UIGesture基础手势

下面介绍的是缩放手势和捏合手势:
直接上代码:
 1 #import "ViewController.h"
 2 
 3 @interface ViewController ()<UIGestureRecognizerDelegate>
 4 
 5 @end
 6 
 7 @implementation ViewController
 8 
 9 - (void)viewDidLoad {
10     [super viewDidLoad];
11     // Do any additional setup after loading the view, typically from a nib.
12     
13     //如果需要同时旋转和缩放我们还需要实现一个协议UIGestureRecognizerDelegate
14     
15     
16     UIImage *image = [UIImage imageNamed:@"2.jpg"];
17     
18     UIImageView *imageView = [[UIImageView alloc]init];
19     imageView.frame = CGRectMake(100, 200, 300, 400);
20     imageView.userInteractionEnabled = YES;
21     imageView.image = image;
22     [self.view addSubview:imageView];
23     
24     //添加缩放手势(捏合手势)
25     _pinGes = [[UIPinchGestureRecognizer alloc]initWithTarget:self action:@selector(pinchAct:)];
26     
27     [imageView addGestureRecognizer:_pinGes];
28     
29     //创建旋转手势
30     _rotGes = [[UIRotationGestureRecognizer alloc]initWithTarget:self action:@selector(RotGes:)];
31     
32     [imageView addGestureRecognizer:_rotGes];
33     
34     //设置协议代理
35     _pinGes.delegate = self;
36     _rotGes.delegate = self;
37     
38 }
39 
40 - (void)pinchAct:(UIPinchGestureRecognizer *)pin{
41     //获取监控图像视图(也就是上面的imageView对象)
42     UIImageView *Iview = (UIImageView *)pin.view;
43     //对图像视图对象进行矩阵变换计算并赋值
44     // transform 表示图形的变换
45     //CGAffineTransformScale 通过缩放的方式产生一个新矩阵
46     //p1 原来的矩阵
47     //p2 x方向的的缩放比例
48     //p3 y方向的缩放比例
49     Iview.transform = CGAffineTransformScale(Iview.transform, pin.scale, pin.scale);
50     
51     
52     //将缩放值归位为单位值
53     pin.scale = 1;
54     
55 }
56 
57 - (void)RotGes:(UIRotationGestureRecognizer *)rotGes{
58     
59     //获取旋转对象
60     UIImageView *Iview = (UIImageView *)rotGes.view;
61     //计算旋转变化并赋值
62     Iview.transform = CGAffineTransformRotate(Iview.transform, rotGes.rotation);
63     
64     //选择角度清零;
65     rotGes.rotation = 0;
66     
67     
68 }
69 //实现协议方法
70 //是否可以同时响应俩个手势
71 //如果返回值为YES 可以同时响应;
72 -(BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer{
73     
74     return YES;
75 }
这样就可以简单的实现对视图的缩放(捏合)和旋转.