C#导入Excel到Dataset和导出Excel到DataTable

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
using System.Data.OleDb;
using System.Windows.Forms;
using Microsoft.Office.Interop.Excel;

namespace WinExcelOperate
{
    class ExcelOperate
    {
        //加载Excel   
        public static DataSet LoadDataFromExcel(string filePath)
        {
            try
            {
                string strConn;
                strConn = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + filePath + ";Extended Properties='Excel 8.0;HDR=False;IMEX=1'";
                OleDbConnection OleConn = new OleDbConnection(strConn);
                OleConn.Open();
                String sql = "SELECT * FROM  [Sheet1$]";//可是更改Sheet名称，比如sheet2，等等   

                OleDbDataAdapter OleDaExcel = new OleDbDataAdapter(sql, OleConn);
                DataSet OleDsExcle = new DataSet();
                OleDaExcel.Fill(OleDsExcle, "Sheet1");
                OleConn.Close();
                return OleDsExcle;
            }
            catch (Exception err)
            {
                MessageBox.Show("数据绑定Excel失败!失败原因：" + err.Message, "提示信息",
                    MessageBoxButtons.OK, MessageBoxIcon.Information);
                return null;
            }
        }

        public static void DataTabletoExcel(System.Data.DataTable tmpDataTable, string strFileName)
        {
            if (tmpDataTable == null)
                return;
            int rowNum = tmpDataTable.Rows.Count;
            int columnNum = tmpDataTable.Columns.Count;
            int rowIndex = 1;
            int columnIndex = 0;

            Microsoft.Office.Interop.Excel.Application xlApp = new Microsoft.Office.Interop.Excel.ApplicationClass();
            xlApp.DefaultFilePath = "";
            xlApp.DisplayAlerts = true;
            xlApp.SheetsInNewWorkbook = 1;
            Workbook xlBook = xlApp.Workbooks.Add(true);

            //将DataTable的列名导入Excel表第一行
            foreach (DataColumn dc in tmpDataTable.Columns)
            {
                columnIndex++;
                xlApp.Cells[rowIndex, columnIndex] = dc.ColumnName;
            }

            //将DataTable中的数据导入Excel中
            for (int i = 0; i < rowNum; i++)
            {
                rowIndex++;
                columnIndex = 0;
                for (int j = 0; j < columnNum; j++)
                {
                    columnIndex++;
                    xlApp.Cells[rowIndex, columnIndex] = tmpDataTable.Rows[i][j].ToString();
                }
            }
            //xlBook.SaveCopyAs(HttpUtility.UrlDecode(strFileName, System.Text.Encoding.UTF8));
            xlBook.SaveCopyAs(strFileName);
        }
    }
}