个人中心
gpt4 book ai didi

c# - 在 ASP.Net C# Webform 的 HTML 表格中显示 DataTable

转载 作者：太空宇宙 更新时间：2023-11-03 19:52:25 27 4
gpt4 key购买 nike

我引用这个网站尝试写代码-Display DataTable in HTML Table in ASP.Net C# Webform: http://www.aspsnippets.com/Articles/Display-DataTable-in-HTML-Table-in-ASPNet-using-C-and-VBNet.aspx

但是不能显示表格信息，显示空白页。我该如何修复此代码？谢谢。

1.CS.aspx

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

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
    <style type="text/css">
`body { font-family: Arial;font-size: 10pt; }`

        table {
            border: 1px solid #ccc;
            border-collapse: collapse;
        }

            table th {
                background-color: #F7F7F7;
                color: #333;
                font-weight: bold;
            }

            table th, table td {
                padding: 5px;
                border-color: #ccc;
            }
    </style>
</head>
<body>
    <form id="form1" runat="server">
        <div style="margin-left: auto; margin-right: auto; text-align: center;">

            <asp:PlaceHolder ID="placeholder" runat="server" />

        </div>
    </form>
</body>
</html>

2.CS.aspx.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.SqlClient;
using System.Data;
using System.Text;
using System.Configuration;




public partial class CS : System.Web.UI.Page
{

    protected void Page_Load(object sender, EventArgs e)
    {
        if (!this.IsPostBack)
        {
            PlaceHolder placeholder = new PlaceHolder();

            //Populating a DataTable from database.
            DataTable dt = this.GetData();

            //Building an HTML string.
            StringBuilder html = new StringBuilder();

            //Table start.
            html.Append("<table border = '1'>");

            //Building the Header row.
            html.Append("<tr>");
            foreach (DataColumn column in dt.Columns)
            {
                html.Append("<th>");
                html.Append(column.ColumnName);
                html.Append("</th>");
            }
            html.Append("</tr>");

            //Building the Data rows.
            foreach (DataRow row in dt.Rows)
            {
                html.Append("<tr>");
                foreach (DataColumn column in dt.Columns)
                {
                    html.Append("<td>");
                    html.Append(row[column.ColumnName]);
                    html.Append("</td>");
                }
                html.Append("</tr>");
            }

            //Table end.
            html.Append("</table>");
            string strText = html.ToString();

            ////Append the HTML string to Placeholder.
            placeholder.Controls.Add(new Literal { Text = html.ToString() });

        }
    }

    private DataTable GetData()
    {
        string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
        using (SqlConnection con = new SqlConnection(constr))
        {
            using (SqlCommand cmd = new SqlCommand("SELECT TOP 10 [a01],[a02],[a03] FROM [aaa].[dbo].[bbb]"))
            {
                using (SqlDataAdapter sda = new SqlDataAdapter())
                {
                    cmd.Connection = con;
                    sda.SelectCommand = cmd;
                    using (DataTable dt = new DataTable())
                    {
                        sda.Fill(dt);
                        return dt;
                    }
                }
            }
        }
    }
}

最佳答案

如果我有要点，我会发表评论，但要解决您的问题，您需要做的就是注释掉以下行:

PlaceHolder placeholder = new PlaceHolder();

原因是，你有一个 PlaceHolder名为 placeholder在你的标记上，然后创建一个全新的 placeholder PlaceHolder 类型的变量在加载代码中。虽然它们的名称相同，但代码将它们视为 2 个完全不同的对象。请参阅下面的代码，我还借用了别人的代码来创建一个 datatable ，因为我无权访问您的数据库。

protected void Page_Load(object sender, EventArgs e)
{
    if (!IsPostBack)
    {
        /*
        Commented out because doing it this way creates 
        2 PlaceHolder variables named placeholder, everything else is as needed
        */
        //PlaceHolder placeholder = new PlaceHolder();

        //Populating a DataTable from database.
        DataTable dt = this.GetData();
        //Building an HTML string.
        StringBuilder html = new StringBuilder();
        //Table start.
        html.Append("<table border = '1'>");
        //Building the Header row.
        html.Append("<tr>");
        foreach (DataColumn column in dt.Columns)
        {
            html.Append("<th>");
            html.Append(column.ColumnName);
            html.Append("</th>");
        }
        html.Append("</tr>");
        //Building the Data rows.
        foreach (DataRow row in dt.Rows)
        {
            html.Append("<tr>");
            foreach (DataColumn column in dt.Columns)
            {
                html.Append("<td>");
                html.Append(row[column.ColumnName]);
                html.Append("</td>");
            }
            html.Append("</tr>");
        }
        //Table end.
        html.Append("</table>");
        string strText = html.ToString();
        ////Append the HTML string to Placeholder.
        placeholder.Controls.Add(new Literal { Text = html.ToString() });
    }
}
private DataTable GetData()
{
    // Modified your method, since I don't have access to your db, so I created one manually
    // Here we create a DataTable with four columns.
    DataTable table = new DataTable();
    table.Columns.Add("Dosage", typeof(int));
    table.Columns.Add("Drug", typeof(string));
    table.Columns.Add("Patient", typeof(string));
    table.Columns.Add("Date", typeof(DateTime));

    // Here we add five DataRows.
    table.Rows.Add(25, "Indocin", "David", DateTime.Now);
    table.Rows.Add(50, "Enebrel", "Sam", DateTime.Now);
    table.Rows.Add(10, "Hydralazine", "Christoff", DateTime.Now);
    table.Rows.Add(21, "Combivent", "Janet", DateTime.Now);
    table.Rows.Add(100, "Dilantin", "Melanie", DateTime.Now);
    return table;
}

关于c# - 在 ASP.Net C# Webform 的 HTML 表格中显示 DataTable，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/37382144/

27 4 0
文章推荐： c# - 带有简单注入(inject)器的 ASP.NET Core
文章推荐： python - 如何禁用警告 "tensorflow:Method (on_train_batch_end) is slow compared to the batch update (). Check your callbacks"
文章推荐： python - 是否可以在 matplotlib 中的动画过程中改变速度
文章推荐： python - 将 YAML 转换为 JSON 时出错 : yaml: line 3: did not find expected key
太空宇宙
个人简介

我是一名优秀的程序员,十分优秀！

滴滴打车优惠券免费领取
滴滴打车优惠券
全站热门文章
Copyright 2021 - 2024 cfsdn All Rights Reserved 蜀ICP备2022000587号
广告合作:1813099741@qq.com 6ren.com