asp.net导入excel转为datatable

<asp:FileUpload runat="server" ID="fupFiles" Width="300px" />
excel表名<asp:TextBox ID="txtSheet" runat="server">Sheet1</asp:TextBox>

//表名为excel左下角的表名,默认为sheet1,sheet2,...

 string excelName = txtSheet.Text; 

 string excelPath=  fupFiles.PostedFile.FileName;
 string strConn;
 strConn = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + filepath + ";Extended Properties=Excel 8.0;";
 OleDbConnection conn = new OleDbConnection(strConn);
 OleDbDataAdapter oada = new OleDbDataAdapter ( "select * from [" + sheetname + "$]", strConn );
 DataTable dt = new DataTable();
 try {
       oada.Fill(dt);//获得datatable
  }
  catch( Exception ex) {      }