OC中第三方库MJExtension的使用

MJExtension是一套常用的"字典和模型之间互相转换"的框架，在项目中也使用过，现在记录一下。随着Swift的普及，在Swift中也有一个类似功能的框架HandyJSON 也非常好用。有空我也会介绍一下这个框架。

MJExtension 能完成的功能

<1> 字典转模型

<2>模型转字典

<3>字典数组->模型数组

<4>模型数组->字典数组

一 字典转模型

//字典转模型
- (void) dicToModel {
    //简单的字典
    NSDictionary *dict_user = @{
                                @"name" : @"Jack",
                                @"icon" : @"lufy.png",
                                @"age" : @,
                                @"height" : @"1.55",
                                @"money" : @100.9,
                                @"sex" : @(SexFemale),/* 枚举需要使用NSNumber包装 */
                                @"gay" : @YES
                                };
    User *user = [User mj_objectWithKeyValues:dict_user];
    NSLog(@"%@  %u  %@",user.name,user.sex,user.icon);

}

二 JSON字符串转模型

- (void) stringToModel {
    NSString *jsonStr = @"{\"name\":\"Jack\", \"icon\":\"lufy.png\", \"age\":20}";
    User *user = [User mj_objectWithKeyValues:jsonStr];
    NSLog(@"%@  %u  %@",user.name,user.age,user.icon);
}

三 复杂的字典转模型

@interface Status : NSObject

@property (nonatomic,copy) NSString *text;
@property (nonatomic,strong) User *user;
@property (nonatomic,strong) Status *retweetedStatus;

@end

- (void)complexDicToModel {
    NSDictionary *dict_m8m = @{
                               @"text" : @"Agree!Nice weather!",
                               @"user" : @{
                                       @"name" : @"Jack",
                                       @"icon" : @"lufy.png"
                                       },
                               @"retweetedStatus" : @{
                                       @"text" : @"Nice weather!",
                                       @"user" : @{
                                               @"name" : @"Rose",
                                               @"icon" : @"nami.png"
                                               }
                                       }
                               };

    Status *status = [Status mj_objectWithKeyValues:dict_m8m];
    NSString *text = status.text;
    NSString *name = status.user.name;
    NSString *icon = status.user.icon;
    NSLog(@"mj-----text=%@, name=%@, icon=%@", text, name, icon);
    NSString *text2 = status.retweetedStatus.text;
    NSString *name2 = status.retweetedStatus.user.name;
    NSString *icon2 = status.retweetedStatus.user.icon;
    NSLog(@"mj-----text2=%@, name2=%@, icon2=%@", text2, name2, icon2);

}

四 模型中有个数组属性，数组里面又装着其他属性

@interface Status : NSObject

@property (nonatomic,copy) NSString *text;
@property (nonatomic,strong) User *user;
@property (nonatomic,strong) Status *retweetedStatus;

@end

@interface ADModel : NSObject

@property (nonatomic,copy) NSString *image;

@property (nonatomic,copy) NSString *url;

@end

@interface resultModel : NSObject

@property (nonatomic,strong) NSMutableArray *statuses;
@property (nonatomic,strong) NSMutableArray *ads;
@property (nonatomic,strong) NSNumber *totalNumber;
@property (nonatomic,assign) long long previousCursor;
@property (nonatomic,assign) long long nextCursor;

@end

@implementation resultModel

+ (NSDictionary *)mj_objectClassInArray {
    return @{@"statuses" : @"Status", @"ads":@"ADModel"};
}

@end

- (void)complexDicContentArrToModel {
    // 1.定义一个字典
    NSDictionary *dict = @{
                           @"statuses" : @[
                                   @{
                                       @"text" : @"今天天气真不错！",

                                       @"user" : @{
                                               @"name" : @"Rose",
                                               @"icon" : @"nami.png"
                                               }
                                       },

                                   @{
                                       @"text" : @"明天去旅游了",

                                       @"user" : @{
                                               @"name" : @"Jack",
                                               @"icon" : @"lufy.png"
                                               }
                                       }

                                   ],

                           @"ads" : @[
                                   @{
                                       @"image" : @"ad01.png",
                                       @"url" : @"http://www.小码哥ad01.com"
                                       },
                                   @{
                                       @"image" : @"ad02.png",
                                       @"url" : @"http://www.小码哥ad02.com"
                                       }
                                   ],

                           @"totalNumber" : @"",
                           @"previousCursor" : @"",
                           @"nextCursor" : @""
                           };
    resultModel *model = [resultModel mj_objectWithKeyValues:dict];
    NSLog(@"resultModel %lld ",model.nextCursor,model.previousCursor);
    // 4.打印statuses数组中的模型属性
    for (Status *status in model.statuses) {
        NSString *text = status.text;
        NSString *name = status.user.name;
        NSString *icon = status.user.icon;
        MJExtensionLog(@"text=%@, name=%@, icon=%@", text, name, icon);
    }

    // 5.打印ads数组中的模型属性
    for (ADModel *ad in model.ads) {
        MJExtensionLog(@"image=%@, url=%@", ad.image, ad.url);
    }

}

五 简单的字典转模型 (key替换 比如ID和id，支持多级映射)

@interface Bag : NSObject

@property (nonatomic,copy) NSString *name;
@property (nonatomic,assign) CGFloat price;

@end

@interface Student : NSObject

@property (copy, nonatomic) NSString *ID;
@property (copy, nonatomic) NSString *otherName;
@property (copy, nonatomic) NSString *nowName;
@property (copy, nonatomic) NSString *oldName;
@property (copy, nonatomic) NSString *nameChangedTime;
@property (copy, nonatomic) NSString *desc;
@property (strong, nonatomic) Bag *bag;

@end

@implementation Student

+ (NSDictionary *)mj_replacedKeyFromPropertyName {
    return @{@"ID":@"id",@"desc":@"desciption",@"oldName":@"name.oldName",@"nowName":@"name.newName",@"nameChangedTime":@"name.info[1].nameChangedTime",@"bag":@"other.bag"};
}

@end

- (void)keyValues2object4 {
    // 1.定义一个字典
    NSDictionary *dict = @{
                           @"id" : @"",
                           @"desciption" : @"好孩子",
                           @"name" : @{
                                   @"newName" : @"lufy",
                                   @"oldName" : @"kitty",
                                   @"info" : @[
                                           @"test-data",
                                           @{@"nameChangedTime" : @"2013-08-07"}
                                           ]
                                   },
                           @"other" : @{
                                   @"bag" : @{
                                           @"name" : @"小书包",
                                           @"price" : @100.7
                                           }
                                   }
                           };

    // 2.将字典转为MJStudent模型
    Student *stu = [Student mj_objectWithKeyValues:dict];

    // 3.打印MJStudent模型的属性
    MJExtensionLog(@"ID=%@, desc=%@, oldName=%@, nowName=%@, nameChangedTime=%@", stu.ID, stu.desc,  stu.oldName, stu.nowName, stu.nameChangedTime);
    MJExtensionLog(@"bagName=%@, bagPrice=%f", stu.bag.name, stu.bag.price);
}

六 将一个字典数组转成模型数组

- (void)arrayToModel {
    NSArray *dictArray = @[
                           @{
                               @"name" : @"Jack",
                               @"icon" : @"lufy.png"
                               },
                           @{
                               @"name" : @"Rose",
                               @"icon" : @"nami.png"
                               }
                           ];
    NSArray *userArray = [User mj_objectArrayWithKeyValuesArray:dictArray];
    for (User *user in userArray) {
        NSLog(@"name=%@, icon=%@", user.name, user.icon);
    }
}

七 将一个模型转成字典

- (void)modelToDict {
    User *user = [[User alloc] init];
    user.name = @"jack";
    user.icon = @"lufy.png";

    NSDictionary *userDic = user.mj_keyValues;
    NSLog(@"%@",userDic);
}

八 将一个模型数组转成字典数组

//模型数组 转 字典数组
- (void)modelArrayToDicArray {
    User *user1 = [[User alloc] init];
    user1.name = @"Jack";
    user1.icon = @"lufy.png";
    User *user2 = [[User alloc] init];
    user2.name = @"Rose";
    user2.icon = @"nami.png";
    NSArray *userArray = @[user1, user2];

    NSArray *dictArray = [User mj_keyValuesArrayWithObjectArray:userArray];

}

九 NSCoding 示例

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

@interface LFCar : NSObject

@property (nonatomic,copy) NSString *name;
@property (nonatomic,assign) double price;

@end

#import "LFCar.h"

@implementation LFCar

MJExtensionCodingImplementation

@end

- (void)viewDidLoad {
    [super viewDidLoad];

    LFCar *car = [[LFCar alloc] init];
    car.name = @"red bag";
    car.price = 200.8;

    NSString *file = [NSTemporaryDirectory() stringByAppendingPathComponent:@"bag.data"];
    //归档
    [NSKeyedArchiver archiveRootObject:car toFile:file];
    //解档
    LFCar *decodedCar = [NSKeyedUnarchiver unarchiveObjectWithFile:file];
    NSLog(@"%@ %f",decodedCar.name,decodedCar.price);
}

这就是MJExtension 的基本用法 还有一些其他的不常用的用法 参考这里http://blog.csdn.net/jeikerxiao/article/details/51590222