1、首先来介绍下触摸事件和手势识别器的利与弊
触摸事件和手势识别器二者之间有直接的关系
手势识别器是在触摸事件的基础上演变过来的
当我们用到触摸事件时 默认的uiview是没有什么效果的 只能自定义view才能实现事件的触摸
通常用到的方法如下：
– touchesBegan:withEvent:
– touchesMoved:withEvent:
– touchesEnded:withEvent:
- touchesCancelled:withEvent: 而手势识别器是在触摸事件的基础上而封装的
为什么要封装呢？因为直接touchs方法来定位手势比较麻烦。在还没有UIGestureRecognizer的时代，用touchs也可以计算出博文中说的几种常用手势：点，滑动，拖等等。这些手势都非常常用，每个开发者想要监视这些手势的时候都要自己判断一遍，每个人都在重复造*。那把这些手势封装出来标准化，就有了UIGestureRecognizer和它对应的子类手势了。 那为什么还要有touchs等方法存在呢？因为UIGestureRecognizer几种手势比较有限，有的游戏应用需要搞些特别的手势，那就用touchs这些方法来定义了。
2、使用手势步骤
使用手势很简单，分为两步：
创建手势实例。当创建手势时，指定一个回调方法，当手势开始，改变、或结束时，回调方法被调用。
添加到需要识别的View中。每个手势只对应一个View，当屏幕触摸在View的边界内时，如果手势和预定的一样，那就会回调方法。
ps：一个手势只能对应一个View，但是一个View可以有多个手势。
建议在真机上运行这些手势,模拟器操作不太方便，可能导致你认为手势失效。
3、手势的介绍
UITapGestureRecognizer （敲击）
UIPinchGestureRecognizer (捏合，由于缩放)
UIPanGestureRecognizer (拖拽)
UISwipeGestureRecognizer (轻扫)
UIRotationGestureRecognizer(旋转)
UILongPressGestureRecognizer(长按)
4、敲击手势的用法（其他手势类同）代码如下：
//创建手势识别对象
UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] init];
//连续敲击二次手势才能识别成功
tap.numberOfTapsRequired = ;
//需要一根手指触摸
tap.numberOfTouchesRequired = ;
//添加手势识别器对象到对应的uiview
[self.iconView addGestureRecognizer:tap]; //添加监听方法（识别到对应的手势就会监听事件）
[tap addTarget:self action:@selector(btClick:)];
5、缩放 + 旋转
#import "ViewController.h" @interface ViewController ()<UIGestureRecognizerDelegate>
@property (weak, nonatomic) IBOutlet UIImageView *iconView; @end @implementation ViewController - (void)viewDidLoad {
[super viewDidLoad];
self.iconView.userInteractionEnabled = YES;
// Do any additional setup after loading the view, typically from a nib.
[self testPichAndRoate];
} - (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
-(void) testPichAndRoate
{
//[self testPich];
[self testRoate];
}
-(void) testPich
{
UIPinchGestureRecognizer *pich = [[UIPinchGestureRecognizer alloc] init];
pich.delegate = self;
[self.iconView addGestureRecognizer:pich];
[pich addTarget:self action:@selector(pinchView:)];
}
-(void) pinchView:(UIPinchGestureRecognizer *)pinchView
{
pinchView.view.transform = CGAffineTransformScale(pinchView.view.transform, pinchView.scale, pinchView.scale);
pinchView.scale = ;//必写
}
-(void) testRoate
{
UIRotationGestureRecognizer *roate = [[UIRotationGestureRecognizer alloc] init];
roate.delegate = self;
[self.iconView addGestureRecognizer:roate];
[roate addTarget:self action:@selector(roateView:)];
}
-(void) roateView:(UIRotationGestureRecognizer *)roate
{
roate.view.transform = CGAffineTransformRotate(roate.view.transform, roate.rotation);
roate.rotation = ;//必写
}
@end
6、拖动
#import "ViewController.h" @interface ViewController ()
@property (weak, nonatomic) IBOutlet UIView *panView; @end @implementation ViewController - (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
UIPanGestureRecognizer *pan = [[UIPanGestureRecognizer alloc] init];
[self.panView addGestureRecognizer:pan];
[pan addTarget:self action:@selector(panTuoDong:)]; } - (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
-(void)panTuoDong:(UIPanGestureRecognizer *)pan
{
switch (pan.state) {
case UIGestureRecognizerStateBegan: // 开始触发手势 break; case UIGestureRecognizerStateEnded: // 手势结束 break; default:
break;
}
//在view上挪动的距离
CGPoint transtation = [pan translationInView:pan.view];
CGPoint center = pan.view.center;
center.x += transtation.x;
center.y += transtation.y;
pan.view.center = center; //清除挪动的距离
[pan setTranslation:CGPointZero inView:pan.view];
} @end