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:

#import "ViewController.h"

@interface ViewController ()<UIGestureRecognizerDelegate>

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    
    //如果需要同时旋转和缩放我们还需要实现一个协议UIGestureRecognizerDelegate
    
    
    UIImage *image = [UIImage imageNamed:@"2.jpg"];
    
    UIImageView *imageView = [[UIImageView alloc]init];
    imageView.frame = CGRectMake(100, 200, 300, 400);
    imageView.userInteractionEnabled = YES;
    imageView.image = image;
    [self.view addSubview:imageView];
    
    //添加缩放手势(捏合手势)
    _pinGes = [[UIPinchGestureRecognizer alloc]initWithTarget:self action:@selector(pinchAct:)];
    
    [imageView addGestureRecognizer:_pinGes];
    
    //创建旋转手势
    _rotGes = [[UIRotationGestureRecognizer alloc]initWithTarget:self action:@selector(RotGes:)];
    
    [imageView addGestureRecognizer:_rotGes];
    
    //设置协议代理
    _pinGes.delegate = self;
    _rotGes.delegate = self;
    
}

- (void)pinchAct:(UIPinchGestureRecognizer *)pin{
    //获取监控图像视图(也就是上面的imageView对象)
    UIImageView *Iview = (UIImageView *)pin.view;
    //对图像视图对象进行矩阵变换计算并赋值
    // transform 表示图形的变换
    //CGAffineTransformScale 通过缩放的方式产生一个新矩阵
    //p1 原来的矩阵
    //p2 x方向的的缩放比例
    //p3 y方向的缩放比例
    Iview.transform = CGAffineTransformScale(Iview.transform, pin.scale, pin.scale);
    
    
    //将缩放值归位为单位值
    pin.scale = 1;
    
}

- (void)RotGes:(UIRotationGestureRecognizer *)rotGes{
    
    //获取旋转对象
    UIImageView *Iview = (UIImageView *)rotGes.view;
    //计算旋转变化并赋值
    Iview.transform = CGAffineTransformRotate(Iview.transform, rotGes.rotation);
    
    //选择角度清零;
    rotGes.rotation = 0;
    
    
}
//实现协议方法
//是否可以同时响应俩个手势
//如果返回值为YES 可以同时响应;
-(BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer{
    
    return YES;
}

这样就可以简单的实现对视图的缩放(捏合)和旋转.