dataset 导入导出xml或excel

    //由dataset导出Excel 或Xml       
    public void ExportExcelOrXml(DataSet ds, string typeid, string FileName)
    {
        HttpResponse resp;
        resp = Page.Response;
        resp.Clear();
        resp.ContentEncoding = System.Text.Encoding.GetEncoding("GB2312");
        resp.Charset = "GB2312";
        resp.AppendHeader("Content-Disposition", "attachment;filename=" + FileName);
        string colHeaders = "", ls_item = "";
        int i = 0;

        //定义表对象和行对像，同时用DataSet对其值进行初始化
        DataTable dt = ds.Tables[0];
        DataRow[] myRow = dt.Select("");
        // typeid=="1"时导出为EXCEL格式文档；typeid=="2"时导出为XML格式文档
        if (typeid == "1")
        {
            resp.ContentType = "application/vnd.ms-excel";
            //取得数据表各列标题，各标题之间以\t分割，最后一个列标题后加回车符
            for (i = 0; i < dt.Columns.Count; i++)
            {
                if (i == dt.Columns.Count - 1)
                {
                    colHeaders += dt.Columns[i].Caption.ToString().ToLower() + "\n";
                }
                else
                {
                    colHeaders += dt.Columns[i].Caption.ToString().ToLower() + "\t";
                }
            }
            //向HTTP输出流中写入取得的数据信息
            resp.Write(colHeaders);
            //逐行处理数据
            foreach (DataRow row in myRow)
            {
                //在当前行中，逐列获得数据，数据之间以\t分割，结束时加回车符\n
                for (i = 0; i < dt.Columns.Count; i++)
                {

                    if (i == dt.Columns.Count - 1)
                    {
                        ls_item += row[i].ToString() + "\n";
                    }
                    else
                    {
                        ls_item += row[i].ToString() + "\t";
                    }
                }
                //当前行数据写入HTTP输出流，并且置空ls_item以便下行数据
                resp.Write(ls_item);
                ls_item = "";
            }
        }
        else if (typeid == "2")
        {
            //从DataSet中直接导出XML数据并且写到HTTP输出流中
            resp.Write("<?xml version=\"1.0\" encoding=\"gb2312\"?>" + ds.GetXml());
        }
        //写缓冲区中的数据到HTTP头文档中
        resp.End();
    }

　//excel导出到dataset　　　

    public static DataSet GetWorksheet(string fileName, string sheetName)
    {
        DataSet dataSet = new DataSet();
        OleDbConnection oleDbConnection = null;
        try
        {
            oleDbConnection = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + fileName + ";Extended Properties=\"Excel 8.0;HDR=YES;IMEX=1;\"");
            OleDbCommand selectCommand = new OleDbCommand();
            selectCommand.Connection = oleDbConnection;
            selectCommand.CommandText = "select * from [" + sheetName + "]";
            selectCommand.CommandType = CommandType.Text;
            OleDbDataAdapter adapter = new OleDbDataAdapter(selectCommand);
            dataSet = new DataSet();
            adapter.Fill(dataSet);
        }
        catch (Exception exception)
        {
            //oleDbConnection.Close();
            throw exception;
        }
        finally
        {
            oleDbConnection.Close();
        }
        return dataSet;
    }