2019 面试前的准备 -- runtime

runtime 笔记

获取类的所有属性和变量 class_copyIvarList

    #import <objc/runtime.h>

    @interface UIViewController () {
        int num; // 写在这里的都是变量
    }
    @end
    
     /// property 用该关键字定义的都属于属性
    @property (nonatomic, copy) NSString *name;
    @property (nonatomic, strong) UIView *rootView;

    @implementation UIViewController
    - (void)viewDidLoad {
    
        [super viewDidLoad];

        unsigned int count = 0;
        Ivar *ivarList = class_copyIvarList(self.class, &count);

        for (int i = 0; i < count; i ++) {

            Ivar ivar = ivarList[i];
            NSString *ivarName = [NSString stringWithUTF8String:ivar_getName(ivar)];
            LLog(@"%@",ivarName);
         }
        free(ivarList);  /// 使用copy的需要释放一下
    }

输出结果：

Cls:UIViewController.m:(49) num
Cls:UIViewController.m:(49) _name
Cls:UIViewController.m:(49) _rootView

获取所有属性 class_copyPropertyList

    unsigned int count = 0;
    objc_property_t *properts = class_copyPropertyList(self.class, &count);
    for (int i = 0; i < count; i++) {

        objc_property_t property = properts[i];
        NSString *pName = [[NSString alloc] initWithCString:property_getName(property) encoding:(NSUTF8StringEncoding)];
        NSLog(@"%@",pName);
    }
    free(properts);

输出结果：

MJApp[987:250406] name
MJApp[987:250406] rootView

获取类中的所有方法 class_copyMethodList

    Method *mList = class_copyMethodList(self.class, &count);

    for (int i = 0; i < count; i++) {

        NSLog(@"%s",sel_getName(method_getName(mList[i])));
    }
    free(mList);

输出结果：

MJApp[993:251372] .cxx_destruct
MJApp[993:251372] setName:
MJApp[993:251372] name
MJApp[993:251372] viewDidLoad
MJApp[993:251372] rootView
MJApp[993:251372] setRootView:
属性自动生成set、get方法。