IOS开发学习笔记（五）——多视图应用程序之框架分析

我们之前学习了Single View Application的创建和设置，当然我们的程序不可能只有一个界面，所以我们需要对多视图进行支持。

我们首先来看看最简单的多视图应用：Utility Application。我们新建一个工程，选择Utility类型，结果发现我们现在有2个ViewController：MainViewController和FlipsViewController。分别有.xib(xml格式的UI描述文件，类似于Android中的layout文件)、.h头文件、.m实现文件。

接下来我们通过分析源代码查看程序的执行逻辑：

1. 对于MainView，我们看到xib右下角有个"info"的这种按钮，在执行时可以切换到FlipsView，我们查看源码得到的结果是：
   

   // info按钮点击事件- (IBAction)showInfo:(id)sender{    // 获得FlipsViewController    FlipsideViewController *controller = [[FlipsideViewController alloc] initWithNibName:@"FlipsideViewController" bundle:nil];    // 设置Controller的delegate为MainView    controller.delegate = self;    // 设置切换动画    controller.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal;    // 设置呈现Controller    [self presentViewController:controller animated:YES completion:nil];}

   
   
   
   
2. 对于FlipsView，我们查看“Done”按钮的事件处理源码：
   

   // Done按钮事件处理- (IBAction)done:(id)sender{    [self.delegate flipsideViewControllerDidFinish:self];}

   
   
   

接下来我们看一个Master-Detail的例子。Master-Detail类似于PC下的多窗口应用程序，主窗口中列表显示子窗口项，点击单项进入该项详情页面。

我们新建立一个工程之后分析：Master-Detail程序同样存在一个MasterView和一个DetailView。

其中MasterView中的代码：

////  MasterViewController.m//  MasterDetailDemo////  Created by Sam Wang on 13-5-27.//  Copyright (c) 2013年 com.freesoft. All rights reserved.//#import "MasterViewController.h"#import "DetailViewController.h"@interface MasterViewController () {    NSMutableArray *_objects;}@end@implementation MasterViewController- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil{    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];    if (self) {        // 初始化标题        self.title = NSLocalizedString(@"Master", @"Master");    }    return self;}- (void)viewDidLoad{    [super viewDidLoad];// Do any additional setup after loading the view, typically from a nib.    self.navigationItem.leftBarButtonItem = self.editButtonItem;    // 初始化Add按钮样式    UIBarButtonItem *addButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:@selector(insertNewObject:)];    self.navigationItem.rightBarButtonItem = addButton;}- (void)didReceiveMemoryWarning{    [super didReceiveMemoryWarning];    // Dispose of any resources that can be recreated.}- (void)insertNewObject:(id)sender{    // 插入新条目    if (!_objects) {        _objects = [[NSMutableArray alloc] init];    }    [_objects insertObject:[NSDate date] atIndex:0];    NSIndexPath *indexPath = [NSIndexPath indexPathForRow:0 inSection:0];    [self.tableView insertRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationAutomatic];}#pragma mark - Table View- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView{    // 设置区域    return 1;}- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{    // 条目数    return _objects.count;}// Customize the appearance of table view cells.- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{    // 显示条目    static NSString *CellIdentifier = @"Cell";        UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];    if (cell == nil) {        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];        cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;    }    NSDate *object = _objects[indexPath.row];    cell.textLabel.text = [object description];    return cell;}- (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath{    // Return NO if you do not want the specified item to be editable.    return YES;}- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath{    if (editingStyle == UITableViewCellEditingStyleDelete) {        [_objects removeObjectAtIndex:indexPath.row];        [tableView deleteRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationFade];    } else if (editingStyle == UITableViewCellEditingStyleInsert) {        // Create a new instance of the appropriate class, insert it into the array, and add a new row to the table view.    }}/*// Override to support rearranging the table view.- (void)tableView:(UITableView *)tableView moveRowAtIndexPath:(NSIndexPath *)fromIndexPath toIndexPath:(NSIndexPath *)toIndexPath{}*//*// Override to support conditional rearranging of the table view.- (BOOL)tableView:(UITableView *)tableView canMoveRowAtIndexPath:(NSIndexPath *)indexPath{    // Return NO if you do not want the item to be re-orderable.    return YES;}*/- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath{    // 选择某项条目    if (!self.detailViewController) {        self.detailViewController = [[DetailViewController alloc] initWithNibName:@"DetailViewController" bundle:nil];    }    NSDate *object = _objects[indexPath.row];    self.detailViewController.detailItem = object;    [self.navigationController pushViewController:self.detailViewController animated:YES];}@end

Detail-View代码分析：

////  DetailViewController.m//  MasterDetailDemo////  Created by Sam Wang on 13-5-27.//  Copyright (c) 2013年 com.freesoft. All rights reserved.//#import "DetailViewController.h"@interface DetailViewController ()- (void)configureView;@end@implementation DetailViewController#pragma mark - Managing the detail item- (void)setDetailItem:(id)newDetailItem{    if (_detailItem != newDetailItem) {        _detailItem = newDetailItem;                // Update the view.        [self configureView];    }}- (void)configureView{    // Update the user interface for the detail item.    // 显示条目内容    if (self.detailItem) {        self.detailDescriptionLabel.text = [self.detailItem description];    }}- (void)viewDidLoad{    [super viewDidLoad];// Do any additional setup after loading the view, typically from a nib.    [self configureView];}- (void)didReceiveMemoryWarning{    [super didReceiveMemoryWarning];    // Dispose of any resources that can be recreated.}- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil{    // 显示标题    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];    if (self) {        self.title = NSLocalizedString(@"Detail", @"Detail");    }    return self;}@end

最后我们看一个Tabbed Application，这种类型的应用还是非常多的。我们以一个简单的例子来说明如果我们需要添加一个Tab页面的情况：

1. 我们添加一个controller，我们选择New->iOS->Cocoa Touch中的Object-C Class，并且命名为：ThirdViewController，创建XIB文件。
2. 我们修改AppDelegate.m代码，增加一个viewController：
   

   - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions{    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];    // Override point for customization after application launch.    UIViewController *viewController1 = [[FirstViewController alloc] initWithNibName:@"FirstViewController" bundle:nil];    UIViewController *viewController2 = [[SecondViewController alloc] initWithNibName:@"SecondViewController" bundle:nil];    // 新增ViewController    UIViewController *viewController3 = [[ThirdViewController alloc] initWithNibName:@"ThirdViewController" bundle:nil];    self.tabBarController = [[UITabBarController alloc] init];    // 将ViewController添加到tabBar中    self.tabBarController.viewControllers = @[viewController1, viewController2, viewController3];    self.window.rootViewController = self.tabBarController;    [self.window makeKeyAndVisible];    return YES;}

   
   
   
3. ok，这时如果运行发现我们的TabView已经添加成功了，接下来我们需要修改View3的切换按钮和文字：
   

   - (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil{    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];    if (self) {        // 按钮文字        self.title = NSLocalizedString(@"Third", @"Third");        // 按钮图片        self.tabBarItem.image = [UIImage imageNamed:@"third"];    }    return self;}

   
   
   
   
4. 接下来可以对每个View编写自己的页面和逻辑。