ASP.NET 新手 - 无法从 SQL 数据库更新 DataGrid

Question

我是 ASP.NET 的新手，我正在尝试构建一个简单的 Web 应用程序，该应用程序允许用户根据他们从 ListBox 和 Dropdown 中的选择来查看（现在只是）来自 SQL 数据库的数据。这个想法是，在做出选择后单击按钮将返回基于存储过程的数据库结果，该过程将列表和下拉选择作为参数传递。我想我已经很接近了，但我似乎无法将结果返回到为此目的指定的 DataGrid 中。我正在运行的 C# 代码如下。非常感谢任何帮助！！！

using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Xml.Linq;
using System.Windows.Forms;
using System.Data.SqlClient;

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

        }

        protected void Button1_Click(object sender, EventArgs e)
        {
            string Host = ListBox1.SelectedValue;
            string Test = DropDownList1.SelectedValue;
            this.SqlDataSource3.SelectCommand = "EXEC dbo.TEST_RESULT_DETAIL '" + Host + "', " + Test;
            //MessageBox.Show(this.SqlDataSource3.SelectCommand);
            //this.GridView1.DataBind();

            String queryString = SqlDataSource3.SelectCommand;

            MessageBox.Show(queryString);

            DataSet ds = GetData(queryString);

            if (ds.Tables.Count > 0)
            {
                //MessageBox.Show("1");
                GridView1.DataSource = ds;
                //MessageBox.Show("2");
                GridView1.DataBind();
                //MessageBox.Show("3");
            }
            else
            {
                MessageBox.Show("Unable to connect to the database.");
            }

        }

        DataSet GetData(String queryString)
        {

            // Retrieve the connection string stored in the Web.config file.
            String connectionString = ConfigurationManager.ConnectionStrings["Timeline_AnalyticsConnectionString3"].ConnectionString;

            DataSet ds = new DataSet();

            try
            {
                // Connect to the database and run the query.
                SqlConnection connection = new SqlConnection(connectionString);
                SqlDataAdapter adapter = new SqlDataAdapter(queryString, connection);

                // Fill the DataSet.
                adapter.Fill(ds);
            }
            catch (Exception ex)
            {
                // The connection failed. Display an error message.
                MessageBox.Show("Unable to connect to the database.");
            }

            return ds;
        }
    }
}

插件：

我的默认.aspx：

<%@ Page Language="C#" MasterPageFile="~/TATRRT.Master" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="Timeline_Analytics_App_Test.Default" Title="Untitled Page" %>
<asp:Content ID="Content1" ContentPlaceHolderID="head" runat="server">
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" runat="server">

<asp:ScriptManager ID="ScriptManager1" runat="server" />
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<ContentTemplate>

    <%--Host List Box--%>
    <div>
        <h4 style="font-family:verdana; font-size:10pt; position:absolute;left:10px;top:140px">Please select the host you want to review</h4>
        <asp:ListBox ID="ListBox1" runat="server" DataSourceID="SqlDataSource1" style="font-family:verdana; font-size:10pt; position:absolute;left:10px;top:180px"
            DataTextField="Host" DataValueField="Host" Height="150" Width="320"></asp:ListBox>
        <asp:SqlDataSource ID="SqlDataSource1" runat="server" 
            ConnectionString="<%$ ConnectionStrings:Timeline_Analytics_App_TestConnectionString %>"
            SelectCommand="SELECT DISTINCT Host FROM Test_Summary WHERE Category IS NULL AND Responsive = 1">
        </asp:SqlDataSource>
        <br></br>
    </div>

   <%--Test Dropdown--%>
    <div>
        <h4 style="font-family:verdana; font-size:10pt; position:absolute;left:350px;top:140px">Please select the test you want to review</h4>
        <asp:DropDownList ID="DropDownList1" runat="server" DataSourceID="SqlDataSource2" style="font-family:verdana; font-size:10pt; position:absolute;left:350px;top:180px"
            DataTextField="Test_Name" DataValueField="Test_Name" Width="320">
        </asp:DropDownList>
        <asp:SqlDataSource ID="SqlDataSource2" runat="server" 
            ConnectionString="<%$ ConnectionStrings:Timeline_Analytics_App_TestConnectionString2 %>"
            SelectCommand="SELECT DISTINCT CAST(RIGHT(REVERSE(RIGHT(REVERSE(Test_Name), 8)), 2) AS INT) AS Test_Name FROM Test_Summary ORDER BY CAST(RIGHT(REVERSE(RIGHT(REVERSE(Test_Name), 8)), 2) AS INT)"> 
        </asp:SqlDataSource>

    <%--Test Result Summary--%>
    <asp:GridView ID="GridView1" runat="server" 
            style="font-family:verdana; font-size:10pt; position:absolute;left:10px;top:350px" AllowPaging="True" 
            AutoGenerateColumns="False">
            <%--DataSourceID="SqlDataSource3"--%>
    </asp:GridView>
    <asp:SqlDataSource ID="SqlDataSource3" runat="server" 
        ConnectionString="<%$ ConnectionStrings:Timeline_AnalyticsConnectionString3 %>" 
        SelectCommand="">
    </asp:SqlDataSource>
    </div>
    <asp:Button ID="Button1" runat="server" Text="Retrieve results" 
        style="font-family:verdana; font-size:10pt; position:absolute;left:680px;top:180px" 
        onclick="Button1_Click"/>

</ContentTemplate>
</asp:UpdatePanel>

</asp:Content>

Answer 1

您的问题是AutoGenerateColumns="False" 并且您没有在标记中定义Columns，因此当GridView 数据绑定时，它没有任何可绑定的对象。

最简单的解决方法是将AutoGenerateColumns 设置为True，如下所示：

AutoGenerateColumns="True"

注意：这将使您的列名与数据库字段相同，这可能是也可能不是您想要的。

要更好地控制GridView 列，请查看GridView Column Property MSDN Documentation