Question

我是C＃的新手。无法理解这个错误意味着什么：

我只是关注简单的例子 http://csharp-video-tutorials.blogspot.com/2012/10/calling-stored-procedure-with-output.html

这是我的.aspx文件

<!DOCTYPE html>


<table style="border: 1px solid black; font-family:Arial">
    <tr>
        <td>
            Employee Name
        </td>
        <td>
            <asp:TextBox ID="txtEmployeeName" runat="server"></asp:TextBox>
        </td>
    </tr>        
    <tr>
        <td>
            Gender
        </td>
        <td>
            <asp:DropDownList ID="ddlGender" runat="server">
                <asp:ListItem>Male</asp:ListItem>
                <asp:ListItem>Female</asp:ListItem>
            </asp:DropDownList>
        </td>
    </tr> 
    <tr>
        <td>
            Salary
        </td>
        <td>
            <asp:TextBox ID="txtSalary" runat="server"></asp:TextBox>
        </td>
    </tr>       
    <tr>
        <td colspan="2">
            <asp:Button ID="btnSubmit" runat="server" Text="Submit" 
                onclick="btnSubmit_Click" />
        </td>
    </tr>          
    <tr>
        <td colspan="2">
            <asp:Label ID="lblMessage" runat="server"></asp:Label>
        </td>
    </tr>  
</table>

这是aspx.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.Data.SqlClient;
using System.Configuration;

namespace adoDemo
{
    public partial class WebForm2 : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        { }
            protected void btnSubmit_Click(object sender, EventArgs e)
        {
            //Read the connection string from Web.Config file
            string ConnectionString = ConfigurationManager.ConnectionStrings["DBCS"].ConnectionString;
            using (SqlConnection con = new SqlConnection(ConnectionString))
            {
                //Create the SqlCommand object
                SqlCommand cmd = new SqlCommand("spAddEmployee", con);
                //Specify that the SqlCommand is a stored procedure
                cmd.CommandType = System.Data.CommandType.StoredProcedure;

                //Add the input parameters to the command object
                cmd.Parameters.AddWithValue("@Name", txtEmployeeName.Text);
                cmd.Parameters.AddWithValue("@Gender", ddlGender.SelectedValue);
                cmd.Parameters.AddWithValue("@Salary", txtSalary.Text);

                //Add the output parameter to the command object
                SqlParameter outPutParameter = new SqlParameter();
                outPutParameter.ParameterName = "@EmployeeId";
                outPutParameter.SqlDbType = System.Data.SqlDbType.Int;
                outPutParameter.Direction = System.Data.ParameterDirection.Output;
                cmd.Parameters.Add(outPutParameter);

                //Open the connection and execute the query
                con.Open();
                cmd.ExecuteNonQuery();

                //Retrieve the value of the output parameter
                string EmployeeId = outPutParameter.Value.ToString();
                lblMessage.Text = "Employee Id = " + EmployeeId;
            }
        }

    }

}

如果我在.aspx

的顶部放置此指令（我想这就是它所调用的）

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm2.aspx.cs" Inherits="adoDemo.WebForm2" %>

然后我又收到了一个错误：

System.Web.HttpException: Control 'txtEmployeeName' of type 'TextBox' must be placed inside a form tag with runat=server.

我错过了什么？

Answer 1

你的两页没有通讯。你没有告诉前端谁是后端。

代码隐藏模型中的@ Page指令包含属性引用外部文件和类。这些属性将.aspx页面链接到其代码。 https://msdn.microsoft.com/en-us/library/015103yb.aspx

添加了attributres后，您需要使用<form></form>属性runat="server"来标记您的标记。

User George Stocker对runat="server"属性进行了解释。

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="WebForm2.aspx.cs" Inherits="WebForm2" %>

<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
        <table style="border: 1px solid black; font-family:Arial">
            <tr>
                <td>
                    Employee Name
                </td>
                <td>
                    <asp:TextBox ID="txtEmployeeName" runat="server"></asp:TextBox>
                </td>
            </tr>        
            <tr>
                <td>
                    Gender
                </td>
                <td>
                <asp:DropDownList ID="ddlGender" runat="server">
                    <asp:ListItem>Male</asp:ListItem>
                    <asp:ListItem>Female</asp:ListItem>
                </asp:DropDownList>
                </td>
            </tr> 
            <tr>
                <td>
                    Salary
                </td>
                <td>
                    <asp:TextBox ID="txtSalary" runat="server"></asp:TextBox>
                </td>
            </tr>       
            <tr>
                <td colspan="2">
                    <asp:Button ID="btnSubmit" runat="server" Text="Submit" onclick="btnSubmit_Click" />
                </td>
            </tr>          
            <tr>
                <td colspan="2">
                    <asp:Label ID="lblMessage" runat="server"></asp:Label>
                </td>
            </tr>  
        </table>
    </form>
</body>
</html>

BC30456：＆＃39; btnSubmit_Click＆＃39;不是＆＃39; webform2_aspx＆＃39;的成员。

1 个答案: