UIViewController的生命周期：

1、运行APP

2、-  (void)loadView

{

　　[super loadView];

}

3、- (void)viewDidLoad

{

　　[super viewDidLoad];

}

4、- (void)viewWillAppear:(BOOL)animated

{

　　[super viewWillAppear:animated];

}

5、 - (void)viewDidAppear:(BOOL)animated

{

　　[super viewDidAppear:animated];

}

6、 - (void)viewWillDisappear:(BOOL)animated

{

　　[super viewWillDisappear:animated];

}

7、 - (void)viewDidDisappear:(BOOL)animated

{

　　[super viewDidDisappear:animated];

}

8、- (void)didReceiveMemoryWarning

{

　　[super didReceiveMemoryWarning];

}

 1 UILabel标签:
 2 
 3 #import <UIKit/UIKit.h>
 4 
 5 @interface FirstViewController : UIViewController
 6 
 7 @property (nonatomic, strong) UILabel *label;
 8 
 9 @end
10 
11 
12 - (void)viewDidLoad
13 {
14     [super viewDidLoad];
15     _label =[[UILabel alloc] initWithFrame:CGRectMake(100, 50, 220, 40)];
16     _label.text = @"欢迎大家学习ios软件开发";
17     _label.textColor = [UIColor redColor];
18     [self.view addSubview:_label];
19     
20 }
 1 UIButton和UILable交互
 2 
 3 #import "FirstViewController.h"
 4 #import "GlobalDefine.h"
 5 #import "SecondViewController.h"
 6 
 7 @interface FirstViewController ()
 8 
 9 @end
10 
11 @implementation FirstViewController
12 
13 - (void)loadView
14 {
15     [super loadView];
16 
17 }
18 
19 - (void)viewDidLoad
20 {
21     [super viewDidLoad];
22     _label =[[UILabel alloc] initWithFrame:CGRectMake(100, 50, 220, 40)];
23     _label.text = @"欢迎大家学习ios软件开发";
24     _label.tag = 1;
25     _label.textColor = [UIColor redColor];
26     [self.view addSubview:_label];
27     
28     UIButton *button = [UIButton buttonWithType:UIButtonTypeSystem];
29     button.frame = CGRectMake(SCREENWIDTH - 90, SCREENHEIGHT - 60, 80, 40);
30     [button setTitle:@"下一页" forState:UIControlStateNormal];
31     [self.view addSubview:button];
32     
33     //跳转
34     [button addTarget:self action:@selector(next:) forControlEvents:UIControlEventTouchUpInside];
35 }
36 
37 - (void)next:(id)sender
38 {
39     SecondViewController *tempVC = [[SecondViewController alloc] init];
40     
41     [self presentViewController:tempVC animated:YES completion:nil];
42 }
43 
44 - (void)viewWillAppear:(BOOL)animated
45 {
46     [super viewWillAppear:animated];
47     if (_label.tag != 1)
48     {
49         _label.text = @"HAHAHAHA";
50     }
51     else
52         _label.tag = 0;
53     
54 }
55 
56 #import "SecondViewController.h"
57 #import "GlobalDefine.h"
58 
59 @interface SecondViewController ()
60 
61 @end
62 
63 @implementation SecondViewController
64 
65 - (void)viewDidLoad {
66     [super viewDidLoad];
67 
68     
69     UIButton *button = [UIButton buttonWithType:UIButtonTypeSystem];
70     button.frame = CGRectMake(20, 20, 50, 40);
71     [button setTitle:@"返回" forState:UIControlStateNormal];
72     
73     [button setTitleColor:[UIColor yellowColor] forState:UIControlStateNormal];
74     
75     [self.view addSubview:button];
76     
77     //跳转
78     [button addTarget:self action:@selector(next:) forControlEvents:UIControlEventTouchUpInside];
79 }
80 
81 - (void)next:(id)sender
82 {
83     
84     [self dismissViewControllerAnimated:YES completion:nil];
85 }
  1 - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
  2     
  3     self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
  4     self.window.rootViewController = [[ViewController alloc] init];
  5     self.window.backgroundColor = [UIColor grayColor];
  6     [self.window makeKeyAndVisible];
  7     
  8     return YES;
  9 }
 10 
 11 #import <UIKit/UIKit.h>
 12 
 13 @interface ViewController : UIViewController
 14 
 15 @property (nonatomic, strong) UILabel *label;
 16 @property (nonatomic, strong) UIButton *button;
 17 
 18 @end
 19 
 20 #import "ViewController.h"
 21 #import "GlobalDefine.h"
 22 #import "SecondViewController.h"
 23 
 24 @interface ViewController ()
 25 
 26 @end
 27 
 28 @implementation ViewController
 29 
 30 - (void)viewDidLoad
 31 {
 32     [super viewDidLoad];
 33     _label = [[UILabel alloc] initWithFrame:CGRectMake(SCREENWIDTH / 2 - 150, SCREENHEIGHT / 2 - 15, 300, 30)];
 34     _label.text = @"北京，你好！HELLO";
 35     _label.tag = 1;
 36     _label.textColor = [UIColor whiteColor];
 37     _label.font = [UIFont systemFontOfSize:22];
 38     _label.font = [UIFont boldSystemFontOfSize:23];
 39     _label.font = [UIFont italicSystemFontOfSize:25];
 40     _label.textAlignment = NSTextAlignmentCenter;
 41     [self.view addSubview:_label];
 42     
 43     _button = [UIButton buttonWithType:UIButtonTypeSystem];
 44     [_button setTitle:@"Next" forState:UIControlStateNormal];
 45     _button.frame = CGRectMake(SCREENWIDTH - 80, SCREENHEIGHT - 50, 60, 30);
 46     [_button setTitleColor:[UIColor yellowColor] forState:UIControlStateNormal];
 47     _button.titleLabel.font = [UIFont systemFontOfSize:20];//设置按钮字体大小
 48     [self.view addSubview:_button];
 49     
 50     //跳转
 51     [_button addTarget:self action:@selector(next:) forControlEvents:UIControlEventTouchUpInside];
 52 }
 53 
 54 - (void)next:(id)sender
 55 {
 56     SecondViewController *tempVC = [[SecondViewController alloc] init];
 57     [self presentViewController:tempVC animated:YES completion:nil];
 58 }
 59 
 60 - (void)viewWillAppear:(BOOL)animated
 61 {
 62     if (_label.tag != 1)
 63     {
 64         _label.text = @"VIP";
 65     }
 66     else
 67     {
 68         _label.tag = 0;
 69     }
 70 }
 71 
 72 - (void)didReceiveMemoryWarning {
 73     [super didReceiveMemoryWarning];
 74     // Dispose of any resources that can be recreated.
 75 }
 76 
 77 @end
 78 
 79 #import "SecondViewController.h"
 80 #import "GlobalDefine.h"
 81 
 82 @interface SecondViewController ()
 83 
 84 @end
 85 
 86 @implementation SecondViewController
 87 
 88 - (void)viewDidLoad {
 89     [super viewDidLoad];
 90     UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(SCREENWIDTH / 2 - 130, SCREENHEIGHT / 2 - 20, 260, 40)];
 91     label.font = [UIFont systemFontOfSize:21];
 92     label.text = @"IOS is so easy! most of practice";
 93     label.textColor = [UIColor greenColor];
 94     [self.view addSubview:label];
 95     
 96     UIButton *button = [UIButton buttonWithType:UIButtonTypeSystem];
 97     button.frame = CGRectMake(SCREENWIDTH - 100, SCREENHEIGHT - 50, 80, 30);
 98     [button setTitle:@"返回" forState:UIControlStateNormal];
 99     [button setTintColor:[UIColor whiteColor]];
100     button.titleLabel.font = [UIFont systemFontOfSize:16];
101     [self.view addSubview:button];
102     
103     //跳转
104     [button addTarget:self action:@selector(back:) forControlEvents:UIControlEventTouchUpInside];
105     
106 }
107 
108 - (void)back:(id)sender
109 {
110     [self dismissViewControllerAnimated:YES completion:nil];
111 }
112 
113 - (void)didReceiveMemoryWarning {
114     [super didReceiveMemoryWarning];
115     // Dispose of any resources that can be recreated.
116 }
117 
118 /*
119 #pragma mark - Navigation
120 
121 // In a storyboard-based application, you will often want to do a little preparation before navigation
122 - (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
123     // Get the new view controller using [segue destinationViewController].
124     // Pass the selected object to the new view controller.
125 }
126 */
127 
128 @end
129 
130 
131 #ifndef GlobalDefine_h
132 #define GlobalDefine_h
133 
134 #define SCREENWIDTH [UIScreen mainScreen].bounds.size.width
135 #define SCREENHEIGHT [UIScreen mainScreen].bounds.size.height
136 
137 #endif /* GlobalDefine_h */