1、UIGestureRecognizer 介绍

• UIPanGestureRecognizer（拖动）

• UIPinchGestureRecognizer（捏合）

• UIRotationGestureRecognizer（旋转）

• UITapGestureRecognizer（点按）

• UILongPressGestureRecognizer（长按）

• UISwipeGestureRecognizer（轻扫）

UIGestureRecognizer 的继承关系如下：

2、使用

//
//  ViewController.m
//  testOfGestureRecognizer
//
//  Created by Bobby on 16/9/6.
//  Copyright © 2016年 Bobby. All rights reserved.
//

#import "ViewController.h"

@interface ViewController ()<UIGestureRecognizerDelegate>
{
    UIImageView * imageView;
}

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];

    [self createImageView];
    [self createTapGesture];
    [self createPinchGesture];
    [self createRotationGesture];
    [self cretePanGesture];
    [self createLongPreessGesture];
    [self createSwipGesture];

}

- (void)createImageView{
    if (!imageView) {
        imageView = [[UIImageView alloc]initWithImage:[UIImage imageNamed:@"image"]];
        [self.view addSubview:imageView];
        imageView.frame = CGRectMake(100, 100, 150, 100);
        imageView.center = self.view.center;
        imageView.userInteractionEnabled = YES;
    }
}

- (void)createTapGesture{

    UITapGestureRecognizer * tapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapClick:)];
//  点击次数 1表示单击 2 表示 双击(快速双击)
    tapGesture.numberOfTapsRequired = 1;
//  tapGesture.numberOfTapsRequired = 2;
    
    //设置手指的个数
    tapGesture.numberOfTouchesRequired = 2;
    // 按住 option/alt  就 模拟器上就会出来两个小圆圈就相当于两个手指

    [imageView addGestureRecognizer:tapGesture];
    
}
- (void)tapClick:(UITapGestureRecognizer *)tap {
    self.view.backgroundColor = [UIColor colorWithRed:arc4random()%256/255.0 green:arc4random()%256/255.0 blue:arc4random()%256/255.0 alpha:1];
}


- (void)createPinchGesture{

    UIPinchGestureRecognizer *pinch = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(pinchClick:)];
    
    //一个视图上可以加 多个手势的 不过我们一般加1个或者2两个
    //加的太多了可能会产生影响的
    
    pinch.delegate = self;
    
    [imageView addGestureRecognizer:pinch];
}
//捏合就是 放大 / 缩小
- (void)pinchClick:(UIPinchGestureRecognizer *)pinch {
    
    NSLog(@"pinch.scale:%f",pinch.scale);
    //我们可以通过 transform 仿射变换 进行 放大 缩小
    //可以pinch 的比例 scale
    
    //相对于当前的_imageView.transform 进行缩放
    
    imageView.transform = CGAffineTransformScale(imageView.transform, pinch.scale, pinch.scale);
    
    //重置捏合手势的比例 每次都应该相对于当前的
    pinch.scale = 1;//下次 相对比例应该从1 开始
}

- (void)createRotationGesture{

    UIRotationGestureRecognizer *rotation = [[UIRotationGestureRecognizer alloc]  initWithTarget:self action:@selector(rotaion:)];
    
    //如果要想两个手势同时生效那么需要设置代理
    rotation.delegate = self;
    [imageView addGestureRecognizer:rotation];
}

- (void)rotaion:(UIRotationGestureRecognizer *)rotation {
    //transform 属性 可以设置旋转
    
    //相对于 _imageView.transform  当前的弧度  进行 旋转
    imageView.transform = CGAffineTransformRotate(imageView.transform, rotation.rotation);
    
    //重置 旋转的弧度 相对于当前的 从0 开始
    //重置0弧度
    rotation.rotation = 0;
}
//拖动/移动手势
- (void)cretePanGesture{
    UIPanGestureRecognizer *pan = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(panClick:)];
    //增加手势
    [imageView addGestureRecognizer:pan];
    
}

- (void)panClick:(UIPanGestureRecognizer *)pan {
    //获取 拖动手势的偏移量
    //手势偏移量 相对的视图 要和 _imageView相对的坐标视图保持一致（相对的都是同一个视图）
    CGPoint offSet = [pan translationInView:self.view];//相对于self.view的偏移量
    //修改中心点位置
    CGPoint point = imageView.center;
    imageView.center = CGPointMake(point.x+offSet.x, point.y+offSet.y);
    //把手势的偏移量 每次重置(0,0)CGPointZero
    [pan setTranslation:CGPointZero inView:self.view];
}


- (void)createLongPreessGesture{
    UILongPressGestureRecognizer *lPress = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(longPress:)];
    
    [imageView addGestureRecognizer:lPress];
    
}

/*
 长按 手势 默认会触发两次 开始的时候一次 长按结束的时候再触发一次
 */
- (void)longPress:(UILongPressGestureRecognizer *)longPress {
    //NSLog(@"长按手势");
    //判断手势的状态
    if (longPress.state == UIGestureRecognizerStateBegan) {//手势开始的时候
        NSLog(@"长按手势开始");
    }else if (longPress.state == UIGestureRecognizerStateEnded) {
        //手势结束的状态
        NSLog(@"长按手势结束");
    }
}

- (void)createSwipGesture{

    UISwipeGestureRecognizer *swipe = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(swipe:)];
    
    //滑动手势 需要设置 方向
    //如果 需要四个方向有效 那么必须要加4手势在_imageView上
    swipe.direction  =  UISwipeGestureRecognizerDirectionRight;
    
    [imageView addGestureRecognizer:swipe];
}

- (void)swipe:(UISwipeGestureRecognizer *)swipe {
    NSLog(@"滑动手势");
    CGPoint center = imageView.center;
    switch (swipe.direction) {
        case UISwipeGestureRecognizerDirectionRight://向右
        {
            NSLog(@"向右滑动");
            imageView.center = CGPointMake(center.x+100, center.y);
        }
            break;
        case UISwipeGestureRecognizerDirectionLeft://向左
        {
            NSLog(@"向左滑动");
            imageView.center = CGPointMake(center.x-100, center.y);
        }
            break;
        case UISwipeGestureRecognizerDirectionUp://向上
        {
            NSLog(@"向上滑动");
            imageView.center = CGPointMake(center.x, center.y-100);
            
        }
            break;
        case UISwipeGestureRecognizerDirectionDown://向下
        {
            NSLog(@"向下滑动");
            imageView.center = CGPointMake(center.x, center.y+100);
            
        }
            break;
            
        default:
            break;
    }
}

//默认情况  增加的多个手势 同时只能有一个生效
/*
 如果要想让两个没有相互影响的手势同时生效 那么必须要设置这两个手势的代理，两个手势委托代理来处理就可以了
 代理需要遵守协议
 
 比如 旋转和捏合没有相互影响可以设置同时生效 那么就需要设置旋转手势的代理和捏合手势的代理
 同一个代理
 */
#pragma mark - UIGestureRecognizerDelegate协议
//是否允许 两个手势同时生效
//NO不允许
//YES允许
//两个手势 必须要设置代理

- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer {
    NSLog(@"first:%@",[gestureRecognizer class]);
    NSLog(@"second:%@",[otherGestureRecognizer class]);
    return YES;
}

@end