Block的示例学习

  1 @interface ViewController ()
  2 
  3 
  4 @property (weak, nonatomic) IBOutlet UIButton *btn;
  5 
  6 
  7 
  8 - (IBAction)reset:(id)sender;
  9 - (IBAction)run:(id)sender;
 10 - (IBAction)rotate:(id)sender;
 11 - (IBAction)scale:(id)sender;
 12 
 13 @end
 14 
 15 @implementation ViewController
 16 
 17 - (void)viewDidLoad {
 18     [super viewDidLoad];
 19     
 20 
 21 }
 22 
 23 //定义函数,参数是block类型 无返回值,无参数的block
 24 
 25 - (void)btnClickWithBlock:(void (^)())block
 26 {
 27     // 0.动画（头部-开始动画）
 28     [UIView beginAnimations:nil context:nil];
 29     // 设置动画的执行时间
 30     [UIView setAnimationDuration:1.0];
 31     
 32     //block的调用
 33     block();
 34     
 35     // 1.动画（尾部-提交动画-执行动画）
 36     [UIView commitAnimations];
 37 }
 38 
 39 
 40 
 41 - (void)didReceiveMemoryWarning {
 42     [super didReceiveMemoryWarning];
 43     // Dispose of any resources that can be recreated.
 44 }
 45 
 46 
 47 //重置
 48 - (IBAction)reset:(id)sender {
 49     
 50     [self btnClickWithBlock:^{
 51         _btn.transform = CGAffineTransformIdentity;
 52     }];
 53 }
 54 
 55 
 56 
 57 //行走
 58 - (IBAction)run:(id)sender {
 59     
 60     [self btnClickWithBlock:^{
 61         
 62         NSLog(@"self = %@",self);   //表示此控制器
 63         
 64         // 1.先取出frame
 65         CGPoint tempCenter = _btn.center;
 66         
 67         // 2.取出按钮的tag标记
 68         NSInteger tag = [sender tag];
 69         
 70         switch (tag) {
 71             case 10:
 72                 
 73                 tempCenter.y -= kDelta;
 74                 
 75                 break;
 76                 
 77             case 20:
 78                 
 79                 tempCenter.x -= kDelta;
 80                 break;
 81                 
 82             case 30:
 83                 
 84                 tempCenter.y += kDelta;
 85                 break;
 86                 
 87                 
 88             case 40:
 89                 
 90                 tempCenter.x += kDelta;
 91                 break;
 92                 
 93                 
 94             default:
 95                 break;
 96         }
 97         
 98         // 3.重新赋值按钮的frame
 99         _btn.center = tempCenter;
100         
101         
102         
103     }];
104 }
105 
106 //旋转
107 - (IBAction)rotate:(id)sender {
108     
109     [self btnClickWithBlock:^{
110         NSInteger tag = [sender tag];
111         if (10 == tag) { // 左
112             _btn.transform = CGAffineTransformRotate(_btn.transform, M_PI_4 * -1);
113         } else { // 右
114             _btn.transform = CGAffineTransformRotate(_btn.transform, M_PI_4 * 1);
115         }
116     }];
117     
118 }
119 
120 //缩放
121 - (IBAction)scale:(id)sender {
122     
123     [self btnClickWithBlock:^{
124         CGFloat scale = [sender tag] == 20 ? 1.2 : 0.8;
125         _btn.transform = CGAffineTransformScale(_btn.transform, scale, scale);
126     }];
127     
128     
129 }