UI：触摸事件 与 事件的回应

事件分类：晃动、触摸、远程控制（如遥控器、红外控制）

触摸开始时候的方法（判断单击，双击，三击事件可以写在这里）

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{}

//触摸开始时候的方法 （）
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{
    NSLog(@"触摸开始");
    //点击的时候随机改变背景颜色
//    [self changeSelColor];
    //touches 存储触摸屏幕时的手指对象
    //UITouch 表示是一个手指类,每一个手指对象都是一个 UITouch 类型的对象
    //1.取出手指对象
    UITouch * aTouch = [touches anyObject];
    //2.根据点击的次数来进行相应的处理
    if (aTouch.tapCount == ) {
        NSLog(@"");//这里的永远不会打印出来，因为，触摸必定会点击到屏幕
    }
    if ( aTouch.tapCount == ) {
//        [self changeSelColor];
        //让单击操作延迟。看是否有双击事件操作
        [self performSelector:@selector(changeSelColor) withObject:nil afterDelay:0.3];
    }
    if (aTouch.tapCount == ) {
        [self changFatherColor];
        //双击操作的时候，取消改变自身颜色的操作
        [NSObject cancelPreviousPerformRequestsWithTarget:self selector:@selector(changeSelColor) object:nil];
    }
    if (aTouch.tapCount == ) {
        [self changSelfStation];//点击3次，改变自身的位置
    }
}

我们的双击，三击，单击事件 demo

手指还没有离开屏幕时候（在屏幕上移动手指）触发

-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event{}

触发结束时候，手指离开屏幕的那一时刻触发

-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event{}

触摸中断时候要触发的方法

-(void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event{}

随机改变颜色（一般写在一个方法的分类里，方便调用）

[UIColor  colorWithRed:arc4random()%256/255.0 green:arc4random()%256/255.0 blue:arc4random()%256/255.0 alpha:1.0];

UIEvent:事件,是由硬件捕捉的⼀一个表⽰示⽤用户操作设备的对象。 （触摸事件、晃动事件、远程控制事件）

触摸事件:⽤用户通过触摸设备屏幕操作对象、输⼊入数据。⽀支持多点 触摸,包含1个到多个触摸点

UIView⽀支持触摸事件(因为继承于UIResponder),⽽而且⽀支持多 点触摸。

我们视图上的Button 我们的程序怎么知道我们点击了？每一个程序都是一个 UIApplication 对象

yellowView.userInteractionEnabled = NO;黄色视图的用户交互属性被关闭。

当我们查找的时候，是一层一层去查找，当我们去响应的时候，是从响应的地方开始，往上提交

代码demo

---

//
//  AppDelegate.m

#import "AppDelegate.h"

@interface AppDelegate ()

@end

@implementation AppDelegate

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    self.window.backgroundColor = [UIColor whiteColor];
    [self.window makeKeyAndVisible];
    RootViewController * rootView = [[RootViewController alloc]init];
    self.window.rootViewController = rootView;
    [rootView release];

    return YES;
}
-(void)dealloc{
    [self release];
    [super dealloc];
}

mian.m

#import <UIKit/UIKit.h> @interface PinchView : UIView @end

PinchView.h

//
//  PinchView.m

#import "PinchView.h"

//捏合效果(在 touchesMoved 里面实现)
@implementation PinchView
//IOS 支出多点触控，只不过默认的是开启单点触控
//重写初始化方法，修改为支持多点触控
-(instancetype)initWithFrame:(CGRect)frame{
    self = [super initWithFrame:frame];
    if (self) {
        self.multipleTouchEnabled = YES;//支持多点触摸
    }
    return self;
}
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{

}
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event{
    //一旦发现是用一个手指在操作的话，则不进行下面的捏合操作
    if (touches.count == ) {
        return ;//结束下面的代码 （return 后面的代码永远不会被编译到）
    }
    //1.获取触摸屏的两个手指对象
    NSArray * allTouches = [touches allObjects];
    UITouch * firstTouch = [allTouches firstObject];//取出第一个手指对象
    UITouch * secondTouch = [allTouches lastObject];//取出第二个手指对象
    //2.获取捏合后手指的位置
    CGPoint currentPoint1 = [firstTouch locationInView:self];
    CGPoint currentPoint2 = [secondTouch locationInView:self];
    //3.获取手指捏合后的距离
    CGFloat currentDistance = [self destanceBetweenPoint1:currentPoint1 Ponit2:currentPoint2];
    //4.获取捏合之前的手指的位置
    CGPoint previousPoint1 = [firstTouch previousLocationInView:self];
    CGPoint previousPoint2 = [secondTouch previousLocationInView:self];
    //5.获取捏合之前的两手指之间的距离
    CGFloat previousDistance = [self destanceBetweenPoint1:previousPoint1 Ponit2:previousPoint2];
    //6.缩放比 (捏合后和捏合前的比例)
    CGFloat scale  = currentDistance/previousDistance;
    //7.修改视图的大小 修改 bounds 保持中心点不变
    self.bounds = CGRectMake(, , self.frame.size.width*scale, self.frame.size.height*scale);

    /*
     CGFloat ph1 = currentPoint1.y - currentPoint2.y;
    //捏合前的两手指位置
    CGPoint previousLocation1 = [firstTouch previousLocationInView:self];
    CGPoint previousLocation2 = [secondTouch previousLocationInView:self];
    //捏合前的两手指距离
    CGFloat ph2 = previousLocation1.y - previousLocation2.y;
    //计算比例
    CGFloat change = ph1/ph2;
    //得到缩放后的效果
    self.center = self.center;
    CGFloat w = self.frame.size.width * change;
    CGFloat h = self.frame.size.height * change;
    */

}
-(void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event{

}
-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event{

}

//利用勾股定理 计算两个点之间的距离
-(CGFloat)destanceBetweenPoint1:(CGPoint )point1 Ponit2:(CGPoint )point2{
    CGFloat dx = point1.x - point2.x;
    CGFloat dy = point1.y - point2.y;
    return sqrt(dx*dx + dy*dy);
}
@end

PinchView.m

//
//  TouchView.h

#import <UIKit/UIKit.h>
#import "UIColor+Addition.h"
#import "PanView.h"

@interface TouchView : UIView

-(void)changeSelColor;
-(void)changFatherColor;
-(void)changSelfStation;
@end

TouchView.h

//
//  TouchView.m

#import "TouchView.h"

@implementation TouchView

//对于 UIView 类的视图可以接受触摸事件，但是让他响应，必须实现以下的几个方法

//单击的时候改变自己的颜色，双击的时候改变父视图的颜色

//触摸开始时候的方法 （）
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{
    NSLog(@"触摸开始");
    //点击的时候随机改变背景颜色
//    [self changeSelColor];
    //touches 存储触摸屏幕时的手指对象
    //UITouch 表示是一个手指类,每一个手指对象都是一个 UITouch 类型的对象
    //1.取出手指对象
    UITouch * aTouch = [touches anyObject];
    //2.根据点击的次数来进行相应的处理
    if (aTouch.tapCount == ) {
        NSLog(@"");//这里的永远不会打印出来，因为，触摸必定会点击到屏幕
    }
    if ( aTouch.tapCount == ) {
//        [self changeSelColor];
        //让单击操作延迟。看是否有双击事件操作
        [self performSelector:@selector(changeSelColor) withObject:nil afterDelay:0.3];
    }
    if (aTouch.tapCount == ) {
        [self changFatherColor];
        //双击操作的时候，取消改变自身颜色的操作
        [NSObject cancelPreviousPerformRequestsWithTarget:self selector:@selector(changeSelColor) object:nil];
    }
    if (aTouch.tapCount == ) {
        [self changSelfStation];//点击3次，改变自身的位置
    }
}
//手指还没有离开屏幕  （手指移动的时候）
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event{
    //手指移动的时候，改变父视图的颜色
    [self changFatherColor];
}
//触摸中断的时候触发的事件 （例如，手机有电话了）
-(void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event{
    self.backgroundColor = [UIColor blackColor];
}
//触摸结束的时候触发的事件 （手指离开屏幕的时候）
-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event{
    //x 在 100-300    y 在 100 - 500
//    [self changSelfStation];
}

//改变自身视图的颜色
-(void)changeSelColor{
    self.backgroundColor = [UIColor randomColor];
}
//改变父视图的颜色
-(void)changFatherColor{
    self.superview.backgroundColor = [UIColor randomColor];
}
//改变自身的位置
-(void)changSelfStation{
    self.center = CGPointMake(arc4random()%((-+)+)*1.0, arc4random()%((-+)+)*1.0);
}

@end

TouchView.m

#import <UIKit/UIKit.h> @interface PanView : UIView @end

PanView.h

#import "PanView.h"

@implementation PanView

-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event{
    //1.获取触摸屏幕的手指对象
    UITouch * aTouch = [touches anyObject];
    //2.获取手指所在点移动之前的位置和移动之后的位置
    CGPoint currentLocation = [aTouch locationInView:self];//当前点位置，移动之后
    CGPoint previousLocation = [aTouch previousLocationInView:self];//原来点位置，移动之前的点位置
    //3.计算改变量
    CGFloat dx = currentLocation.x - previousLocation.x;
    CGFloat dy = currentLocation.y - previousLocation.y;
    //4.移动之后视图所在的位置（中心点）
    self.center = CGPointMake(self.center.x + dx, self.center.y + dy);

}
@end

PanView.m

#import <UIKit/UIKit.h>

@interface UIColor (Addition)
//声明类方法的随机色
+(UIColor * )randomColor;
@end

UIColor+Addition.h

#import "UIColor+Addition.h"

@implementation UIColor (Addition)

+(UIColor * )randomColor{
//    return [UIColor colorWithRed:arc4random()%256/255.0 green:arc4random()%256/255.0 blue:arc4random()%256/255.0 alpha:1.0];
    return [self colorWithRed:arc4random()%/255.0 green:arc4random()%/255.0 blue:arc4random()%/255.0 alpha:1.0];
}

@end

#import <UIKit/UIKit.h>

@interface RootViewController : UIViewController

@end

RootViewController.h

//
//  RootViewController.m

#import "RootViewController.h"
#import "TouchView.h"
#import "PanView.h"
#import "PinchView.h"

@interface RootViewController ()

@end

@implementation RootViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    //视图类都可以接触到触摸的事件
    self.view.backgroundColor = [UIColor grayColor];
    TouchView * redView = [[TouchView alloc]initWithFrame:CGRectMake(, , , )];
    redView.backgroundColor = [UIColor redColor];
    [self.view addSubview:redView];
    [redView release];

    PanView * yellowView = [[PanView alloc]initWithFrame:CGRectMake(, , , )];
    yellowView.backgroundColor = [UIColor yellowColor];
    [self.view addSubview:yellowView];
    [yellowView release];

    PinchView * greenView = [[PinchView alloc]initWithFrame:CGRectMake(, , , )];
    greenView.backgroundColor = [UIColor greenColor];
    [self.view addSubview:greenView];
    [greenView 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.
}
*/

@end