iOS开发——网络请求数据处理

之前博客中介绍了iOS中常用的网络框架AFNetworking，其中常用的POST请求方法如下：

AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];
NSDictionary *parameters = @{@"foo": @"bar"};
[manager POST:@"http://example.com/resources.json" parameters:parameters success:^(AFHTTPRequestOperation *operation, id responseObject) {
NSLog(@"JSON: %@", responseObject);
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
NSLog(@"Error: %@", error);
}];

我们可以看到请求成功后返回给我们的是一个已经解析好的数据字典responseObject，然后我们需要做的就是处理这个数据字典。处理字典常用的方法是利用KVC字典转模型。字典转模型我这里总结两种方法：（1）自己编写代码 （2）利用第三方框架MJExtension

1.自己编写代码（只使用与简单的字典转模型）

假如字典如下：

NSDictionary *dict = @{
@"name" : @"Jack",
@"icon" : @"lufy.png",
@"age" : @20
};

建立模型User，User.h中代码如下：

@interface User : NSObject
@property (copy, nonatomic) NSString *name;
@property (copy, nonatomic) NSString *icon;
@property (assign, nonatomic) int age;
+(instancetype)accountWithDict:(NSDictionary *)dic;
@end

User.m中代码如下：

// 使用KVC 字典转模型 如此方便，省去了大量的赋值代码
+(instancetype)accountWithDict:(NSDictionary *)dic
{
User *user = [[self alloc] init];
[user setValuesForKeysWithDictionary:dic];
return user;
}

然后我们就可以直接利用User的类方法+(instancetype)accountWithDict:(NSDictionary *)dic来实现字典转模型。

2.利用第三方框架MJExtension（建议使用）

MJExtension is a fast, convenient and nonintrusive conversion between JSON and model.

MJExtension是一个转换速度快、使用简单方便的字典转模型框架

使用前先将MJExtensionExample/MJExtensionExample/MJExtension文件夹中的所有源代码拽入项目中

导入主头文件：#import "MJExtension.h"
MJExtension.h
MJConst.h
MJConst.m
MJFoundation.h
MJFoundation.m
MJIvar.h
MJIvar.m
MJType.h
MJType.m
NSObject+MJCoding.h
NSObject+MJCoding.m
NSObject+MJIvar.h
NSObject+MJIvar.m
NSObject+MJKeyValue.h
NSObject+MJKeyValue.m

（1）最简单的字典转模型

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

（2）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

（3）模型中有个数组属性，数组里面又要装着其他模型

@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

（4）模型中的属性名和字典中的key不相同(或者需要多级映射)

@interface Bag : NSObject
@property (copy, nonatomic) NSString *name;
@property (assign, nonatomic) double price;
@end

@interface Student : NSObject
@property (copy, nonatomic) NSString *ID;
@property (copy, nonatomic) NSString *desc;
@property (copy, nonatomic) NSString *nowName;
@property (copy, nonatomic) NSString *oldName;
@property (copy, nonatomic) NSString *nameChangedTime;
@property (strong, nonatomic) Bag *bag;
@end

/***********************************************/

// How to map
[Student mj_setupReplacedKeyFromPropertyName:^NSDictionary *{
return @{
@"ID" : @"id",
@"desc" : @"desciption",
@"oldName" : @"name.oldName",
@"nowName" : @"name.newName",
@"nameChangedTime" : @"name.info[1].nameChangedTime",
@"bag" : @"other.bag"
};
}];
// Equals: Student.m implements +mj_replacedKeyFromPropertyName method.

NSDictionary *dict = @{
@"id" : @"20",
@"desciption" : @"kids",
@"name" : @{
@"newName" : @"lufy",
@"oldName" : @"kitty",
@"info" : @[
@"test-data",
@{
@"nameChangedTime" : @"2013-08"
}
]
},
@"other" : @{
@"bag" : @{
@"name" : @"a red bag",
@"price" : @100.7
}
}
};

// JSON -> Student
Student *stu = [Student mj_objectWithKeyValues:dict];

// Printing
NSLog(@"ID=%@, desc=%@, oldName=%@, nowName=%@, nameChangedTime=%@",
stu.ID, stu.desc, stu.oldName, stu.nowName, stu.nameChangedTime);
// ID=20, desc=kids, oldName=kitty, nowName=lufy, nameChangedTime=2013-08
NSLog(@"bagName=%@, bagPrice=%f", stu.bag.name, stu.bag.price);
// bagName=a red bag, bagPrice=100.700000

（5）将一个字典数组转成模型数组

NSArray *dictArray = @[
@{
@"name" : @"Jack",
@"icon" : @"lufy.png"
},
@{
@"name" : @"Rose",
@"icon" : @"nami.png"
}
];

// JSON array -> User array
NSArray *userArray = [User mj_objectArrayWithKeyValuesArray:dictArray];

// Printing
for (User *user in userArray) {
NSLog(@"name=%@, icon=%@", user.name, user.icon);
}
// name=Jack, icon=lufy.png
// name=Rose, icon=nami.png

（6）将一个模型转成字典

// New model
User *user = [[User alloc] init];
user.name = @"Jack";
user.icon = @"lufy.png";

Status *status = [[Status alloc] init];
status.user = user;
status.text = @"Nice mood!";

// Status -> JSON
NSDictionary *statusDict = status.mj_keyValues;
NSLog(@"%@", statusDict);
/*
{
text = "Nice mood!";
user =     {
icon = "lufy.png";
name = Jack;
};
}
*/

// More complex situation
Student *stu = [[Student alloc] init];
stu.ID = @"123";
stu.oldName = @"rose";
stu.nowName = @"jack";
stu.desc = @"handsome";
stu.nameChangedTime = @"2018-09-08";

Bag *bag = [[Bag alloc] init];
bag.name = @"a red bag";
bag.price = 205;
stu.bag = bag;

NSDictionary *stuDict = stu.mj_keyValues;
NSLog(@"%@", stuDict);
/*
{
ID = 123;
bag =     {
name = "\U5c0f\U4e66\U5305";
price = 205;
};
desc = handsome;
nameChangedTime = "2018-09-08";
nowName = jack;
oldName = rose;
}
*/

（7）将一个模型数组转成字典数组

// New model array
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];

// Model array -> JSON array
NSArray *dictArray = [User mj_keyValuesArrayWithObjectArray:userArray];
NSLog(@"%@", dictArray);
/*
(
{
icon = "lufy.png";
name = Jack;
},
{
icon = "nami.png";
name = Rose;
}
)
*/