iOS中的四中触摸事件的详解 - 平移- 捏合 - 滑动(TouchesBegan,touchesMoved,touchesEnded,touchesCancelled)

RootViewController

#import "RootViewController.h"
#import "TouchView.h"
#import "PanView.h"
#import "PinchView.h"
@interface RootViewController ()

@end

@implementation RootViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    
//    TouchView *greenView = [[TouchView alloc] initWithFrame:CGRectMake(60, 184, 200, 200)];
//    greenView.layer.cornerRadius = greenView.frame.size.width/2;
//    greenView.backgroundColor = [UIColor greenColor];
//    
//    [self.view addSubview:greenView];
//    [greenView release];
//    PanView *greenView = [[PanView alloc] initWithFrame:CGRectMake(60, 184, 200, 200)];
//    greenView.layer.cornerRadius = greenView.frame.size.width/2;
//    greenView.backgroundColor = [UIColor greenColor];
//    
//    [self.view addSubview:greenView];
//    [greenView release];
    PinchView *redView = [[PinchView alloc] initWithFrame:CGRectMake(20, 40, 280, 500)];
    redView.backgroundColor = [UIColor redColor];
    
    [self.view addSubview:redView];
    [redView release];
    
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

/*
#pragma mark - Navigation

// In a storyboard-based application, you will often want to do a little preparation before navigation
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
    // Get the new view controller using [segue destinationViewController].
    // Pass the selected object to the new view controller.
}
*/
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
  UIView *view = self.view.subviews[0];
    view.backgroundColor = [UIColor redColor];
}
@end

TouchView.m

#import "TouchView.h"
#import "UIColor+Creat.h"
@implementation TouchView

/*
 为什么定义UIView的子类?是因为当我们想让Uiview响应触摸事件的话,需要让它的.m文件中实现几个方法,UIView不能在其.m文件中实现这几个方法,因此需要定义UIView的子类
 
 
 如果想让一个视图多个触摸事件作出响应,需要实现依稀几个能够响应触摸事件的方法
 
*/


/**刚开始触摸的时候触发(手指刚碰到视图)*/
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{

    //touches 存储手指点击对象,对应的类是UITouch
    //1.获取手指点击的点
    UITouch *touch = [touches anyObject]; // 从集合中快速去除点击的对象
    
    //2.获取点击的次数
    if (1 == touch.tapCount) {
        //当识别是单击操作是,延迟执行,看是否是双击操作
        [self performSelector:@selector(changeSelfColor) withObject:nil afterDelay:0.3];
        //[self changeSelfColor];
    }else if(2 == touch.tapCount){
        //当识别是双击操作时,取消单击操作
        [NSObject cancelPreviousPerformRequestsWithTarget:self selector:@selector(changeSelfColor) object:nil];
        
        
        [self changeSupColor];
    }
}
//当手指在视图内移动的时候触发(前提是手指还未离开视图)
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
          NSLog(@"%s,%d", __FUNCTION__,__LINE__);
    
}
//当手机离开视图时,即触摸结束.
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event{
//     NSLog(@"%s,%d", __FUNCTION__,__LINE__);
//    [self changeSupColor];
//    [self changeSelfFrame];
}
//当触摸取消时触发(触发被意外中断,比如有电话接入)
- (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event
{
     NSLog(@"%s,%d", __FUNCTION__,__LINE__);
}
//修改自身视图颜色
- (void)changeSelfColor{
    self.backgroundColor = [UIColor randomeColor];
}
//修改父视图颜色
- (void)changeSupColor{
    self.superview.backgroundColor = [UIColor randomeColor];
}
//修改自身位置
- (void)changeSelfFrame
{
    self.center = CGPointMake(arc4random() % 101 + 100, arc4random() % 301 + 100);
}
//实现单击,双击
@end

PanView.m

#import "PanView.h"

@implementation PanView

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
    //1.获取手指对象
    UITouch *touch = [touches anyObject];
    //2.获取手指当前位置
   CGPoint currentPoint = [touch locationInView:self];
    //3.获取手指之前的位置
    CGPoint previousPoint = [touch previousLocationInView:self];
    
    //4.计算移动的增量
    CGFloat dx = currentPoint.x - previousPoint.x;
    CGFloat dy = currentPoint.y - previousPoint.y;
    //修改视图位置
    self.center = CGPointMake(self.center.x + dx, self.center.y + dy);
}
@end

PinchView.m

#import "PinchView.h"

@implementation PinchView

- (instancetype)initWithFrame:(CGRect)frame
{
    if(self = [super initWithFrame:frame])
    {
        //iOS 支持多点触摸,只不过默认的是单点触摸
        self.multipleTouchEnabled = YES;
    }
    return self;
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event{
   
    if (1 == [touches count]) {
        return; // 如果触摸视图只有一点,则不捏合
    }
    //1.获取手指对象
    NSArray *allTouch = [touches allObjects];
    //不用下标的好处,不会造成程序的崩溃(数组下标越界)
    UITouch *firstTouch = [allTouch firstObject];
    UITouch *secondTouch = [allTouch lastObject];
    
    //2获取两个手指对象当前位置
    CGPoint currentFirstPoint = [firstTouch locationInView:self];
    CGPoint currentSecondPoint = [secondTouch locationInView:self];
    //3.获取之前的手指的位置
    
    CGPoint previousFirstPoint = [firstTouch previousLocationInView:self];
    CGPoint previousSecondPoint = [secondTouch previousLocationInView:self];
    
    //4.计算当前两个手指的距离
    CGFloat currentDistance = [self distanceFromPoint:currentFirstPoint toPoint:currentSecondPoint];
    //5.计算捏合前两个手指的距离
    CGFloat previousDistance = [self distanceFromPoint:previousFirstPoint toPoint:previousSecondPoint];
    
    //6.求出牛和前后两个捏合的比例
    CGFloat rate = currentDistance / previousDistance;
    
    //7.缩放如果视图大小变化,并且想保持中心点不变,修改bounds即可
    self.bounds = CGRectMake(0, 0, self.bounds.size.width * rate, self.bounds.size.height * rate);
    
   
    
}
//计算两个点的距离
- (CGFloat)distanceFromPoint:(CGPoint)fromPoint toPoint:(CGPoint)toPoint{
    
    CGFloat dx = fromPoint.x - toPoint.x;
    CGFloat dy = fromPoint.y - toPoint.y;
    
    return sqrt(dx * dx + dy * dy);
    
}
@end