHolder>
    </div>
    </form>
</body>
</html>

Default.aspx:

<%@ Page Title="" enableeventvalidation="true" Language="C#" MasterPageFile="~/MasterPage.master" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>

<asp:Content ID="Content1" ContentPlaceHolderID="head" Runat="Server">
    <style type="text/css">
        .auto-style1 {
            width: 100%;
        }
    </style>
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" Runat="Server">

    <asp:ScriptManager ID="ScriptManager1" runat="server">
    </asp:ScriptManager>
    <asp:UpdatePanel ID="UpdatePanel1" runat="server">
        <ContentTemplate>
            <table >

                <tr>
                    <td>
                        <asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
                    </td>
                    
                </tr>
                <tr>
                    <td>&nbsp;</td>
                    <td>&nbsp;</td>
                </tr>
                <tr>
                    <td>
                        <asp:GridView ID="GridView1" runat="server" OnSelectedIndexChanged="GridView1_SelectedIndexChanged">
                            <Columns>
                                <asp:CommandField ButtonType="Button" ShowSelectButton="True" />
                            </Columns>
                        </asp:GridView>
                    </td>
                    
                </tr>
            </table>

        </ContentTemplate>
    </asp:UpdatePanel>
</asp:Content>

Default.aspx.cs:

using System;
using System.Data;
public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            DataTable tbl = new DataTable();
            tbl.Columns.Add("serial");

            for (int i = 0; i < 4; i  )
            {
                DataRow row = tbl.NewRow();
                row[0] = i   1;
                tbl.Rows.Add(row);
            }
            GridView1.DataSource = tbl;
            GridView1.DataBind();
        }
        
    }
    protected void GridView1_SelectedIndexChanged(object sender, EventArgs e)
    {
        TextBox1.Text = GridView1.SelectedRow.Cells[0].Text;
    }

}

CodePudding user response：

You are selecting the wrong cell on the SelectedIndexChanged method.

The first Cell (index 0) contains the button, so you want the second cell (index 1).

You should place a breakpoint on the method and see for yourself what other properties are filled in the GridView.