runtime归档接档（保存模型）

- (instancetype)initWithCoder:(NSCoder *)aDecoder{
//-(instancetype)initWithCoder:(NSCoder *)aDecoder{
    
   self = [super init];
    if (self) {
        unsigned int count = 0;
        Ivar *varList = class_copyIvarList([self class], &count);
        for (int i =0; i<count; i++) {
            
            Ivar var = varList[i];
            const char *varName =   ivar_getName(var);
            NSString *varNameString = [NSString stringWithUTF8String:varName];
            id value = [aDecoder decodeObjectForKey:varNameString];
            
            [self setValue:value forKey:varNameString];
            
        }
        
        free(varList);
        
        
    }
    
    return self;
}
- (void)encodeWithCoder:(NSCoder *)aCoder;
//-(void)encoderWithCoder:(NSCoder *)aCoder
{
    
    unsigned int count = 0;
    Ivar *varList = class_copyIvarList([self class], &count);
    for (int i =0; i<count; i++) {
        
        Ivar var = varList[i];
        const char *varName =   ivar_getName(var);
        NSString *varNameString = [NSString stringWithUTF8String:varName];
        id value = [self valueForKey:varNameString];
        
        [aCoder encodeObject:value forKey:varNameString];
        
    }
    
    free(varList);
    
}

   Person *p = [[Person alloc]init];
    p.name = @"武带";
    p.age = 24;
    p.sex = 1;
    
    
    
    NSString *temp = NSTemporaryDirectory();
    NSString *fileTemp = [temp stringByAppendingString:@"person.archive"];
    [NSKeyedArchiver archiveRootObject:p toFile:fileTemp];
    

    
    id data1 =  [NSKeyedUnarchiver unarchiveObjectWithFile:fileTemp];