Runloop and Runtime Summary

• Runloop Running Loops
  • 1; is a dead loop, the main thread is turned on by default, and the child thread does not open
  • 2. Guarantee that the program does not exit
  • 3. Monitoring events, application scenarios
    • 1. Timer, clock, Nstimer,cadisplaylink
    • 2. Monitor the reception and transmission of network port data, socket development
  • All event listeners in IOS are all responsible for running loops
  • The runloop of the main thread is automatically created when the app is launched
  • Other threads need to start themselves under that thread
  • You cannot create runloop yourself
  • Runloop is not thread-safe, so you need to avoid invoking the current thread's runloop on other threads
  • Runloop is responsible for managing autorelease pools
  • Runloop is responsible for handling message events, which are input source events, timer events, and network request things

• Runtime run time
  • Is the OC object-oriented programming language runtime Environment, Java-like virtual machine
  • Runtime is the lower level of OC implementation, the OC code eventually converted to the runtime of the C-language library of Things
    • such as data structures such as classes converted to structures in runtime
    • The method is converted to a function in the C language, and the calling method is turned into the objc_msgsend () function, which is the message mechanism
    • Import Header File <objc/message.h><objc/runtime.h>
  • What the runtime can do:
    • Get member variables in a class
    • Adding member variables dynamically for a class
    • Method implementation of dynamically changing class
    • Add new methods for class dynamics
  • Runtime usage Scenarios:
    • 1 classification category, dynamically gets the property array of the class to dynamically add properties to the class
      • Category Import Objc,class_copyivar-method-propertylist-protocol, run-time method get class attribute list
      • class method written in the taxonomy, + (Nsarray *) cz_objproperties{} get an array of properties for the class
        • 1. Establishment of classification methods, class methods
        • 2;class_copypropertylist getting an array of class attributes
        • 3; Iterate through the array,
        • 4,property_getname Get array name
        • 5; to OC string nsstringwithcstring: Add to Array
        • 6;free (prolist) Note release, Retain/creat/copy
    • 2. Dictionary to model, dynamically get the attribute array of class, set the value by KVC
      • Category + (instance) cz_objectwithdict{} convert the dictionary of the outside VC into a model object
        • 1. Get the list of properties
        • 2; Traverse Dictionary enumerate ..., get key,value,
        • 3. Determine if key is in an array of attributes [Prolist Containsobject:key]
          • If so, use KVC to assign a value, SetValue Forkey:
        • 4. Dictionary to model, written in the classification method, the model only attributes, concise
          • Drag the classification into, all the objects have this method
          • The syntax of all dictionary-to-model frames takes into account the nesting of dictionaries
    • 3, to classify, increase the associated object, the development of the framework decoupling
      • Increase efficiency by using associated objects dynamically add attributes
        • 1;objc_getassociatedobject: Before invoking the run-time method, determines whether the property array is fetched and gets the direct return
        • 2. Get an array of properties at run time
        • 3;objc_setassociatedobject: Dynamically create attributes, record attribute arrays
        • The advantage is that you don't have to call the runtime method every time to improve efficiency
    • 4; Using the run-time crossover method swizzling
      • 1. Execute your own method
      • 2; Then execute the system or third-party framework method
      • 3. Black magic, dependent on the System/Framework version, once the change is not good
        • AFN crossed the system's resume,suspend,af_resume.

Runloop and Runtime summary