iOS MVVM架构的介绍（内含Demo）

iOS MVVM模式(Model-View-ViewModel):
1. Model层是少不了的了，我们得有东西充当DTO(数据传输对象)，当然，用字典也是可以的，编程么，要灵活一些。Model层是比较薄的一层，如果学过Java的小伙伴的话，对JavaBean应该不陌生吧。
2. ViewModel层，就是View和Model层的粘合剂，他是一个放置用户输入验证逻辑，视图显示逻辑，发起网络请求和其他各种各样的代码的极好的地方。说白了，就是把原来ViewController层的业务逻辑和页面逻辑等剥离出来放到ViewModel层。
3. View层，就是ViewController层，他的任务就是从ViewModel层获取数据，然后显示。

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MVVM实现的基本条件（限本博客）：
- 1. JSONModel
- 2. ReactiveCocoa（响应式编程）
- 3. AFNetworking
- 4. AFNetworking-RACExtensions–>AFNetworking-RACExtensions
- 5. JSONModel-RACExtension–>JSONModel-RACExtensions
- 6. 此外需要在自己的mac上搭建虚拟服务器模拟网络请求
- 7. CocoaPods的安装使用

废话不多说，看部分代码（代码较多）！

Model文件夹

#TestModel.h文件
#import "XCBaseModel.h"
#import "userinfoModel.h"

@interface TestModel : XCBaseModel

@property NSString* city;
@property userinfoModel *user_info;

@end


#import 

@interface userinfoModel : JSONModel

@property NSString* user_name;
@property NSNumber* user_code;

@end

NetWork文件夹

XCAPIManager+test.m

#import "XCAPIManager+test.h"
#import "XCAPIManager+Analysis.h"
#import "TestModel.h"

@implementation XCAPIManager (test)

- (RACSignal *)test
{
    //此处使用的mac自带的模拟服务器
    return [[[[[self rac_GET:@"http://localhost/~liuxiaochun/a.json"(http://yangjunwei.com/a/1568.html) parameters:@{}] map:^id(id value) {
        return [self analysisRequest:value];
    }] flattenMap:^RACStream *(id value) {
        if([value isKindOfClass:[NSError class]]){
            return [RACSignal return:value];
        }
        return [self rac_MappingForClass:[TestModel class] array:value[@"topic_infos"]];
    }] logError] replayLazily];
}

@end

View／ViewController文件夹

ViewController.m

#import "ViewController.h"
#import "TestViewModel.h"
#import "XCTableviewCellTest.h"

@interface ViewController ()<UITableViewDelegate,UITableViewDataSource>

#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wobjc-property-synthesis"
@property (strong, nonatomic) IBOutlet TestViewModel *viewModel;
#pragma clang diagnostic pop

@property (nonatomic,strong)NSArray* models;
@property (weak, nonatomic) IBOutlet UITableView *tableview;

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];

    @weakify(self)
    [self.viewModel.testCommand execute:nil];
    [RACObserve(self.viewModel, tests) subscribeNext:^(NSArray* x) {
        @strongify(self)
        self.models = x;
        [self.tableview reloadData];
    }];
    // Do any additional setup after loading the view, typically from a nib.
}


- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

#pragma mark - delegate / datasource
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    return self.models.count;
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString* cellId = @"cell";
    XCTableviewCellTest* cell = [tableView dequeueReusableCellWithIdentifier:cellId];

    [cell bindModel:self.models[indexPath.row]];
    return cell;
}
－－－－－－－－－－－－－－－－－
XCTableviewCellTest.m

#import "XCTableviewCellTest.h"
@implementation XCTableviewCellTest
- (void)bindModel:(TestModel *)model
{
    self.data1.text = model.city;
    self.data2.text = model.user_info.user_name;
    self.data3.text = [NSString stringWithFormat:@"%@",model.user_info.user_code];
}
@end

ViewModel文件夹

#import "TestViewModel.h"
#import "XCAPIManager+test.h"

@interface TestViewModel ()

@property (nonatomic,strong,readwrite) RACCommand* testCommand;
@property (nonatomic,strong,readwrite) NSArray* tests;

@end

@implementation TestViewModel

- (instancetype)init {
    if (self = [super init]) {

    }
    return self;
}

- (RACCommand *)testCommand
{
    if (!_testCommand) {
        @weakify(self)
        _testCommand = [[RACCommand alloc]initWithSignalBlock:^RACSignal *(id input) {
            @strongify(self)
            return [self.apiManager test];
        }];

        [[_testCommand.executionSignals concat] subscribeNext:^(NSArray* x) {
            @strongify(self)
            self.tests = x;
            NSLog(@"%@",x);
        }];
//        XPViewModelShortHand(_testCommand)
    }
    return _testCommand;
}
@end

demo: –> XCMVVM