xcode 出现类似的 log:
Background Task 139 ("xxx"), was created over 30 seconds ago. In applications running in the background, this creates a risk of termination. Remember to call UIApplication.endBackgroundTask(_:) for your task in a timely manner to avoid this.
原因：
由于IOS sdk进行了更新，导致beginBackgroundTaskWithExpirationHandler 没有进行正确的调用，参考：
https://stackoverflow.com/questions/10319643/proper-use-of-beginbackgroundtaskwithexpirationhandler
正确调用方式参考代码：
- (void) doUpdate
{
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
[self beginBackgroundUpdateTask];
NSURLResponse * response = nil;
NSError * error = nil;
NSData * responseData = [NSURLConnection sendSynchronousRequest: request returningResponse: &response error: &error];
// Do something with the result
[self endBackgroundUpdateTask];
});
}
- (void) beginBackgroundUpdateTask
{
self.backgroundUpdateTask = [[UIApplication sharedApplication] beginBackgroundTaskWithExpirationHandler:^{
[self endBackgroundUpdateTask];
}];
}
- (void) endBackgroundUpdateTask
{
[[UIApplication sharedApplication] endBackgroundTask: self.backgroundUpdateTask];
self.backgroundUpdateTask = UIBackgroundTaskInvalid;
}
注意以上代码只是告诉你begin和end配对调用的使用方式，具体代码的细节问题，要根据你自己的工程进行调整。