SCNetworkReachability 回调

Question

SCNetworkReachabilityCallBack 有一个指向用户指定信息的 C 指针。该信息是否保证指向在 SCNetworkReachabilitySetCallback 的上下文参数中传递的同一个上下文对象？

Boolean SCNetworkReachabilitySetCallback (
   SCNetworkReachabilityRef target,
   SCNetworkReachabilityCallBack callout,
   SCNetworkReachabilityContext *context
);

typedef void (*SCNetworkReachabilityCallBack)    (
   SCNetworkReachabilityRef target,
   SCNetworkReachabilityFlags flags,
   void *info
);

SCNetwortReachability reference

Answer 1

它指向与特定 SCNetworkReachabilityRef 关联的上下文结构的信息字段。

typedef struct {
    CFIndex     version;
    void *      info;
    const void  *(*retain)(const void *info);
    void        (*release)(const void *info);
    CFStringRef (*copyDescription)(const void *info);
} SCNetworkReachabilityContext;