AFNetworking 2.0 当Deployment Target低于6.0时，AFURLConnectionOperation.h,AFURLSessionManager.h

@property(nonatomic, strong) dispatch_queue_t completionQueue;

由于sdk低于6.0时，dispatch_queue_t  ARC没有托管，出现提示错误

 Property with ‘retain (or strong)‘attribute must be ofobject type

修改为

/**

 Thedispatch queue for `completionBlock`. If `NULL` (default), the main queue isused.

 */

// modify by dai date: 2014/05/22

#if OS_OBJECT_USE_OBJC

@property (nonatomic,strong)dispatch_queue_t completionQueue;

#else

@property (nonatomic,assign) dispatch_queue_tcompletionQueue;

#endif

/**

 Thedispatch group for `completionBlock`. If `NULL` (default), a private dispatchgroup is used.

 */

#if OS_OBJECT_USE_OBJC

@property (nonatomic,strong) dispatch_group_tcompletionGroup;

#else

@property (nonatomic,assign) dispatch_group_tcompletionGroup;

#endif