读取excel

public DataTable GetData(string strpath, string strSql,string ExcelEdition)
        {

            DataTable dtgc = null;
            OleDbConnection con = null;
            try
            {
                string strCon;
                switch(ExcelEdition)
                {
                    case "2003":
                        strCon= "provider=microsoft.jet.oledb.4.0;data source=" + strpath + ";extended properties='Excel8.0;HDR=Yes;IMEX=1'";
                        break;
                    case "2007":
                        strCon = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + strpath + ";Extended Properties=\"Excel 12.0;HDR=YES;IMEX=1\"";
                        break;
                    case "2010":
                        strCon=@"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + strpath+ ";" +"Extended Properties=\"Excel 12.0 Xml;HDR=YES;IMEX=1\"";
                        break;
                    case "userdefined":
                        strCon = strconExcel;
                        break;
                        default:
                        strCon = @"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + strpath + ";" + "Extended Properties=\"Excel 12.0 Xml;HDR=YES;IMEX=1\"";
                        break;
                }
                 if (strCon=="")
                 {
                     MessageBox.Show("没有设置自定义的连接字符串");
                     return null;
                 }
                  
            

                con = new OleDbConnection(strCon);

                OleDbCommand cmd = new OleDbCommand(strSql, con);
                OleDbDataAdapter da = new OleDbDataAdapter(cmd);
                DataSet ds = new DataSet();

                da.Fill(ds);
                dtgc = ds.Tables[0];

                return dtgc;
            }
            catch (System.Exception ex)
            {
                MessageBox.Show(ex.Message);
                return null;
            }
            finally
            {
                con.Close();
            }

        }