iOS学习笔记33 - 动画
一，核心动画
-(UIColor *)createColor{
CGFloat r = arc4random_uniform(255)/255.0;
CGFloat g = arc4random_uniform(255)/255.0;
CGFloat b = arc4random_uniform(255)/255.0;
CGFloat ap = arc4random_uniform(255)/255.0;
UIColor *color = [UIColor colorWithRed:r green:g blue:b alpha:ap];
return color;
}
- (void)viewDidLoad {
[super viewDidLoad];
self.layer = [CALayer layer];
self.layer.backgroundColor = [UIColor colorWithRed:1 green:1 blue:1 alpha:1].CGColor;
self.layer.position = CGPointMake(100, 100);
self.layer.bounds = CGRectMake(0, 0, 100, 100);
self.layer.contents = (id)[UIImage imageNamed:@"1"].CGImage;
[self.view.layer addSublayer:self.layer];
// Do any additional setup after loading the view, typically from a nib.
}
-(void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
{
[CATransaction begin];
[CATransaction setAnimationDuration:2.0];
// if (CGRectContainsPoint(self.layer.frame, point)) {
UITouch *touch = [touches anyObject];
CGPoint point = [touch locationInView:self.view];
self.layer.position = point;// }
self.layer.backgroundColor = [self createColor].CGColor;
CGFloat width = arc4random()%100 + 10;
self.layer.frame = CGRectMake(0, 0, width, width);
[CATransaction commit];
}
二，基础动画
CGPoint tapPoint = [tap locationInView:self.view];
//创建基本动画
CABasicAnimation *basicAnimation = [CABasicAnimation animationWithKeyPath:@"position"];
//设置动画的属性
[basicAnimation setDuration:2.0];
CGPoint point = self.layer.position;
/**
*封装point
**/
NSValue *value1 = [NSValue valueWithCGPoint:point];
NSValue *value2 = [NSValue valueWithCGPoint:tapPoint];
basicAnimation.fromValue = value1;//动画的开始点
basicAnimation.toValue = value2;
//将动画添加到相应的层里面
[self.layer addAnimation:basicAnimation forKey:@"position"];
效果如图：
有一个问题，这个动画动完之后就回到初始位置，这一点区别于核心动画
//核心动画修改了层的属性
//基础动画 没有修改层的属性
方法是修改 属性
basicAnimation.removedOnCompletion = NO;
basicAnimation.fillMode = kCAFillModeForward;//动画结束后保持的最后状态
但是，这种方法如果再点击，还是会回到原来的起点变动
所以需要修改属性