CoreAnimation-06-CAKeyframeAnimation 相关代码

 

• • - (void)awakeFromNib{    

        iMV = [[UIImageView alloc] initWithFrame:CGRectMake(100, 100, 100, 100)];

        iMV.image = [UIImage imageNamed:@"c"];

        [self addSubview:iMV];

        NSLog(@"%@",NSStringFromCGRect([[self.subviews firstObject] layer].bounds));

    }

  • 使用成员属性保存贝瑟尔路径

  @property (nonatomic, strong) UIBezierPath *path;

  • 监听触摸事件的状态，绘制贝瑟尔曲线

    • 开始

    //确定起点
    - (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
    {
    	//获取当前触摸点
    	UITouch *touch = [touches anyObject];
    	CGPoint curretnPoint = [touch locationInView:self];
    
    	//创建路径
    	UIBezierPath *path = [UIBezierPath bezierPath];
    	[path moveToPoint:curretnPoint];
    	//保存路径
    	self.path = path;
    }

    • 移动

    //添加线条
    - (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
    {
    	//获取当前触摸点
    	UITouch *touch = [touches anyObject];
    	CGPoint currentPoint = [touch locationInView:self];
    	//添加线条
    	[self.path addLineToPoint:currentPoint];
    	//重绘，将曲线显示到图层上
    	[self setNeedsDisplay];
    }

    • 结束（创建动画）

    - (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
    {
    	//创建动画
    	CAKeyframeAnimation *animation = [CAKeyframeAnimation animation];
    
    	//指定执行动画的属性，
    	animation.keyPath = @"position";
    	//设置动画的执行路径
    	animation.path = self.path.CGPath;
    
    	//设置动画的执行时间
    	animation.duration = 1;
    	//设置动画的重复次数
    	animation.repeatCount = MAXFLOAT;
    
    	//将动画添加到对应的图层上
    	[[[self.subviews firstObject] layer] addAnimation:animation forKey:nil];
    }

  • 将路径显示到图层上

  //绘制路径
  - (void)drawRect:(CGRect)rect
  {
  	[self.path stroke];
  }