多视图控制器基础篇

一.视图控制器的声明周期

1. //视图从storyboard或者xib文件中加载
2. -(void)awakeFromNib
3. {
4.     NSLog(@"awake from nib");
5. }
6. //视图将要显示
7. -(void)viewWillAppear:(BOOL)animated
8. {
9.     NSLog(@"viewWillAppear");
10. }
11. //视图创建完成
12. - (void)viewDidLoad
13. {
14.     [super viewDidLoad];
15.     NSLog(@"viewDidLoad");
16. }
17. //视图将要隐藏
18. -(void)viewWillDisappear:(BOOL)animated
19. {
20.     NSLog(@"viewWillDisappear");
21. }
22. //视图已经隐藏
23. -(void)viewDidDisappear:(BOOL)animated
24. {
25.     NSLog(@"viewDisappear");
26. }
27. //视图已经显示
28. -(void)viewDidAppear:(BOOL)animated
29. {
30.     NSLog(@"viewDidappear");
31. }
32. //视图将要布局子视图
33. -(void)viewWillLayoutSubviews
34. {
35.     NSLog(@"will layout subviews");
36. }
37. //视图已经完成布局子视图
38. -(void)viewDidLayoutSubviews
39. {
40.     NSLog(@"view did layout subviews");
41. }
42. //视图已经销毁
43. -(void)viewDidUnload
44. {
45.     NSLog(@"viewDidUnload");
46. }

二.通过empty模板的方式实现从一个控制器中打开另外一个控制器

1.建立普通模板，将Main.storyboard删除掉，然后设置main interface 为空

2.AppDelegate.m代码段如下

1. #import "AppDelegate.h"
2. #import "ViewController.h"
3. @interface AppDelegate ()
4. @end
5. @implementation AppDelegate
6. - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
7.     // Override point for customization after application launch.
8.     //创建window
9.     self.window = [[UIWindow alloc]init];
10.     CGSize screenSize = [[UIScreen mainScreen]bounds].size;
11.     //设置window的frame
12.     self.window.frame = CGRectMake(0, 0, screenSize.width, screenSize.height);
13.     //设置根控制器
14.     ViewController *viewController = [[ViewController alloc]init];
15.     [self.window setRootViewController:viewController];
16.     //接收用户响应并显示
17.     [self.window makeKeyAndVisible];
18.     return YES;
19. }

 3.viewController.m代码段如下：

1. #import "ViewController.h"
2. #import "AppDelegate.h"
3. #import "SecondViewController.h"
4. @interface ViewController ()
5. @property(strong,nonatomic)UIButton *button;
6. @end
7. @implementation ViewController
8. - (void)viewDidLoad
9. {
10.     [super viewDidLoad];
11.     self.view.backgroundColor = [UIColor redColor];
12.     self.button = [[UIButton alloc]initWithFrame:CGRectMake(100, 100, 100, 50)];
13.     [self.button setTitle:@"second" forState:UIControlStateNormal];
14.     [self.button addTarget:self action:@selector(buttonClicked:) forControlEvents:UIControlEventTouchUpInside];
15.     [self.view addSubview:self.button];
16. }
17. //按钮的单击事件
18. -(void)buttonClicked:(UIButton *)sender
19. {
20.     NSLog(@"clicked");
21.     //方式1.通过AppDdelegate获取UIWindow
22. //    AppDelegate *delegate = [[UIApplication sharedApplication]delegate];
23. //    UIWindow *window = delegate.window;
24.     //方式2.通过UIApplication直接获取UIWindow
25.     UIWindow *window = [UIApplication sharedApplication].keyWindow;
26.     //使用window切换控制器
27.     SecondViewController *second = [[SecondViewController alloc]init];
28.     //将一个控制器设置成rootViewController控制器，就可以打开这个新的控制器
29.     [window setRootViewController:second]; 
30. }