确定网络可用性
Determining network availability
Parse 是否有一种方法可以用来确定互联网访问是否可用？我意识到可以使用 Apple 的 Reachability，但想知道 Parse 是否有一种方法可以轻松 return 状态。
我想在 iPhone.
上尝试更新数据之前先检查 Internet 访问
The standard way of checking for connectivity in any iOS app is to use
the Reachability APIs.
One has to be careful when specifying aggressive timeouts in queries.
Ultimately, its the user who better knows the current network
conditions and if waiting a little longer might be enough for the
query to complete (as might be the case in a tunnel), in which case
having a short timeout would make it very frustrating for the user.
For that reason, I suggest setting a NSTimer prior to executing the
query, and invalidating it when the query returns. If the NSTimer
fires before being invalidated, ask the user if they want to keep
waiting for the results to come back, or show them a message
indicating that the request is taking a long time to complete. This
gives the user the chance to wait more if they know their current
network conditions are not ideal.
You may find an example of this pattern in the Anypic sample app.
Anypic 示例应用中提到的示例：
AnyPic Sample App Repository
正如您在问题中所说的那样，可达性是解决之道。
你必须使用 AFNetworking，你可以在这里找到它：
https://github.com/AFNetworking
只需下载该 zip 并将其集成到您的项目中。
Parse 是否有一种方法可以用来确定互联网访问是否可用？我意识到可以使用 Apple 的 Reachability，但想知道 Parse 是否有一种方法可以轻松 return 状态。
我想在 iPhone.
上尝试更新数据之前先检查 Internet 访问The standard way of checking for connectivity in any iOS app is to use the Reachability APIs.
One has to be careful when specifying aggressive timeouts in queries. Ultimately, its the user who better knows the current network conditions and if waiting a little longer might be enough for the query to complete (as might be the case in a tunnel), in which case having a short timeout would make it very frustrating for the user.
For that reason, I suggest setting a NSTimer prior to executing the query, and invalidating it when the query returns. If the NSTimer fires before being invalidated, ask the user if they want to keep waiting for the results to come back, or show them a message indicating that the request is taking a long time to complete. This gives the user the chance to wait more if they know their current network conditions are not ideal.
You may find an example of this pattern in the Anypic sample app.
Anypic 示例应用中提到的示例： AnyPic Sample App Repository
正如您在问题中所说的那样，可达性是解决之道。
你必须使用 AFNetworking，你可以在这里找到它： https://github.com/AFNetworking
只需下载该 zip 并将其集成到您的项目中。