使用gridview删除数据库条目

Question

我正在使用Visual Studio在c＃中创建一个asp.net web应用程序的过程。我的一个页面需要显示数据库中表格的信息，并提供删除任何条目的选项。当在这里问一个不同的问题时，我触及了这个问题，并很好地给了一篇好文章来看看如何删除数据库表条目。

我现在正在跟随上述文章，尽我所能复制作者的结果，但我收到了不同的结果，我在想如果有人能指出我出错的地方。我也尝试过各种其他的方式来做这件事，但最终总会碰到错误。我提供了文章I a的链接，用于指导，我的应用程序与文章相比如何，以及单击任何删除按钮时出现的错误的屏幕截图。也是我的代码，显然:)。提前致谢。

Link to the article I am following

namespace Coursework 
{ 
    public partial class View_remove_children : System.Web.UI.Page 
    { 
     private String strConnString = ConfigurationManager.ConnectionStrings["newregDBConnectionString"].ConnectionString; 
     protected void Page_Load(object sender, EventArgs e) 
     { 
      if (!IsPostBack) 
      { 
       BindData(); 
      } 
     } 

     public void BindData() 
     { 
      string strQuery = "select firstname, dob, childID" + 
           " from children"; 
      SqlCommand cmd = new SqlCommand(strQuery); 
      GridView1.DataSource = GetData(cmd); 
      GridView1.DataBind(); 
     } 

     public DataTable GetData(SqlCommand cmd) 
     { 
      DataTable dt = new DataTable(); 
      SqlConnection con = new SqlConnection(strConnString); 
      SqlDataAdapter sda = new SqlDataAdapter(); 
      cmd.CommandType = CommandType.Text; 
      cmd.Connection = con; 
      con.Open(); 
      sda.SelectCommand = cmd; 
      sda.Fill(dt); 
      return dt; 
     } 
     protected void OnPaging(object sender, GridViewPageEventArgs e) 
     { 
      BindData(); 
      GridView1.PageIndex = e.NewPageIndex; 
      GridView1.DataBind(); 
     } 
     protected void DeleteCustomer(object sender, EventArgs e) 
     { 
      LinkButton lnkRemove = (LinkButton)sender; 
      SqlConnection con = new SqlConnection(strConnString); 
      SqlCommand cmd = new SqlCommand(); 
      cmd.CommandType = CommandType.Text; 
      cmd.CommandText = "delete from children where " + 
      "childID=@childID;" + 
      "select firstname, dob, childID from children"; 
      cmd.Parameters.Add("@childID", SqlDbType.VarChar).Value = lnkRemove.CommandArgument; 
      GridView1.DataSource = GetData(cmd); 
      GridView1.DataBind(); 
     } 
     protected void UpdateCustomer(object sender, GridViewUpdateEventArgs e) 
     { 
      string firstname = ((Label)GridView1.Rows[e.RowIndex].FindControl("firstnameLbl")).Text; 
      string dob = ((TextBox)GridView1.Rows[e.RowIndex].FindControl("dobLbl")).Text; 
      string childID = ((TextBox)GridView1.Rows[e.RowIndex].FindControl("childIDlbl")).Text; 
      SqlConnection con = new SqlConnection(strConnString); 
      SqlCommand cmd = new SqlCommand(); 
      cmd.CommandType = CommandType.Text; 
      cmd.CommandText = "update children set childID=@childID,firstname=@firstname " + 
      "where childID=@childID;" + 
      "select firstname, dob, childID from children"; 
      cmd.Parameters.Add("@firstname", SqlDbType.VarChar).Value = firstname; 
      cmd.Parameters.Add("@dob", SqlDbType.VarChar).Value = dob; 
      cmd.Parameters.Add("@childID", SqlDbType.VarChar).Value = childID; 
      GridView1.EditIndex = -1; 
      GridView1.DataSource = GetData(cmd); 
      GridView1.DataBind(); 
     } 

     protected void GridView1_SelectedIndexChanged1(object sender, EventArgs e) 
     { 

     } 
    } 
} 

源代码：

<%@ Page Title="" Language="C#" MasterPageFile="~/Site.Master"  AutoEventWireup="true" CodeBehind="View_remove_children.aspx.cs" Inherits="Coursework.View_remove_children" %> 
<asp:Content ID="Content1" ContentPlaceHolderID="MainContent" runat="server"> 
<p> 
    <br /> 
</p> 
<p> 
    <asp:GridView ID="GridView1" runat="server" OnSelectedIndexChanged="GridView1_SelectedIndexChanged1" Width="255px"> 
     <Columns> 
      <asp:ButtonField CommandName="Delete" Text="Delete" /> 
     </Columns> 
    </asp:GridView> 
</p> 
<p> 
</p> 

Answer 1

您收到此错误消息的最可能原因是因为在您的GridView1上有一个未创建的事件。如果您复制并粘贴了代码，请转到您的GridView1并删除该事件。它应该看起来像GridView1_RowDeleting。删除，你的问题将得到解决。这应该在源代码视图中找到，而不是代码背后。