我的IOS学习之路（一）：使用代码创建UI界面

　　此实例为使用代码动态的删除和添加标签（Label)

　　主要列举视图控制器文件，详见代码

 1 #import "FCViewController.h"
 2
 3 @interface FCViewController ()
 4 @property (strong, nonatomic) NSMutableArray *Labels;
 5 @end
 6
 7 @implementation FCViewController
 8 int nextY = 40;
 9 - (void)viewDidLoad
10 {
11     [super viewDidLoad];
12     // Do any additional setup after loading the view, typically from a nib.
13     //设置背景色
14     self.view.backgroundColor = [UIColor greenColor];
15     //实例化数组
16     self.Labels = [NSMutableArray array];
17     //创建添加按钮并设置好参数与事件响应方法
18     UIButton *addBn = [UIButton buttonWithType: UIButtonTypeRoundedRect];
19     addBn.frame = CGRectMake(30, 500, 60, 40);
20     [addBn setTitle: @"add" forState: UIControlStateNormal];
21     [addBn addTarget: self action: @selector(add:) forControlEvents:UIControlEventTouchUpInside];
22     //创建删除按钮并设置好参数与事件响应方法
23     UIButton *removeBn = [UIButton buttonWithType: UIButtonTypeRoundedRect];
24     removeBn.frame = CGRectMake(230, 500, 60, 40);
25     [removeBn setTitle: @"remove" forState: UIControlStateNormal];
26     [removeBn addTarget: self action: @selector(remove:) forControlEvents:UIControlEventTouchUpInside];
27     //将按钮添加到view控件
28     [self.view addSubview: addBn];
29     [self.view addSubview: removeBn];
30 }
31
32 - (void)didReceiveMemoryWarning
33 {
34     [super didReceiveMemoryWarning];
35     // Dispose of any resources that can be recreated.
36 }
37 //添加label
38 -(void) add: (id) sender
39 {
40     UILabel *label = [[UILabel alloc] initWithFrame: CGRectMake(80, nextY, 200, 30)];
41     label.text = @"You are the champion!";
42     [self.Labels addObject: label];
43     [self.view addSubview: label];
44     nextY += 40;
45 }
46 //删除lable
47 -(void) remove: (id) sender
48 {
49     if ([self.Labels count] > 0) {
50         //从view中删除最后一个Label
51         [[self.Labels lastObject] removeFromSuperview];
52         [self.Labels removeLastObject];
53         nextY -= 40;
54     }
55    }
56 @end