c# DataTable 針對xml、excel、csv導入和導出

此段代碼是針對DataTable 對xml、excel、csv 對文件的導入和導出功能，記錄一下，以供以後使用。

一定要導入excel 並添加引用Microsoft.Office.Interop.Excel 11.0版本。

Default.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.Data;
using System.Xml;
using System.Xml.Xsl;
using System.IO;
using System.Data.OleDb;
using System.Data.Odbc;
using System.Text;
using Excel = Microsoft.Office.Interop.Excel;

namespace fantest
{
    public partial class _Default : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            Bind();
        }
        protected void Bind()
        {
            this.GridView1.DataSource = this.GetDataTable();
            this.GridView1.DataBind();
        }
        private DataTable GetDataTable()
        {
            DataSet ds = new DataSet();
            using (SqlConnection conn = new SqlConnection("server=.;uid=sa;pwd=123456;database=test"))
            {
                string sql = "select * from InfoTable where 1=1";
                SqlDataAdapter dap = new SqlDataAdapter(sql, conn);
                dap.Fill(ds,"InfoTable");
            }
            return ds.Tables["InfoTable"];
        }
        //TO XML
        protected void Button1_Click(object sender, EventArgs e)
        {
            DataTable dt = this.GetDataTable();
            StringBuilder sb = new StringBuilder();
            sb.Append("<" + dt.TableName + ">");
            foreach (DataRow row in dt.Rows)
            {
                sb.Append("<item>");

                for (int i = 0; i < dt.Columns.Count; i++)
                {
                    sb.Append("<" + dt.Columns[i].ColumnName + ">" + row[i].ToString() + "</" + dt.Columns[i].ColumnName + ">");
                }

                sb.Append("</item>");
            }
            sb.Append("</" + dt.TableName + ">");
            Response.ClearHeaders();
            Response.AppendHeader("Content-Disposition", "attachment; filename=ss.xml");
            Response.ContentType = "text/csv";
            Response.Write(sb.ToString());
            Response.End();
        }
        //FROM XML
        protected void Button2_Click(object sender, EventArgs e)
        {         
             string filepath = Server.MapPath("ss.xml");
             if (!File.Exists(filepath))
             {
                 Page.RegisterClientScriptBlock("msg", "<script>alert(該文件不存在！)</script>");
             }
             else
             {
                 StringReader StrStream = null;
                 XmlTextReader Xmlrdr = null;
                 try
                 {
                     XmlDocument xmldoc = new XmlDocument();
                     xmldoc.Load(filepath);
                     DataSet ds = new DataSet();
                     ds.ReadXml(new XmlTextReader(new StringReader(xmldoc.InnerXml)));
                     this.GridView2.DataSource = ds.Tables[0];
                     this.GridView2.DataBind();
                 }
                 catch (Exception ex)