/*    定義屬性 */@interface ViewController (){    CGPoint _startPoint; //開始點擊的點    CGPoint _endPoint; //結束點擊的點        UILabel *_label1; //顯示當前觸摸的狀態的標簽    UILabel *_label2;    UILabel *_label3;    UILabel *_label4;    UIImageView *_imageView; //笑臉圖片}/*    觸摸事件UITouch的系列方法如下所示 <一>到<四> */#PRagma mark <一> 當一個或多個手指觸碰屏幕時，發送touchesBegan:withEvent:消息-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{    _label1.text = @"觸摸 開始 ";        //1. 首先獲取觸摸屏幕的手指    UITouch * touch = [touches anyObject];        //2. 點擊的當前點的坐標    CGPoint point = [touch locationInView:self.view];    _label2.text = [NSString stringWithFormat:@"當前點得坐標:x=%.1f, y=%.1f",point.x,point.y];        //4. 獲取觸摸屏幕的次數    int tapCount = touch.tapCount;    //5. 獲取觸摸屏幕的手指根數    int fingerCount = touches.count;        _label3.text = [NSString stringWithFormat:@"觸摸屏幕次數為%i, 觸摸的手指數為%i",tapCount,fingerCount];        //6. 當前視圖默認只支持單點觸摸 如果想添加多點觸摸 必須開啟多點觸摸模式    self.view.multipleTouchEnabled = YES;        //7.1. 得到開始點擊的點,得到最后點擊的點，計算一下，看看做了什么操作    _startPoint = [touch locationInView:self.view];    _label4.text = @"";}#pragma mark <二> 當一個或多個手指在屏幕上移動時，發送touchesMoved:withEvent:消息-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event{    _label1.text = @"觸摸 move...";    CGPoint point = [[touches anyObject] locationInView:self.view];    _label2.text = [NSString stringWithFormat:@"當前點得坐標:x=%.1f, y=%.1f",point.x,point.y];}#pragma mark <三> 當一個或多個手指離開屏幕時，發送touchesEnded:withEvent:消息-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event{    _label1.text = @"觸摸 結束";    CGPoint point = [[touches anyObject] locationInView:self.view];        //3. 判斷是否進入了圖片范圍內    if (CGRectContainsPoint(_imageView.frame, point)) {        _label2.text = @"停留在笑臉圖片范圍內";    }    else    {        _label2.text = @"停留在笑臉圖片外面";    }        //7.2 計算開始到結束偏移量    float distanceX = fabsf(point.x - _startPoint.x);    //獲取手指縱向移動的偏移量    float distanceY = fabsf(point.y - _startPoint.y);        _label4.text = [NSString stringWithFormat:@"x偏移了%.1f，y方向偏移了%.1f",distanceX,distanceY];        _startPoint = CGPointZero;}#pragma mark <四> 當觸摸序列被諸如電話呼入這樣的系統事件打斷所意外取消時，發送touchesCancelled:withEvent:消息-(void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event{    _label1.text = @"觸摸 取消";}