使用runtime和KVC字典转模型

使用KVC字典转模型的时候,KVC是通过遍历字典中的所有的key去模型中查找有没有对应的属性名,而runtime则是先遍历模型当中的所有的属性名去字典中查找

NSObject+Model.h

#import <Foundation/Foundation.h>

@interface NSObject (Model)

+ (instancetype)modelWithDict:(NSDictionary *)dict;

@end

NSObject+Model.m

#import "NSObject+Model.h"
#import <objc/message.h>

@implementation NSObject (Model)
+ (instancetype)modelWithDict:(NSDictionary *)dict{
    // 1.创建对应类的对象
    id objc = [[self alloc] init];
    // runtime:遍历模型中所有成员属性,去字典中查找
    
    // 遍历模型所有成员属性
    // ivar:成员属性
    // class_copyIvarList:把成员属性列表复制一份给你
    // Ivar *:指向Ivar指针
    // Ivar *:指向一个成员变量数组
    // class:获取哪个类的成员属性列表
    // count:成员属性总数
    unsigned int count = 0;
    Ivar *ivarList = class_copyIvarList(self, &count);
    for (int i = 0 ; i < count; i++) {
        // 获取成员属性
       Ivar ivar = ivarList[i];
        
        // 获取成员名
       NSString *propertyName = [NSString stringWithUTF8String:ivar_getName(ivar)];
        ;
        // 获取key
        NSString *key = [propertyName substringFromIndex:1];
        // user value:字典
        // 获取字典的value
        id value = dict[key];
        // 给模型的属性赋值
        // value:字典的值
        // key:属性名
        
        // 成员属性类型
        NSString *propertyType = [NSString stringWithUTF8String:ivar_getTypeEncoding(ivar)];
        // user:NSDictionary
        // 二级转换
        // 值是字典,成员属性的类型不是字典,才需要转换成模型
        if ([value isKindOfClass:[NSDictionary class]] && ![propertyType containsString:@"NS"]) { // 需要字典转换成模型
            
            //获取到的value的值实际为 @"@\"User\"" 需要截取为User
            NSRange range = [propertyType rangeOfString:@"\""];
            propertyType = [propertyType substringFromIndex:range.location + range.length];
            range = [propertyType rangeOfString:@"\""];
            propertyType = [propertyType substringToIndex:range.location];
            // 获取需要转换类的类对象
           Class modelClass =  NSClassFromString(propertyType);
            if (modelClass) {
                value =  [modelClass modelWithDict:value];
            }
        }
        if (value) {
            [objc setValue:value forKey:key];
        }
    }
    return objc;
}
@end

模型StatusModel.h

#import <Foundation/Foundation.h>
#import "User.h"

@interface StatusModel : NSObject
@property (nonatomic, assign) NSInteger ID;
@property (nonatomic, strong) NSString *source;

@property (nonatomic, assign) NSInteger reposts_count;

@property (nonatomic, strong) NSArray *pic_urls;

@property (nonatomic, strong) NSString *created_at;

@property (nonatomic, assign) int attitudes_count;

@property (nonatomic, strong) NSString *idstr;

@property (nonatomic, strong) NSString *text;

@property (nonatomic, assign) int comments_count;

@property (nonatomic, strong) User *user;

@property (nonatomic, strong) NSDictionary *retweeted_status;

+ (__kindof StatusModel *)statusWithDict:(NSDictionary *)dict;
@end

StatusModel.m

#import "StatusModel.h"

@implementation StatusModel

+ (StatusModel *)statusWithDict:(NSDictionary *)dict {
    
    StatusModel *model = [[StatusModel alloc] init];
    [model setValuesForKeysWithDictionary:dict];
    return model;
}

//解决KVC字典转模型,字典里面的id键与系统的id冲突
- (void)setValue:(id)value forUndefinedKey:(NSString *)key {
    if ([key isEqualToString:@"id"]) {
        _ID = [value integerValue];
    }
}

@end

解析数据,转模型

- (void)viewDidLoad {
    [super viewDidLoad];

    NSString *filePath = [[NSBundle mainBundle] pathForResource:@"status.plist" ofType:nil];
    NSDictionary *dict = [NSDictionary dictionaryWithContentsOfFile:filePath];
    NSArray *dictArr = dict[@"statuses"];
    
    NSMutableArray *statuses = [NSMutableArray array];
    // 遍历字典数组
    for (NSDictionary *dict in dictArr) {
        StatusModel *status = [StatusModel modelWithDict:dict];
        [statuses addObject:status];
    }
    
}