编辑和更新.NET DataList

Question

我有一个MS SQL Server数据库，其中存储了一些订单信息，而我试图能够通过GUI更新数据库中的条目。

现在，我在用户使用正确的凭据登录后加载信息，我可以在页面上查看所有这些数据并有两个按钮，一个用于编辑，另一个用于更新更改。但是，每次按下编辑按钮进入编辑模式时，页面都会刷新，数据列表中的条目不可编辑。

问题：如何制作，以便可以编辑从我的数据列表中呈现的项目，然后通过GUI在我的数据库中更新？

标记：

<%@ Page Title="Login" Language="C#" MasterPageFile="~/Site.Master" AutoEventWireup="true" CodeBehind="Login.aspx.cs" Inherits="Lab3.Login" %>
<asp:Content runat="server" ContentPlaceHolderID="MainContent">
<table>
    <p>User username 'admin' and password 'admin' to view all orders</p>
    <tr>
        <td>
        username
    </td>
    <td>
        <asp:TextBox ID="userText" runat="server"></asp:TextBox>


      </td>
    </tr>

    <tr>
        <td>
            password
        </td>
        <td>
            <asp:TextBox ID="passwordText" runat="server" TextMode="Password"></asp:TextBox>
        </td>
    </tr>
    <tr>
        <td>
            <asp:Button ID="submitButton" runat="server" Text ="Login" OnClick="submitClick"/>
        </td>
    </tr>
 </table>
  <asp:DataList id="DataList1" runat="server" EnableViewState="true" OnEditCommand="DataList1_EditCommand" OnUpdateCommand="DataList1_UpdateCommand">
            <ItemTemplate>
                <b>First Name:</b> 
                <asp:Label id="FirstName" runat="server" Text='<%# DataBinder.Eval(Container.DataItem, "FirstName") %>'></asp:Label><br />

                <b>Last Name:</b> 
                <asp:Label id="LastName" runat="server" Text='<%# DataBinder.Eval(Container.DataItem, "LastName") %>'></asp:Label><br />


                <b>Food Item:</b>
                <asp:Label id="FoodItem" runat="server" Text='<%# DataBinder.Eval(Container.DataItem, "FoodItem") %>'></asp:Label><br />

                <b>Address:</b>
                <asp:Label id="Address" runat="server" Text='<%# DataBinder.Eval(Container.DataItem, "Address") %>'></asp:Label><br />

                <b>Phone Number:</b>
                <asp:Label id="PhoneNumber" runat="server" Text='<%# DataBinder.Eval(Container.DataItem, "PhoneNumber") %>'></asp:Label><br />

                <asp:Button ID="Edit" runat="server" CommandName="Edit" Text="Edit"/>
                <asp:Button ID="Update" runat="server" CommandName="Update" Text="Update"/>

            </ItemTemplate>

            <HeaderTemplate>
                <asp:Label id="lblHeader" runat="server" Font-Names="Tahoma" ><h1>List of orders:</h1></asp:Label>
                <hr />
            </HeaderTemplate>
            <FooterTemplate>
                <hr />
            </FooterTemplate>
            <SeparatorTemplate>
                <hr />
            </SeparatorTemplate>
        </asp:DataList> 
    </asp:Content>

代码背后：

using System;
using System.Collections.Generic;
using System.Data;
using System.Data.SqlClient;
using System.Linq;
using System.Web;
using System.Web.Providers.Entities;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace Lab3
{

    public partial class Login : Page
    {
        string connect = "Data Source=(LocalDB)\\MSSQLLocalDB;AttachDbFilename=|DataDirectory|food-truck.mdf;Integrated Security=True";
        SqlCommand getAllcomand = new SqlCommand();
        DataSet ds;

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

        protected void submitClick(object sender, EventArgs e)
        {
            SqlConnection foodDB = new SqlConnection(connect);
            string Username = userText.Text;
            string Password = passwordText.Text;

            SqlCommand compare = new SqlCommand();
            compare.Connection = foodDB;
            compare.CommandText = "select * from Users where Username='" + Username + "' and Password='" + Password + "'";
            foodDB.Open();

            SqlDataAdapter da = new SqlDataAdapter(compare);
            ds = new DataSet();
            da.Fill(ds);

            bool loginSuccessful = ((ds.Tables.Count > 0) && (ds.Tables[0].Rows.Count > 0));

            if (loginSuccessful)
            { 
                Console.WriteLine("Success!");
                bind();

            }
            else
            {
                Response.Write("Authentication failed!");
                Console.WriteLine("Invalid username or password");
            }
        }

        protected void bind()
        {
            string getAllQuery = "SELECT * from dbo.OrderTable";
            using (SqlConnection con = new SqlConnection(connect))
            {
                string[] checkarray = new string[100];

                SqlCommand command = new SqlCommand(getAllQuery, con);
                con.Open();
                SqlDataReader reader = command.ExecuteReader();
                DataList1.DataSource = reader;
                DataList1.DataBind();
            }
        }

        protected void DataList1_EditCommand(object source, DataListCommandEventArgs e)
        {
            DataList1.EditItemIndex = e.Item.ItemIndex;
            bind();
        }

        protected void DataList1_UpdateCommand(object source, DataListCommandEventArgs e)
        {
            bind();

        }

        protected void DataList1_CancelCommand(object source, DataListCommandEventArgs e)
        {

        }
    }

}

Answer 1

您应该将EditItemTemplate添加到DataList。

<asp:DataList id="DataList1" runat="server" EnableViewState="true" OnItemCommand="dtlList_ItemCommand"><ItemTemplate>
            <b>First Name:</b> 
            <asp:Label id="FirstName" runat="server" Text='<%# DataBinder.Eval(Container.DataItem, "FirstName") %>'></asp:Label><br />

            <b>Last Name:</b> 
            <asp:Label id="LastName" runat="server" Text='<%# DataBinder.Eval(Container.DataItem, "LastName") %>'></asp:Label><br />


            <b>Food Item:</b>
            <asp:Label id="FoodItem" runat="server" Text='<%# DataBinder.Eval(Container.DataItem, "FoodItem") %>'></asp:Label><br />

            <b>Address:</b>
            <asp:Label id="Address" runat="server" Text='<%# DataBinder.Eval(Container.DataItem, "Address") %>'></asp:Label><br />

            <b>Phone Number:</b>
            <asp:Label id="PhoneNumber" runat="server" Text='<%# DataBinder.Eval(Container.DataItem, "PhoneNumber") %>'></asp:Label><br />

            <asp:Button ID="Edit" runat="server" CommandName="Edit" Text="Edit"/>


        </ItemTemplate>
    <EditItemTemplate>
        <ItemTemplate>
            <b>First Name:</b> 
            <asp:TextBox id="FirstName" runat="server" Text='<%# DataBinder.Eval(Container.DataItem, "FirstName") %>'></asp:TextBox><br />

            <b>Last Name:</b> 
            <asp:TextBox id="LastName" runat="server" Text='<%# DataBinder.Eval(Container.DataItem, "LastName") %>'></asp:TextBox><br />


            <b>Food Item:</b>
            <asp:TextBox id="FoodItem" runat="server" Text='<%# DataBinder.Eval(Container.DataItem, "FoodItem") %>'></asp:TextBox><br />

            <b>Address:</b>
            <asp:TextBox id="Address" runat="server" Text='<%# DataBinder.Eval(Container.DataItem, "Address") %>'></asp:TextBox><br />

            <b>Phone Number:</b>
            <asp:TextBox id="PhoneNumber" runat="server" Text='<%# DataBinder.Eval(Container.DataItem, "PhoneNumber") %>'></asp:TextBox><br />


            <asp:Button ID="Update" runat="server" CommandName="Update" Text="Update"/>

        </ItemTemplate>
    </EditItemTemplate>

删除DataList1_EditCommand并更新命令。创建名为dtlList_ItemCommand

的OnItemCommand

protected void dtlList_ItemCommand(object source, DataListCommandEventArgs e)
    {
        if (e.CommandName.Equals("Edit"))
        {
            DataList1.EditItemIndex = e.Item.ItemIndex;
            bind();
        }
        else if (e.CommandName.Equals("Update"))
        {
            var dataListItem = DataList1.Items[DataList1.EditItemIndex];
            var name = ((TextBox)dataListItem.FindControl("FirstName")).Text;
            var lastName = ((TextBox)dataListItem.FindControl("FirstName")).Text;
            var footItem = ((TextBox)dataListItem.FindControl("FirstName")).Text;
            var address = ((TextBox)dataListItem.FindControl("FirstName")).Text;
            var phoneNumber = ((TextBox)dataListItem.FindControl("FirstName")).Text;

            // update operation
            // ... 
            DataList1.EditItemIndex = -1;
            bind();
        }
    }