iOS开发之手势事件(UiGestureRecognizer)

我们在开发过程中为了提高用户体验,以及实现更好的用户交互往往会使用UiGestureRecognizer(手势识别器)这一类

其实UiGestureRecognizer这一类并不复杂,简单来说这就是一个特殊的触摸事件,UiGestureRecognizer是一个父类,而实际操作中我们要使用它的子类,较为常用的有以下几种:

UITapGestureRecognizer	轻拍手势
UISwipeGestureRecognizer	轻扫手势
UILongPressGestureRecognizer	长按手势
UIPanGestureRecognizer	平移手势
UIPinchGestureRecognizer	捏合（缩放）手势
UIRotationGestureRecognizer	旋转手势
UIScreenEdgePanGestureRecognizer	屏幕边缘平移

UITapGestureRecognizer(轻拍手势)

手势的用法大同小异，我们以UITapGestureRecognizer（轻拍手势）为例
首先我们在viewDidLoad中建立一个测试View

- (void)viewDidLoad {
    [super viewDidLoad];
    self.view.backgroundColor = [UIColor whiteColor];
    
    _testView = [[UIView alloc]initWithFrame:CGRectMake(50, 50, 314, 500)];
    _testView.backgroundColor = [UIColor orangeColor];
    
    [self.view addSubview:_testView];
}

效果如图：

创建testView

接下来我们需要在viewDidLoad方法中给这个view添加手势

//创建手势 使用initWithTarget:action:的方法创建
    UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(tapView:)];
    
    //设置属性
    //tap 手势一共两个属性，一个是设置轻拍次数，一个是设置点击手指个数
    //设置轻拍次数
    tap.numberOfTapsRequired = 2;
    //设置手指字数
    tap.numberOfTouchesRequired = 2;
    
    //别忘了添加到testView上
    [_testView addGestureRecognizer:tap];

实现触发事件，此处触发的事件是改变testView的颜色

#pragma mark --- UITapGestureRecognizer 轻拍手势事件 ---

-(void)tapView:(UITapGestureRecognizer *)sender{
    //设置轻拍事件改变testView的颜色
    _testView.backgroundColor = [UIColor colorWithRed:arc4random()%256/255.0 green:arc4random()%256/255.0 blue:arc4random()%256/255.0 alpha:1];
}

实现的效果如下

点击后颜色改变

UISwipeGestureRecognizer (轻扫手势)

我们仍然使用testView这一场景

//创建手势
  UISwipeGestureRecognizer *swipe = [[UISwipeGestureRecognizer alloc]initWithTarget:self action:@selector(swipeView:)];
//设置属性，swipe也是有两种属性设置手指个数及轻扫方向
swipe.numberOfTouchesRequired = 2;
    //设置轻扫方向(默认是从左往右)
    //direction是一个枚举值有四个选项，我们可以设置从左往右，从右往左，从下往上以及从上往下
  //设置轻扫方向(默认是从左往右)
    swipe.direction = UISwipeGestureRecognizerDirectionLeft;
//    [_redView addGestureRecognizer:swipe];

触发的事件为：

#pragma mark swipe轻扫手势事件
-(void)swipeView:(UISwipeGestureRecognizer *)sender{
    _testView.backgroundColor = [UIColor colorWithRed:arc4random()%256/255.0 green:arc4random()%256/255.0 blue:arc4random()%256/255.0 alpha:1];
}

UILongPressGestureRecognizer(长按手势)

 UILongPressGestureRecognizer *longPress = [[UILongPressGestureRecognizer alloc]initWithTarget:self action:@selector(longPress:)];
    //属性设置
    //最小长按时间
    longPress.minimumPressDuration = 2;
        [_testView addGestureRecognizer:longPress];

触发事件：

#pragma mark langPress 长按手势事件
-(void)longPress:(UILongPressGestureRecognizer *)sender{
    //进行判断,在什么时候触发事件
    if (sender.state == UIGestureRecognizerStateBegan) {
        NSLog(@"长按状态");
//改变testView颜色
        _testView.backgroundColor = [UIColor colorWithRed:arc4random()%256/255.0 green:arc4random()%256/255.0 blue:arc4random()%256/255.0 alpha:1];
    }
}

UIPanGestureRecognizer(平移手势)

创建手势

 UIPanGestureRecognizer *pan = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(panView:)];
    
 [_testView addGestureRecognizer:pan];

触发事件

#pragma mark pan   平移手势事件
-(void)panView:(UIPanGestureRecognizer *)sender{
    CGPoint point = [sender translationInView:_testView];
//    sender.view.transform = CGAffineTransformMake(1, 0, 0, 1, point.x, point.y);
    
//平移一共两种移动方式
 //第一种移动方法:每次移动都是从原来的位置移动
//    sender.view.transform = CGAffineTransformMakeTranslation(point.x, point.y);
    
    //第二种移动方式:以上次的位置为标准(移动方式 第二次移动加上第一次移动量)
    sender.view.transform = CGAffineTransformTranslate(sender.view.transform, point.x, point.y);
    //增量置为o
    [sender setTranslation:CGPointZero inView:sender.view];
    
     _testView.backgroundColor = [UIColor colorWithRed:arc4random()%256/255.0 green:arc4random()%256/255.0 blue:arc4random()%256/255.0 alpha:1];
    
}

UIScreenEdgePanGestureRecognizer(屏幕边缘平移手势)

创建手势

    UIScreenEdgePanGestureRecognizer *screenEdgePan = [[UIScreenEdgePanGestureRecognizer alloc]initWithTarget:self action:@selector(screenEdgePanView:)];

    //注意:,使用屏幕边界平移手势,需要注意两点
    //1. 视图位置(屏幕边缘)
    //2. 设置edges属性
     // 设置屏幕边缘手势支持方法
    screenEdgePan.edges = UIRectEdgeLeft;
    //属性设置
  [_testView addGestureRecognizer:screenEdgePan];

触发事件

#pragma mark screenEdgePan 屏幕边界平移事件
-(void)screenEdgePanView:(UIScreenEdgePanGestureRecognizer *)sender{
    
    //计算偏移量
    CGPoint point = [sender translationInView:_testView];
    //进行平移
    sender.view.transform = CGAffineTransformMakeTranslation(point.x, point.y);
    
}

UIPinchGestureRecognizer(捏合手势)

创建手势

  UIPinchGestureRecognizer *pinch = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(pinchView:)];
 [_testView addGestureRecognizer:pinch];

触发事件

#pragma mark pinch 捏合手势事件
-(void)pinchView:(UIPinchGestureRecognizer *)sender{
    //scale 缩放比例
//    sender.view.transform = CGAffineTransformMake(sender.scale, 0, 0, sender.scale, 0, 0);
    //每次缩放以原来位置为标准
//    sender.view.transform = CGAffineTransformMakeScale(sender.scale, sender.scale);
   
    //每次缩放以上一次为标准
    sender.view.transform = CGAffineTransformScale(sender.view.transform, sender.scale, sender.scale);
    //重新设置缩放比例 1是正常缩放.小于1时是缩小(无论何种操作都是缩小),大于1时是放大(无论何种操作都是放大)
    sender.scale = 1;
   
}

UIRotationGestureRecognizer(旋转手势)

创建手势

 UIRotationGestureRecognizer *rotation = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:@selector(rotationView:)];
    
 [_testView addGestureRecognizer:rotation];

触发事件

-(void)rotationView:(UIRotationGestureRecognizer *)sender{
//    sender.view.transform = CGAffineTransformMake(cos(M_PI_4), sin(M_PI_4), -sin(M_PI_4), cos(M_PI_4), 0, 0);
    //捏合手势两种改变方式
    //以原来的位置为标准
//    sender.view.transform = CGAffineTransformMakeRotation(sender.rotation);//rotation 是旋转角度
    
    //两个参数,以上位置为标准
    sender.view.transform = CGAffineTransformRotate(sender.view.transform, sender.rotation);
    //消除增量
    sender.rotation = 0.0;
    
}

合理的运用手势会使我们的app拥有更好的体验，但是在使用手势的同时也要注意避免手势和手势间，以及手势和其他控件间的冲突。