UI之touchEvent

用背景色的随机改变来验证touchEvent的效果

#import <UIKit/UIKit.h>

//引入头文件
#import "mainViewController.h"
@interface MangoTouchView : UIView

@end

#import "MangoTouchView.h"
@interface MangoTouchView ()
{
    CGPoint _point;
    UIView *_view;
}
@end
@implementation MangoTouchView
//重写init方法
- (instancetype)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        [self loadingCustomView];
    }
    return self;
}
- (void)loadingCustomView{
    self.backgroundColor  = [UIColor cyanColor];
    _view = [[UIView alloc]initWithFrame:CGRectMake(40, 130, 100, 40)];
    _view.backgroundColor = [UIColor lightGrayColor];
    [self addSubview:_view];
}
//触摸事件
//当点击到屏幕上时触发
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{
    //NSLog(@"%s",__FUNCTION__);
    // 从触摸手势集合中取出任意触摸点
    UITouch *touch = [touches anyObject];
    //通过触摸点在当前视图上的位置，返回触摸点的坐标
     _point = [touch locationInView:_view];
//    NSLog(@"%@",NSStringFromCGPoint(_point));
}
//当手指在屏幕上移动时就会调用
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event{
   //NSLog(@"%s",__FUNCTION__);
}
//当手指离开屏幕时触发
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event{
    //NSLog(@"%s",__FUNCTION__);    
    //把当前view设置为随机色,arc4random()%256值的区间（0~255），（0~255）/255计算出的是0.0到1.0区间的数
    self.backgroundColor = [UIColor colorWithRed:arc4random()%256/255.0f green:arc4random()%256/255.0f blue:arc4random()%256/255.0f alpha:1.0];
//    UITouch *end = [touches anyObject];
//    CGPoint endp = [end locationInView:self];
//    NSLog(@"%@",NSStringFromCGPoint(endp));
    UITouch *touch = [touches anyObject];
    CGPoint movepoint = [touch locationInView:_view];
    CGFloat offsetX = movepoint.x - _point.x;
    CGFloat offsetY = movepoint.y - _point.y;
    _view.center = CGPointMake(_view.center.x+offsetX, _view.center.y+offsetY);
}
//当来电话（上拉控制中心的时候）或者其他系统级别的事件（上拉控制中心的时候）打断时触发
- (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event{
      NSLog(@"%s",__FUNCTION__);
}

#import <UIKit/UIKit.h>
@interface mainViewController : UIViewController
@end

#import "mainViewController.h"
//引入头文件
#import "MangoTouchView.h"
@interface mainViewController ()
@end
@implementation mainViewController
//重写loadingView方法，加载当前视图控制器自带的view
- (void)loadView{
//    调用父类的初始化方法
    [super loadView];
//    用自定义的view覆盖自带view(self.view)
    self.view = [[MangoTouchView alloc]initWithFrame:self.view.frame];
}
- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    self.view.backgroundColor = [UIColor orangeColor];
    //创建mangoView，设置其跟self.view一样大
    MangoTouchView *mango = [[MangoTouchView alloc]initWithFrame:self.view.frame];
    //添加到根视图上
    [self.view addSubview:mango];
    //释放
    [mango release];
}