所有的字段都是字符串
主字段1  主字段2  主字段3 
明细字段1 明细字段2  明细字段3  明细字段4 例如:
主记录1  xxxx  xxxx  xxxx 
    {    明细记录1  oooo oooo oooo oooo
         明细记录2  oooo oooo oooo oooo
         明细记录3  oooo oooo oooo oooo
    }
主记录2  xxxx  xxxx  xxxx 
    {    明细记录1  oooo oooo oooo oooo
         明细记录2  oooo oooo oooo oooo
         明细记录3  oooo oooo oooo oooo
 明细记录4  oooo oooo oooo oooo
    }
主记录3  xxxx  xxxx  xxxx 
    {    明细记录1  oooo oooo oooo oooo
    }主记录的数目不确定, 每个主记录的明细纪录数目也不确定,请问这种variant型的数组结构如何设计和解析?