c# - ASP.NET C# MySql 选择和更新表单

Question

这里我得到了一些代码，我尝试了很多方法，我只能使用选择查询将数据显示到我的表单中，但我无法更新它，它更新但它只是更新旧值而不是我更改的新值文本框

这是表格

 <%@ Page Language="C#" AutoEventWireup="true" CodeFile="Editcar.aspx.cs" MasterPageFile="MasterPage2.master" Inherits ="Editcar" %>


<asp:Content ID="formContent" ContentPlaceHolderID="ContentPlaceHolder1" runat="server">



 <br />
 <br />
 <br />

<div class="row container">

 <form id="form1" runat="server" class="col-md-10" action="update.aspx" methode="post" >


    <asp:Table ID="GridView1" class="nav-justified" runat="server" AutoGenerateColumns="false" Height="628px" Width="763px">
        <asp:TableRow>
           <asp:TableCell>
                <h4> Car name:</h4>

           </asp:TableCell>
           <asp:TableCell>
                <asp:TextBox ID="id" runat="server" name="id" Width="301px" Text='<%# Eval("id") %>' Visible="False" CssClass="form-control"></asp:TextBox>
                <asp:TextBox ID="carmake" runat="server" Font-Names="carmake" Width="301px" Text='<%#  Eval("car_make") %>' CssClass="form-control"></asp:TextBox>

           </asp:TableCell>
        </asp:TableRow>
        <asp:TableRow>
           <asp:TableCell>
                <h4> Car model:</h4>
           </asp:TableCell>
           <asp:TableCell>
                <asp:TextBox ID="carmodel" runat="server" name="carmodel" Text='<%#  Eval("car_model") %>' Width="301px" CssClass="form-control"></asp:TextBox>
           </asp:TableCell>
        </asp:TableRow>
        <asp:TableRow>
           <asp:TableCell>
                <h4> Price: </h4>
           </asp:TableCell>
           <asp:TableCell>
                <asp:TextBox ID="price"  name="price" runat="server" Width="301px"  CssClass="form-control"></asp:TextBox>
           </asp:TableCell>
        </asp:TableRow>
        <asp:TableRow>
           <asp:TableCell>
                <h4> Discounted Price If: </h4>
           </asp:TableCell>
           <asp:TableCell>
                <asp:TextBox ID="d_price" name="d_price" runat="server" Width="301px"  CssClass="form-control"/>
           </asp:TableCell></asp:TableRow><asp:TableRow>
           <asp:TableCell> <h4>Car image (Type url)</h4></asp:TableCell><asp:TableCell>
                <asp:TextBox CssClass="form-control" ID="image"  name="image" runat="server" />Just Location
            </asp:TableCell></asp:TableRow><asp:TableRow>
           <asp:TableCell><h4>Avilability</h4></asp:TableCell><asp:TableCell>
                 <asp:TextBox CssClass="form-control" ID="avail"  name="avail" runat="server" />Just Location
           </asp:TableCell></asp:TableRow><asp:TableRow>
           <asp:TableCell><h4>Quantity</h4></asp:TableCell><asp:TableCell>
                 <asp:TextBox CssClass="form-control" ID="quantity"   name="quantity" runat="server" />Just Location
           </asp:TableCell></asp:TableRow><asp:TableRow>
           <asp:TableCell>
                <h4>Long description </h4>
           </asp:TableCell><asp:TableCell>

                <asp:TextBox ID="details" name="details" runat="server" Width="295px"  CssClass="form-control" Height="81px" TextMode="MultiLine"></asp:TextBox>
           </asp:TableCell></asp:TableRow><asp:TableRow>
           <asp:TableCell>
                <h4>Year </h4>
           </asp:TableCell><asp:TableCell>
                <asp:TextBox ID="year" name="year" runat="server" Width="295px"  CssClass="form-control" ></asp:TextBox>
           </asp:TableCell></asp:TableRow><asp:TableRow>
           <asp:TableCell>
                <h4>Special Discounted(0 0r 1) </h4>
           </asp:TableCell><asp:TableCell>
                <asp:TextBox ID="special" name="special"  runat="server" Width="295px"  CssClass="form-control"  ></asp:TextBox>
           </asp:TableCell></asp:TableRow></asp:Table><asp:Button ID="button"  runat="server"  Cssclass="btn btn-primary btn-lg btn-block" Text="Update the car" />


<br />
   <br />

   </form>


</div>
</asp:Content>

这是 CS 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.Configuration;
using System.Data;
using MySql.Data.MySqlClient;

public partial class Editcar : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;

        using (MySqlConnection con = new MySqlConnection(constr))
    {
        var id = Request.QueryString["id"];
        string selectquery = "SELECT * FROM product WHERE id=" + @id;
        MySqlCommand cmd = new MySqlCommand(selectquery);
        cmd.Connection = con;
        cmd.CommandType = CommandType.Text;
        con.Open();
        cmd.ExecuteNonQuery();

        MySqlDataAdapter da = new MySqlDataAdapter(cmd);
        DataTable dt = new DataTable();
        da.Fill(dt);

        foreach (DataRow dr in dt.Rows)

        {

            id = dr["id"].ToString();
            carmake.Text = dr["car_make"].ToString();
            carmodel.Text = dr["car_model"].ToString();
            price.Text = dr["unitprice"].ToString();
            d_price.Text = dr["discountprice"].ToString();
            image.Text = dr["image"].ToString();
            quality.Text = dr["quantity"].ToString();
            avil.Text = dr["availability"].ToString();
            details.Text = dr["details"].ToString();
            year.Text = dr["year"].ToString();
            special.Text = dr["special"].ToString();



        }
    }
}
}

这是更新页面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 MySql.Data.MySqlClient;

public partial class AdminGroup_Update: System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        string constor = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
        MySqlConnection conn = new MySqlConnection(constor);
        var id = Request.QueryString["id"];
        var carmake = Request.QueryString["carmake"];
        var carmodel = Request.QueryString["carmodel"];
        var price = Request.QueryString["price"];
        var d_price = Request.QueryString["d_price"];
        var image = Request.QueryString["image"];
        var quantity = Request.QueryString["quantity"];
        var avail = Request.QueryString["avail"];
        var details = Request.QueryString["details"];
        var year = Request.QueryString["year"];
        var special = Request.QueryString["special"];

        string sql = "Update product SET car_make=@carmake ,car_model=@carmodel ,UnitPrice=@price ,Discountprice=@d_price ,image=@image ,Quantity=@quality ,availability=@avil ,details=@details ,year=@year ,special=@special  WHERE id= @id";



        var cmd = new MySqlCommand(sql, conn);


            conn.Open();
            cmd.CommandType = CommandType.Text;
            var param = new MySqlParameter[10];

            param[0] = new MySqlParameter("@carmake", MySqlDbType.VarChar, 100);
            param[1] = new MySqlParameter("@carmodel", MySqlDbType.VarChar, 100);
            param[2] = new MySqlParameter("@price", MySqlDbType.VarChar, 100);
            param[3] = new MySqlParameter("@d_price", MySqlDbType.VarChar, 100); // put zero if no discount
            param[4] = new MySqlParameter("@image", MySqlDbType.VarChar, 300);
            param[5] = new MySqlParameter("@quantity", MySqlDbType.VarChar, 300);
            param[6] = new MySqlParameter("@avail", MySqlDbType.VarChar, 2);
            param[7] = new MySqlParameter("@details", MySqlDbType.VarChar, 2000);
            param[8] = new MySqlParameter("@year", MySqlDbType.VarChar, 4);
            param[9] = new MySqlParameter("@special", MySqlDbType.VarChar, 2);
            param[10] = new MySqlParameter("@id", MySqlDbType.VarChar, 2);

            param[0].Value = carmake;
            param[1].Value = carmodel;
            param[2].Value = price;
            param[3].Value = d_price;
            param[4].Value = image;
            param[5].Value = quality;
            param[6].Value = avil;
            param[7].Value = details;
            param[8].Value = year;
            param[9].Value = special;
            param[10].Value =id;

            var ex = cmd.ExecuteNonQuery();

            if (ex == 1)
            {
                Response.Redirect("AdminList.aspx");
            }
            else
            {
                Response.Write("Error");
            }
            conn.Close();


    }

}

Answer 1

你的按钮

 <asp:Button ID="button"  runat="server"  
             Cssclass="btn btn-primary btn-lg btn-block" 
             Text="Update the car" />

需要 OnClick setting和一个event handler在您的代码隐藏 .cs 文件中来处理它。

Webforms/dot net 的工作方式与其他一些交互式网页框架不同，因为大多数控件都会发布回同一页面，而不是发布到另一个页面。因此，您不需要单独的更新页面，并且实际上无法在正常的事件处理过程中使用它。