如何在asp.net中配置数据列表的索引？

Question

I develop a web application in visual studio that display rooms pictures and their names from the database in one page and a rate button beside each room all in a datalist 我在Visual Studio中开发了一个Web应用程序，该应用程序可以在一页中显示数据库中的房间图片及其名称，并在数据列表中每个房间旁边显示一个速率按钮。

Then when the user click the rate button the room picture and its name should be transfered to the rate page but , 然后，当用户单击“费率”按钮时，房间图片及其名称应被转移到费率页面，但是，

What happens with me is that if I click any button only the first room picture and name displayed in the rate page :'( ! 对我来说，发生的事情是，如果我单击任何按钮，则仅显示房价页面上显示的第一张房间图片和名称：

I think it corresponds with the index of the datalist , but I don't know how to deal with it !! 我认为它与数据列表的索引相对应，但是我不知道如何处理它！

What should I do to fix it ? 我该怎么解决？

Here is the code 这是代码

webform1.aspex webform1.aspex

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs" Inherits="HotelG.WebForm1" EnableEventValidation="false" %>

<!DOCTYPE html>

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

        <asp:DataList ID="DataList1" runat="server" Width="615px" Height="439px" >
            <ItemTemplate>
                <table>
                    <tr>

                         <td><asp:Image ID="Img1" runat="server" ImageUrl=<%# Eval("Picture")%> Height="100" style="position: relative; top: 0px; left: 98px; width: 100" /> </td>
                        <td></td>
                         <td></td>
                         <td></td>
                        <td></td>
                         <td></td>
                         <td></td>
                        <td></td>
                         <td></td>
                         <td></td>
                        <td></td>
                         <td></td>
                         <td></td>
                          <td></td>
                         <td></td>
                         <td></td>
                        <td></td>
                         <td></td>
                         <td></td>
                        <td></td>
                         <td></td>
                         <td></td>
                        <td></td>
                         <td></td>
                         <td></td>

                        <asp:Label ID="Label1" runat="server" Text=<%# Eval("Room_Type")%>></asp:Label>
                        <td></td>
                         <td></td>
                         <td></td>
                        <td></td>
                         <td></td>
                         <td></td>
                        <td><asp:Button ID="btn1" runat="server"  Text="Rate"  OnClick="Button1_Click" /></td>
                    </tr>
                </table>
            </ItemTemplate>
        </asp:DataList>

        <br />

    </div>
    </form>
</body>
</html>

webform1 code-behind file webform1代码隐藏文件

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.Data.SqlClient;

namespace HotelG
{
    public partial class WebForm1 : System.Web.UI.Page
    {
        SqlConnection con = new SqlConnection(@"Data Source = (LocalDB)\MSSQLLocalDB; AttachDbFilename=C:\Users\user\Desktop\database\Golden_Rose.mdf;Integrated Security = True; Connect Timeout = 30");
        protected void Page_Load(object sender, EventArgs e)
        {

            con.Open();
            string sel = "select Room_Type , Picture from room_details";
            SqlCommand cmd = new SqlCommand(sel, con);

            DataTable dt = new DataTable();
            SqlDataAdapter da = new SqlDataAdapter(cmd);

            da.Fill(dt);
            DataList1.DataSource = dt;
            DataList1.DataBind();
            con.Close();

        }

        protected void Button1_Click(object sender, EventArgs e)
        {


            foreach (DataListItem li in DataList1.Items)
            {

                Image img = (Image)li.FindControl("Img1");
                Label lbl = (Label)li.FindControl("Label1");
                string labeltext = lbl.Text;
                string url = img.ImageUrl;
                Session["type"] = labeltext;
                Session["img"] = url;
                Response.Redirect("WebForm2.aspx");



            }





        }




    }
}

webform2 code-behind file webform2代码隐藏文件

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace HotelG
{
    public partial class WebForm2 : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {

            if (Session["type"] != null)
            {
                Label1.Text = Session["type"].ToString();

                Label5.Text = Session["type"].ToString();

            }
            if (Session["img"] != null)
            {
                Image1.ImageUrl = Session["img"].ToString();

               Label4.Text = Session["img"].ToString();

            }



        }
    }
}

Answer 1

You are redirecting in a foreach , you know that Response.Redirect redirects a client to a new URL immediately and throws a ThreadAbortException upon completion? 您正在foreach进行重定向，您知道Response.Redirect立即将客户端重定向到新的URL，并在完成时引发ThreadAbortException吗？

Instead you only need to use FindControl on the current item instead of all(actually only the first because the foreach is not fully enumerated), it's the button's NamingContainer : 取而代之的是，您只需要在当前项目上使用FindControl而不是全部（实际上仅是第一个，因为foreach未被完全枚举），它是按钮的NamingContainer ：

protected void Button1_Click(object sender, EventArgs e)
{
    DataListItem currentItem = (DataListItem)((Button) sender).NamingContainer;
    Image img = (Image)currentItem.FindControl("Img1");
    Label lbl = (Label)currentItem.FindControl("Label1");
    string labeltext = lbl.Text;
    string url = img.ImageUrl;
    Session["type"] = labeltext;
    Session["img"] = url;
    Response.Redirect("WebForm2.aspx");
}

As mentioned by Rahul in the comment section you should also not DataBind the DataList on every post back but only on the initial one. 正如Rahul在评论部分中提到的那样，您也不应该在每DataList发帖中都对DataList进行DataBind ，而应仅对最初的发贴。 Therefore use IsPostBack to check it: 因此，请使用IsPostBack进行检查：

protected void Page_Load(object sender, EventArgs e)
{
    if(!IsPostBack)
    {
        con.Open();
        string sel = "select Room_Type , Picture from room_details";
        SqlCommand cmd = new SqlCommand(sel, con);

        DataTable dt = new DataTable();
        SqlDataAdapter da = new SqlDataAdapter(cmd);

        da.Fill(dt);
        DataList1.DataSource = dt;
        DataList1.DataBind();
        con.Close();
    }
}

Otherwise all changes are lost and events aren't triggered. 否则，所有更改都将丢失，并且不会触发事件。 That applies only if ViewState is enabled which is default. 仅在启用ViewState （默认设置）的情况下适用。 It's also good practise to use the using -statement and a local variable for the connection instead of a field. 对连接使用using -statement和局部变量（而不是字段）也是一种好习惯。 That ensures that it gets closed even on error. 这样可以确保即使发生错误也可以将其关闭。

Answer 2

Why don't you try using DataList_ItemCommand event to Redirect to another page for the appropriate item that is clicked. 您为什么不尝试使用DataList_ItemCommand事件重定向到另一个页面，以单击相应的项目。

Here is what I propose you should try : 我建议您尝试以下方法：

Store PrimaryKey Id of every room into Command Argument property using a LinkButton instead of Button . 使用LinkButton而不是Button将每个房间的PrimaryKey Id存储到Command Argument属性中。
On the code behind, create the DataList_ItemCommand event and fetch the Command Argument of the item that is clicked like this : 在后面的代码上，创建DataList_ItemCommand事件并获取被单击的项目的Command Argument，如下所示：
var id = e.CommandArgument;
Use Response.Redirect in that same function and pass this ID as a query string parameter or in Session like you are doing now and fetch that on the Redirecting page. 在同一函数中使用Response.Redirect ，然后像现在一样在会话中将此ID作为查询字符串参数传递，并在“重定向”页面上获取该ID。

You can also take some reference for the DataList_ItemCommand event from this link : Pass Data to other Page using DataList and Querystring 您也可以从此链接获取有关DataList_ItemCommand事件的一些参考：使用DataList和Querystring将数据传递到其他页面

Hope this helps. 希望这可以帮助。

Answer 3

Put in CommandName and CommandArgument properties of Button Control. 放入按钮控件的CommandName和CommandArgument属性。 Put primary key of record in CommandArgument and instead of using button's click event. 将记录的主键放在CommandArgument中，而不使用按钮的click事件。 Use button's Command event. 使用按钮的Command事件。 In that event you will get an argument of type CommandEventArgs. 在这种情况下，您将获得CommandEventArgs类型的参数。 And in this event you can get the primary key of the record being rated by using CommandEventArgs arguments "CommandArgument" property and then you can do whatever you want with this particular record. 并且在这种情况下，您可以使用CommandEventArgs参数“ CommandArgument”属性来获取记录的主键，然后您可以对该特定记录执行任何操作。

如何在asp.net中配置数据列表的索引？

问题描述

3 个解决方案

解决方案1
2 已采纳 2015-12-02 09:55:47

解决方案2
0 2015-12-02 09:58:29

解决方案3
0 2015-12-02 10:04:12

如何在asp.net中配置数据列表的索引？

问题描述

3 个解决方案

解决方案1 2 已采纳 2015-12-02 09:55:47

解决方案2 0 2015-12-02 09:58:29

解决方案3 0 2015-12-02 10:04:12

解决方案1
2 已采纳 2015-12-02 09:55:47

解决方案2
0 2015-12-02 09:58:29

解决方案3
0 2015-12-02 10:04:12