免责声明：写这篇笔记纯属是方便自己以及能使用到的小伙伴们作为参考，方便查找。无任何利益关系。
本文参考使用说明地址链接： https://github.com/CoderMJLee/MJExtension （MJ大牛的解析github链接）
开发肯定离不开数据的解析，有时候后台的队友当然也是因为数据的需要才不得已搞出那么多层，各种嵌套，以至于应用开发时解析很蛋疼。我们经常用到解析数据的类库（JSON、XML）有JSONModel 、JSONKit（系统自带iOS 5 后）、MJExtension、GDataXMLNode（需要导入sqlit3）、GDataXML-HTML（直接使用）-------我知道的也是用到过的就这几个；其中关于JSON类型数据的解析效率或者说性能 MJExtension > JSONModel :
要求所有模型类必须继承自JSONModel基类；
不需要你的模型类继承任何特殊基类，毫无污染，毫无侵入性；
MJExtension是一套字典和模型之间互相转换的超轻量级框架
JSON-->Model、Core Data Model
JSONString-->Model、Core Data Model
Model、Core Data Model-->JSON
JSON Array-->Model Array、Core Data Model Array
JSONString-->Model Array、Core Data Model Array
Model Array、Core Data Model Array-->JSON Array
Coding all properties of model in one line code.
只需要一行代码，就能实现模型的所有属性进行Coding（归档和解档）
简单的字典 --> 模型
JSON字符串 --> 模型
复杂的字典 --> 模型 (模型里面包含了模型)
复杂的字典 --> 模型 (模型的数组属性里面又装着模型)
复杂的字典 --> 模型（模型属性名和字典的key不一样）
字典数组 --> 模型数组
模型 --> 字典
模型数组 --> 字典数组
字典 --> CoreData模型
归档与解档NSCoding
过滤字典的值
使用方法我就不废话了，你直接拖文件或者cocoapods导入，自己看着弄；然后记得导入头文件就行： #import "MJExtension.h"
开始放大招了：
一 、最简单的字典转换为模型
typedef enum {
SexMale,
SexFemale
} Sex;
@interface User : NSObject
@property (copy, nonatomic) NSString *name;
@property (copy, nonatomic) NSString *icon;
@property (assign, nonatomic) unsigned int age;
@property (copy, nonatomic) NSString *height;
@property (strong, nonatomic) NSNumber *money;
@property (assign, nonatomic) Sex sex;
@property (assign, nonatomic, getter=isGay) BOOL gay;
@end
/***********************************************/
NSDictionary *dict = @{
@"name" : @"Jack",
@"icon" : @"lufy.png",
@"age" : @20,
@"height" : @"1.55",
@"money" : @100.9,
@"sex" : @(SexFemale),
@"gay" : @"true"
// @"gay" : @"1"
// @"gay" : @"NO"
};
// JSON -> User
User *user = [User mj_objectWithKeyValues:dict];
NSLog(@"name=%@, icon=%@, age=%zd, height=%@, money=%@, sex=%d, gay=%d", user.name, user.icon, user.age, user.height, user.money, user.sex, user.gay);
// name=Jack, icon=lufy.png, age=20, height=1.550000, money=100.9, sex=1
二、模型中嵌套模型
@interface Status : NSObject
@property (copy, nonatomic) NSString *text;
@property (strong, nonatomic) User *user;
@property (strong, nonatomic) Status *retweetedStatus;
@end
/***********************************************/
NSDictionary *dict = @{
@"text" : @"Agree!Nice weather!",
@"user" : @{
@"name" : @"Jack",
@"icon" : @"lufy.png"
},
@"retweetedStatus" : @{
@"text" : @"Nice weather!",
@"user" : @{
@"name" : @"Rose",
@"icon" : @"nami.png"
}
}
};
// JSON -> Status
Status *status = [Status mj_objectWithKeyValues:dict];
NSString *text = status.text;
NSString *name = status.user.name;
NSString *icon = status.user.icon;
NSLog(@"text=%@, name=%@, icon=%@", text, name, icon);
// text=Agree!Nice weather!, name=Jack, icon=lufy.png
NSString *text2 = status.retweetedStatus.text;
NSString *name2 = status.retweetedStatus.user.name;
NSString *icon2 = status.retweetedStatus.user.icon;
NSLog(@"text2=%@, name2=%@, icon2=%@", text2, name2, icon2);
// text2=Nice weather!, name2=Rose, icon2=nami.png
三、模型中有个数组，数组中有模型
@interface Ad : NSObject
@property (copy, nonatomic) NSString *image;
@property (copy, nonatomic) NSString *url;
@end
@interface StatusResult : NSObject
/** Contatins status model */
@property (strong, nonatomic) NSMutableArray *statuses;
/** Contatins ad model */
@property (strong, nonatomic) NSArray *ads;
@property (strong, nonatomic) NSNumber *totalNumber;
@end
/***********************************************/
// Tell MJExtension what type model will be contained in statuses and ads.
[StatusResult mj_setupObjectClassInArray:^NSDictionary *{
return @{
@"statuses" : @"Status",
// @"statuses" : [Status class],
@"ads" : @"Ad"
// @"ads" : [Ad class]
};
}];
// Equals: StatusResult.m implements +mj_objectClassInArray method.
NSDictionary *dict = @{
@"statuses" : @[
@{
@"text" : @"Nice weather!",
@"user" : @{
@"name" : @"Rose",
@"icon" : @"nami.png"
}
},
@{
@"text" : @"Go camping tomorrow!",
@"user" : @{
@"name" : @"Jack",
@"icon" : @"lufy.png"
}
}
],
@"ads" : @[
@{
@"image" : @"ad01.png",
@"url" : @"http://www.ad01.com"
},
@{
@"image" : @"ad02.png",
@"url" : @"http://www.ad02.com"
}
],
@"totalNumber" : @"2014"
};
// JSON -> StatusResult
StatusResult *result = [StatusResult mj_objectWithKeyValues:dict];
NSLog(@"totalNumber=%@", result.totalNumber);
// totalNumber=2014
// Printing
for (Status *status in result.statuses) {
NSString *text = status.text;
NSString *name = status.user.name;
NSString *icon = status.user.icon;
NSLog(@"text=%@, name=%@, icon=%@", text, name, icon);
}
// text=Nice weather!, name=Rose, icon=nami.png
// text=Go camping tomorrow!, name=Jack, icon=lufy.png
// Printing
for (Ad *ad in result.ads) {
NSLog(@"image=%@, url=%@", ad.image, ad.url);
}
// image=ad01.png, url=http://www.ad01.com
// image=ad02.png, url=http://www.ad02.com
四、归档、解档
#import "MJExtension.h"
@implementation Bag
// NSCoding Implementation
MJExtensionCodingImplementation
@end
/***********************************************/
// what properties not to be coded
[Bag mj_setupIgnoredCodingPropertyNames:^NSArray *{
return @[@"name"];
}];
// Equals: Bag.m implements +mj_ignoredCodingPropertyNames method.
// Create model
Bag *bag = [[Bag alloc] init];
bag.name = @"Red bag";
bag.price = 200.8;
NSString *file = [NSHomeDirectory() stringByAppendingPathComponent:@"Desktop/bag.data"];
// Encoding
[NSKeyedArchiver archiveRootObject:bag toFile:file];
// Decoding
Bag *decodedBag = [NSKeyedUnarchiver unarchiveObjectWithFile:file];
NSLog(@"name=%@, price=%f", decodedBag.name, decodedBag.price);
// name=(null), price=200.800000
五、过滤字典的值
// Book
#import "MJExtension.h"
@implementation Book
- (id)mj_newValueFromOldValue:(id)oldValue property:(MJProperty *)property
{
if ([property.name isEqualToString:@"publisher"]) {
if (oldValue == nil) return @"";
} else if (property.type.typeClass == [NSDate class]) {
NSDateFormatter *fmt = [[NSDateFormatter alloc] init];
fmt.dateFormat = @"yyyy-MM-dd";
return [fmt dateFromString:oldValue];
}
return oldValue;
}
@end
// NSDictionary
NSDictionary *dict = @{
@"name" : @"5分钟突破iOS开发",
@"publishedTime" : @"2011-09-10"
};
// NSDictionary -> Book
Book *book = [Book mj_objectWithKeyValues:dict];
// printing
NSLog(@"name=%@, publisher=%@, publishedTime=%@", book.name, book.publisher, book.publishedTime);
还有好多用法我没有摘过来，想要具体的了解建议去MJ的github直接参考。MJExtension解析使用详解；
