<pre>
- (CLPlacemark*)getStartplacemark
- {
- //先创建一个semaphore
- dispatch_queue_t queue = dispatch_get_global_queue(0, 0);
- dispatch_semaphore_t semaphore = dispatch_semaphore_create(1);
__block CLPlacemark* start;[self.geoCoder geocodeAddressString:_SourceText.text completionHandler:^(NSArray *placemarks, NSError *error) {CLPlacemark *startPlaceMark = [placemarks firstObject];start = startPlaceMark;//发出已完成的信号dispatch_semaphore_signal(semaphore);}];//等待执行，不会占用资源dispatch_semaphore_wait(semaphore, DISPATCH_TIME_FOREVER);return start;- }
</pre>
