下午上班时间闲来无事，阅读了下autolayout开源框架masonry示例Demo，被他们优雅的代码吸引住了。

或许这才是真正的MVC。

C:Controller像这样，一个Controller控制N多个View，多么优雅。而我之前都是习惯一个View对应一个ViewController,多么low...

MASExampleListViewController.h

#import <UIKit/UIKit.h>

@interface MASExampleListViewController : UITableViewController

@end

MASExampleListViewController.m

#import "MASExampleListViewController.h"
#import "MASExampleViewController.h"
#import "MASExampleBasicView.h"
#import "MASExampleConstantsView.h"
#import "MASExampleSidesView.h"
#import "MASExampleAnimatedView.h"
#import "MASExampleDebuggingView.h"
#import "MASExampleLabelView.h"
#import "MASExampleUpdateView.h"
#import "MASExampleRemakeView.h"
#import "MASExampleScrollView.h"
#import "MASExampleLayoutGuideViewController.h"
#import "MASExampleArrayView.h"
#import "MASExampleAttributeChainingView.h"
#import "MASExampleAspectFitView.h"
#import "MASExampleMarginView.h"
#import "MASExampleDistributeView.h"

static NSString * const kMASCellReuseIdentifier = @"kMASCellReuseIdentifier";

@interface MASExampleListViewController ()

@property (nonatomic, strong) NSArray *exampleControllers;

@end

@implementation MASExampleListViewController

- (id)init {
    self = [super init];
    if (!self) return nil;
    
    self.title = @"Examples";
    
    self.exampleControllers = @[
        [[MASExampleViewController alloc] initWithTitle:@"Basic"
                                              viewClass:MASExampleBasicView.class],
        [[MASExampleViewController alloc] initWithTitle:@"Update Constraints"
                                              viewClass:MASExampleUpdateView.class],
        [[MASExampleViewController alloc] initWithTitle:@"Remake Constraints"
                                              viewClass:MASExampleRemakeView.class],
        [[MASExampleViewController alloc] initWithTitle:@"Using Constants"
                                              viewClass:MASExampleConstantsView.class],
        [[MASExampleViewController alloc] initWithTitle:@"Composite Edges"
                                              viewClass:MASExampleSidesView.class],
        [[MASExampleViewController alloc] initWithTitle:@"Aspect Fit"
                                              viewClass:MASExampleAspectFitView.class],
        [[MASExampleViewController alloc] initWithTitle:@"Basic Animated"
                                              viewClass:MASExampleAnimatedView.class],
        [[MASExampleViewController alloc] initWithTitle:@"Debugging Helpers"
                                              viewClass:MASExampleDebuggingView.class],
        [[MASExampleViewController alloc] initWithTitle:@"Bacony Labels"
                                              viewClass:MASExampleLabelView.class],
        [[MASExampleViewController alloc] initWithTitle:@"UIScrollView"
                                              viewClass:MASExampleScrollView.class],
        [[MASExampleViewController alloc] initWithTitle:@"Array"
                                              viewClass:MASExampleArrayView.class],
        [[MASExampleViewController alloc] initWithTitle:@"Attribute Chaining"
                                              viewClass:MASExampleAttributeChainingView.class],
        [[MASExampleViewController alloc] initWithTitle:@"Margins"
                                              viewClass:MASExampleMarginView.class],
        [[MASExampleViewController alloc] initWithTitle:@"Views Distribute"
                                              viewClass:MASExampleDistributeView.class],

    ];
    
    if ([UIViewController instancesRespondToSelector:@selector(topLayoutGuide)])
    {
        self.exampleControllers = [self.exampleControllers arrayByAddingObject:[[MASExampleLayoutGuideViewController alloc] init]];
    }
    
    return self;
}

- (void)viewDidLoad {
    [super viewDidLoad];

    self.view.backgroundColor = [UIColor whiteColor];
    [self.tableView registerClass:UITableViewCell.class forCellReuseIdentifier:kMASCellReuseIdentifier];
}

#pragma mark - UITableViewDataSource

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    UIViewController *viewController = self.exampleControllers[indexPath.row];
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:kMASCellReuseIdentifier forIndexPath:indexPath];
    cell.textLabel.text = viewController.title;
    return cell;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    return self.exampleControllers.count;
}

#pragma mark - UITableViewDelegate

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
    UIViewController *viewController = self.exampleControllers[indexPath.row];
    [self.navigationController pushViewController:viewController animated:YES];
}

@end

MASExampleViewController.h

#import <UIKit/UIKit.h>

@interface MASExampleViewController : UIViewController

- (id)initWithTitle:(NSString *)title viewClass:(Class)viewClass;

@end

MASExampleViewController.m

#import "MASExampleViewController.h"

@interface MASExampleViewController ()

@property (nonatomic, strong) Class viewClass;

@end

@implementation MASExampleViewController

- (id)initWithTitle:(NSString *)title viewClass:(Class)viewClass {
    self = [super init];
    if (!self) return nil;
    
    self.title = title;
    self.viewClass = viewClass;
    
    return self;
}

- (void)loadView {
    self.view = self.viewClass.new;
    self.view.backgroundColor = [UIColor whiteColor];
}

#ifdef __IPHONE_7_0
- (UIRectEdge)edgesForExtendedLayout {
    return UIRectEdgeNone;
}
#endif

@end

V： View 这里列出一个MASExampleBasicView示例下，下面还可以有N多View。而这些View共用一个MASExampleViewController。通过MASExampleViewController实例方法- (id)initWithTitle:(NSString *)title viewClass:(Class)viewClass 为MASExampleViewController赋值不同view。帅呆了。

MASExampleBasicView.m

#import "MASExampleBasicView.h"

@implementation MASExampleBasicView

- (id)init {
    self = [super init];
    if (!self) return nil;
    
    UIView *greenView = UIView.new;
    greenView.backgroundColor = UIColor.greenColor;
    greenView.layer.borderColor = UIColor.blackColor.CGColor;
    greenView.layer.borderWidth = 2;
    [self addSubview:greenView];
    
    UIView *redView = UIView.new;
    redView.backgroundColor = UIColor.redColor;
    redView.layer.borderColor = UIColor.blackColor.CGColor;
    redView.layer.borderWidth = 2;
    [self addSubview:redView];
    
    UIView *blueView = UIView.new;
    blueView.backgroundColor = UIColor.blueColor;
    blueView.layer.borderColor = UIColor.blackColor.CGColor;
    blueView.layer.borderWidth = 2;
    [self addSubview:blueView];
    
    UIView *superview = self;
    int padding = 10;

    //if you want to use Masonry without the mas_ prefix
    //define MAS_SHORTHAND before importing Masonry.h see Masonry iOS Examples-Prefix.pch
    [greenView makeConstraints:^(MASConstraintMaker *make) {
        make.top.greaterThanOrEqualTo(superview.top).offset(padding);
        make.left.equalTo(superview.left).offset(padding);
        make.bottom.equalTo(blueView.top).offset(-padding);
        make.right.equalTo(redView.left).offset(-padding);
        make.width.equalTo(redView.width);

        make.height.equalTo(redView.height);
        make.height.equalTo(blueView.height);
    }];

    //with is semantic and option
    [redView mas_makeConstraints:^(MASConstraintMaker *make) {
        make.top.equalTo(superview.mas_top).with.offset(padding); //with with
        make.left.equalTo(greenView.mas_right).offset(padding); //without with
        make.bottom.equalTo(blueView.mas_top).offset(-padding);
        make.right.equalTo(superview.mas_right).offset(-padding);
        make.width.equalTo(greenView.mas_width);
        
        make.height.equalTo(@[greenView, blueView]); //can pass array of views
    }];
    
    [blueView mas_makeConstraints:^(MASConstraintMaker *make) {
        make.top.equalTo(greenView.mas_bottom).offset(padding);
        make.left.equalTo(superview.mas_left).offset(padding);
        make.bottom.equalTo(superview.mas_bottom).offset(-padding);
        make.right.equalTo(superview.mas_right).offset(-padding);
        make.height.equalTo(@[greenView.mas_height, redView.mas_height]); //can pass array of attributes
    }];

    return self;
}
@end