iOS运行时 归档

runtime是属于OC的底层，可以进行一些非常底层的操作（用OC无法实现的，或者说不好实现）eg
相关的头文件
// #import <objc/runtime.h>
// #import <objc/message.h>//消息发送机制，可以直接用底层函数，进行消息发送
// 相关函数
// msg_send:给对象发送消息，来自<objc/message.h>
// class_copyMethodList,遍历某个类中所有的方法，来自<objc/runtime.h>
//#pragma mark 实例变量方法是什么意思
// class_copyIvarList,遍历某个类中所有的实例变量的方法，来自<objc/runtime.h>

// 运行时必备常识：
// 1.Ivar：成员变量的意思
// 2.Method：成员方法的意思
// 3.property:属性

运行时归档，不用担心后期类增加属性，忘记添加归档

#import <Foundation/Foundation.h>

@interface Person : NSObject<NSCoding>

@property (nonatomic, strong) NSArray *picUrls;
@property (nonatomic, copy) NSString *className;
@property (nonatomic, assign) float score;

@property (nonatomic, strong) NSNumber *number;

- (void)demo;

@end

Person.m文件

#import "Person.h"
#import <objc/runtime.h>
@implementation Person
{
    int _age;
    double _height;
    NSString *_name;
}

- (void)test
{
    NSLog(@"%s", __func__);
}

- (void)demo
{
    NSLog(@"%s", __func__);

}

/*
 - (void)encodeWithCoder:(NSCoder *)encoder
 {
 [encoder encodeObject:self.picUrls forKey:@"picUrls"];
 [encoder encodeObject:@(self.score) forKey:@"score"];
 [encoder encodeObject:self.className forKey:@"className"];
 }

 - (id)initWithCoder:(NSCoder *)decoder
 {
 if (self = [super init]) {
 self.picUrls = [decoder decodeObjectForKey:@"picUrls"];
 self.score = [[decoder decodeObjectForKey:@"score"] doubleValue];
 self.className = [decoder decodeObjectForKey:@"className"];
 }
 return self;
 }
 */

-(void)encodeWithCoder:(NSCoder *)aCoder{
    unsigned int count = 0;
    //1.取出所有的属性
    objc_property_t *propertes = class_copyPropertyList([self class], &count);
    //2.遍历的属性
    for (int i=0; i<count; i++) {
        //获取当前遍历的属性的名称
        const char *propertyName = property_getName(propertes[i]);
        NSString *name = [NSString stringWithUTF8String:propertyName];
        //利用KVC取出对应属性的值
        id value = [self valueForKey:name];
        //归档到文件中
        [aCoder encodeObject:value forKey:name];

    }
}

-(id)initWithCoder:(NSCoder *)aDecoder{
    if (self = [super init]) {
        unsigned int count =0;
        //1.取出所有的属性
        objc_property_t *propertes = class_copyPropertyList([self class], &count);
        //2.遍历所有的属性
        for (int i = 0; i < count; i++) {
            //获取当前遍历到的属性名称
            const char *propertyName = property_getName(propertes[i]);
            NSString *name = [NSString stringWithUTF8String:propertyName];
            //解归档前遍历得到的属性的值
            id value = [aDecoder decodeObjectForKey:name];
//             self.className = [decoder decodeObjectForKey:@"className"];
            [self setValue:value forKey:name];
        }

    }
    return self;
}
@end

延伸一下 runtime的使用

在控制器中我们可以测试用运行时获取 Person的实例变量，属性 ，私有和公开的方法

#import "ViewController.h"
#import "Person.h"
#import <objc/runtime.h>
@interface ViewController ()
{
     unsigned int couont;
}
@end

@implementation ViewController

-(void)viewDidLoad{
    [super viewDidLoad];
    couont = 0;
}
-(void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{
    //1.获取Person中所有的方法名称
    [self test4];
}
//1.获取Person中所有的方法名称
-(void)test1{

    /**
     *  第一参数:需要获取的类
     第二个参数:获取到的个数
     */
    Method *methds =  class_copyMethodList([Person class], &couont);
    for (int i=0; i<couont; i++) {
        //1.获取遍历得到方法名
        SEL m = method_getName(methds[i]);
        //2.将方法名称转换为字符串
        NSString *methodName = NSStringFromSelector(m);
        //3.输出
        NSLog(@"%@",methodName);
    }

}
//成员变量
-(void)test2{
    Ivar *var = class_copyIvarList([Person class], &couont);
    for (int i = 0; i < couont; i++) {
        // 1.获取遍历到得成员变量名称
        const char *varName = ivar_getName(var[i]);
        // 2.将变量名称转换为字符串
        NSString *name = [NSString stringWithUTF8String:varName];
        // 3.输出
        NSLog(@"%@", name);
    }

}
//属性
-(void)test3{
    objc_property_t *propertes = class_copyPropertyList([Person class], &couont);
    for (int i = 0; i < couont; i++) {
        // 1.获取遍历到得属性名称
        const char * propertyName =  property_getName(propertes[i]);
        // 2.将属性名称转换为字符串
        NSString *name = [NSString stringWithUTF8String:propertyName];
        // 3.输出
        NSLog(@"%@", name);
    }

}
//解归档
-(void)test4{


    Person *p2 = [NSKeyedUnarchiver unarchiveObjectWithFile:@"/Users/lanouhn/Desktop/Person.plist"];
    NSLog(@"%@",p2);
}
//归档
-(void)test5{

    Person *p = [[Person alloc] init];
    p.score = 99.8;
    p.className = @"xxxx";
    p.picUrls = @[@"123", @"456"];
    [NSKeyedArchiver archiveRootObject:p toFile:@"/Users/lanouhn/Desktop/Person.plist"];


}
@end