如何在N层或DDD中实现异步方法？ 。净

Question

必然，我必须在每一层（DAL，BL，FRONT或Presentation，Services，UnitOfWork等）中实现异步方法吗？

我该怎么办？

选项1：

//Front: 
  - public async method() { //calling await methodMiddle() }
//BL-Domain-Whatever:
  - public async methodMiddle() { //calling await methodDAL() }
//DAL-Persistence-Whatever
  - public async methodDAL()

选项2：

//Front: 
  - public async method() ASYNC { //calling methodMiddle() }
//BL-Domain-Whatever: NO ASYNC
  - public methodMiddle() { //calling methodDAL() }
//DAL-Persistence-Whatever: NO ASYNC
  - public methodDAL() 

先谢谢!!