为啥我这样不行呢 望大神告知啊

1. 
   
2. #import "ViewController.h"
   
3. 
   
4. @interface ViewController ()
   
5. 
   
6. @end
   
7. 
   
8. @implementation ViewController
   
9. 
   
10. - (void)viewDidLoad {
    
11.     [super viewDidLoad];
    
12.     // Do any additional setup after loading the view, typically from a nib.
    
13. #pragma mark - 图片按钮的创建
    
14.    
    
15.     //1.创建按钮
    
16.     UIButton *btn = [UIButton buttonWithType:UIButtonTypeCustom];
    
17.     //2.设置frame
    
18.     btn.frame=CGRectMake(50, 50, 50, 50);
    
19.     //3.设置按钮图片
    
20.     [btn setBackgroundImage:[UIImage imageNamed:@"biaoqingdi"] forState:UIControlStateNormal];
    
21.     [btn setBackgroundImage:[UIImage imageNamed:@"danteng"] forState:UIControlStateHighlighted];
    
22.     //4.设置图片文字
    
23.     [btn setTitle:@"别点我" forState:UIControlStateNormal];
    
24.     [btn setTitle:@"真点了" forState:UIControlStateHighlighted];
    
25.     //5.设置按钮文字颜色
    
26.     [btn setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
    
27.     [btn setTitleColor:[UIColor whiteColor] forState:UIControlStateHighlighted];
    
28.     //6.添加到view
    
29.     [self.view addSubview:btn];
    
30. #pragma mark - 向上
    
31.     //1.创建按钮
    
32.     UIButton *shang = [UIButton buttonWithType:UIButtonTypeCustom];
    
33.     //2.设置frame
    
34.     shang.frame = CGRectMake(150, 150, 30, 30);
    
35.     //3.设置按钮背景图片
    
36.     [shang setBackgroundImage:[UIImage imageNamed:@"top_normal"] forState:UIControlStateNormal];
    
37.     [shang setBackgroundImage:[UIImage imageNamed:@"top_highlighted"] forState:UIControlStateHighlighted];
    
38.     //4.监听按钮点击事件
    
39.     [shang addTarget:self action:@selector(up) forControlEvents:UIControlEventTouchUpInside];
    
40.     //5.添加到view
    
41.     [self.view addSubview:shang];
    
42.    
    
43.    
    
44. }
    
45. -(IBAction)up{
    
46. CGRect rect = self.btn.frame;      //为什么这样不行呢
    
47. rect.origin.y-=10;
    
48. self.btn.frame=rect;
    
49.    
    
50. }
    
51. - (void)didReceiveMemoryWarning {
    
52.     [super didReceiveMemoryWarning];
    
53.     // Dispose of any resources that can be recreated.
    
54. }
    
55. 
    
56. @end
    

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为啥我这样不行呢 望大神告知啊

1. 
   
2. #import "ViewController.h"
   
3. 
   
4. @interface ViewController ()
   
5. 
   
6. @end
   
7. 
   
8. @implementation ViewController
   
9. 
   
10. - (void)viewDidLoad {
    
11.     [super viewDidLoad];
    
12.     // Do any additional setup after loading the view, typically from a nib.
    
13. #pragma mark - 图片按钮的创建
    
14.    
    
15.     //1.创建按钮
    
16.     UIButton *btn = [UIButton buttonWithType:UIButtonTypeCustom];
    
17.     //2.设置frame
    
18.     btn.frame=CGRectMake(50, 50, 50, 50);
    
19.     //3.设置按钮图片
    
20.     [btn setBackgroundImage:[UIImage imageNamed:@"biaoqingdi"] forState:UIControlStateNormal];
    
21.     [btn setBackgroundImage:[UIImage imageNamed:@"danteng"] forState:UIControlStateHighlighted];
    
22.     //4.设置图片文字
    
23.     [btn setTitle:@"别点我" forState:UIControlStateNormal];
    
24.     [btn setTitle:@"真点了" forState:UIControlStateHighlighted];
    
25.     //5.设置按钮文字颜色
    
26.     [btn setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
    
27.     [btn setTitleColor:[UIColor whiteColor] forState:UIControlStateHighlighted];
    
28.     //6.添加到view
    
29.     [self.view addSubview:btn];
    
30. #pragma mark - 向上
    
31.     //1.创建按钮
    
32.     UIButton *shang = [UIButton buttonWithType:UIButtonTypeCustom];
    
33.     //2.设置frame
    
34.     shang.frame = CGRectMake(150, 150, 30, 30);
    
35.     //3.设置按钮背景图片
    
36.     [shang setBackgroundImage:[UIImage imageNamed:@"top_normal"] forState:UIControlStateNormal];
    
37.     [shang setBackgroundImage:[UIImage imageNamed:@"top_highlighted"] forState:UIControlStateHighlighted];
    
38.     //4.监听按钮点击事件
    
39.     [shang addTarget:self action:@selector(up) forControlEvents:UIControlEventTouchUpInside];
    
40.     //5.添加到view
    
41.     [self.view addSubview:shang];
    
42.    
    
43.    
    
44. }
    
45. -(IBAction)up{
    
46. CGRect rect = self.btn.frame;      //为什么这样不行呢
    
47. rect.origin.y-=10;
    
48. self.btn.frame=rect;
    
49.    
    
50. }
    
51. - (void)didReceiveMemoryWarning {
    
52.     [super didReceiveMemoryWarning];
    
53.     // Dispose of any resources that can be recreated.
    
54. }
    
55. 
    
56. @end
    

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