01-實現圖片按鈕的縮放、動畫效果（block的初步應用）

 1 #import "ViewController.h"
 2 
 3 #define kDelta 60
 4 
 5 @interface ViewController ()
 6 
 7 @end
 8 
 9 @implementation ViewController
10 
11 #pragma mark 封裝動畫效果的代碼
12 - (void)btnClickWithBlock:(void (^)())block
13 {
14     // 實現動畫（漸進變化）
15     [UIView beginAnimations:nil context:nil];
16     [UIView setAnimationDuration:1.0];
17     
18     block();
19     
20     [UIView commitAnimations];
21 }
22 
23 // CGAffineTransform transform
24 // 表示空間的形變狀態（旋轉角度、縮放比例）
25 #pragma mark 還原為原始狀態
26 - (IBAction)reset:(id)sender {
27     
28     [self btnClickWithBlock:^{
29         _btn.transform = CGAffineTransformIdentity;
30     }];
31 }
32 
33 #pragma mark 控制按鈕的左右旋轉
34 - (IBAction)rotate:(id)sender {
35     // tag可以用來區分控制項
36     [self btnClickWithBlock:^{
37         CGFloat angle = [sender tag]==10 ? 0-M_PI_4 : M_PI_4;
38         _btn.transform = CGAffineTransformRotate(_btn.transform, angle);
39     }];
40 }
41 
42 #pragma mark 控制按鈕的左右上下移動
43 - (IBAction)run:(id)sender {
44     
45     [self btnClickWithBlock:^{
46         CGRect imageFrame = _btn.frame;
47         NSInteger tag = [sender tag];
48         switch (tag) {
49             case 1:
50                 imageFrame.origin.y -= kDelta;
51                 break;
52             case 2:
53                 imageFrame.origin.x += kDelta;
54                 break;
55             case 3:
56                 imageFrame.origin.y += kDelta;
57                 break;
58             case 4:
59                 imageFrame.origin.x -= kDelta;
60                 break;
61                 
62             default:
63                 break;
64         }
65         _btn.frame = imageFrame;
66     }];
67 }
68 
69 #pragma mark 控制按鈕的縮放
70 - (IBAction)zoom:(id)sender {
71     
72     [self btnClickWithBlock:^{
73         CGFloat scale = [sender tag]==15 ? 1.2 : 0.8;
74         _btn.transform = CGAffineTransformScale(_btn.transform, scale, scale);
75     }];
76 }
77 @end

界面效果圖：