IOS lazy loading

IOS lazy loading

LazyLoad. It is also known as delayed loading, that is, loading only when needed (low efficiency, small memory usage ). The so-called lazy loading writes the get method.

• You do not have to write all the code for creating an object in the viewDidLoad method. The code is more readable.
• The getter method of each control is responsible for instantiating each other. The code is highly independent and loosely coupled.

   

  • You must first determine whether or not it exists. The following is the sample code @ interface ViewController ()
    @ Property (nonatomic, strong) CLLocationManager * locMgr;
    @ End
    
    -(Void) viewDidLoad {
    [Super viewDidLoad];
    
    // Start locating
    [Self. locMgr startUpdatingLocation];
    }
    
    -(CLLocationManager *) locMgr {
    If (! _ LocMgr) {// determines whether it is null
    Self. locMgr = [[CLLocationManager alloc] init];
    // Set proxy
    Self. locMgr. delegate = self;
    [Self. locMgr requestAlwaysAuthorization];
    }
    Return _ locMgr;
    }