好的,我正在查看SimpleBackgroundFetch示例项目,它在App Delegate中使用以下内容：
[[UIApplication sharedApplication] setMinimumBackgroundFetchInterval:someTimeInSeconds];
//^this code is in didFinishLaunchingWithOptions
-(void)application:(UIApplication *)application performFetchWithCompletionHandler:(void (^)(UIBackgroundFetchResult))completionHandler
{
//do something + call completionHandler depending on new data / no data / fail
}
所以,基本上我假设,我在这里调用我的应用程序服务器,以获取一些数据.
但后来我看到了NSURLSession docs,它有这样的方法
– downloadTaskWithURL:
并说它如下：
This API provides a rich set of delegate methods for supporting
authentication and gives your app the ability to perform background
downloads when your app is not running or,in iOS,while your app is
suspended.
那么这两个API之间的区别是什么？如果我想不时地从我的应用程序的服务器下载一些数据,我应该使用什么？
