扒虫篇 - 定位授权前地图定位造成的黑屏

 [CLLocationManager locationServicesEnabled]
 //检测的是整个iOS系统的位置服务开关，
 //无法检测当前应用是否被关闭，只能通过CLLocationManagerDelegate的locationManager:didFailWithError:方法去检测：
在代理方法中查看权限是否改变
  - (void)locationManager:(CLLocationManager *)manager didChangeAuthorizationStatus:(CLAuthorizationStatus)status
{
 switch (status) { 
 case kCLAuthorizationStatusAuthorizedAlways: NSLog(@"Always Authorized"); break;
 case kCLAuthorizationStatusAuthorizedWhenInUse: NSLog(@"AuthorizedWhenInUse"); break; 
 case kCLAuthorizationStatusDenied: NSLog(@"Denied"); break; 
 case kCLAuthorizationStatusNotDetermined: NSLog(@"not Determined"); break;
 case kCLAuthorizationStatusRestricted: NSLog(@"Restricted"); break; default: break;
}}

 /**
    第一次执行以下语句时会有系统定位权限弹框弹出
  */
 CLLocationManager *manager = [[CLLocationManager alloc] init];      
  [manager requestAlwaysAuthorization];//一直获取定位信息
  [manager requestWhenInUseAuthorization];//使用的时候获取定位信息