我有一个使用CAShapeLayer绘制的弧线,我希望它围绕圆圈的中心旋转。我试图在' transform.rotation'上使用CABasicAnimation来获取此动画。属性。但轮换似乎正在发生与圈子中心不同的一点。
-(void)drawRect:(CGRect)rect{
int radius = 100;
CAShapeLayer *circle = [CAShapeLayer layer];
circle.path = [UIBezierPath bezierPathWithRoundedRect:CGRectMake(0, 0, 2.0*radius, 2.0*radius) cornerRadius:radius].CGPath;
circle.fillColor = [UIColor orangeColor].CGColor;
circle.strokeColor = [UIColor blueColor].CGColor;
circle.lineWidth = 5;
circle.strokeStart = 0.0f;
circle.strokeEnd = 0.1f;
[self.layer addSublayer:circle];
CABasicAnimation *spinAnimation = [CABasicAnimation animationWithKeyPath:@"transform.rotation"];
spinAnimation.byValue = [NSNumber numberWithFloat:2.0f*M_PI];
spinAnimation.duration = 4;
spinAnimation.repeatCount = INFINITY;
[circle addAnimation:spinAnimation forKey:@"indeterminateAnimation"];
}
我知道这是一个老问题,但最终会有什么问题。我通过设置图层的边界或锚点来修改很多东西,但它还没有围绕中心旋转。
circle.bounds = self.frame;
以下是我将视图添加到视图控制器的方法。
[self.view addSubview:[[ProgressIndicator alloc] initWithFrame:CGRectMake(50, 50, 200, 200)]];
答案 0 :(得分:5)
这是我最终做的。 错误是将动画添加到子图层而不是图层。 当只需要围绕圆心时需要旋转时,无需修改anchorPoint或位置。
- (id)initWithFrame:(CGRect)frame {
self = [super initWithFrame:frame];
if (self) {
self.backgroundColor = [UIColor clearColor];
int radius = 50;
CAShapeLayer *circle = [CAShapeLayer layer];
circle.path = [UIBezierPath bezierPathWithRoundedRect:CGRectMake(0, 0, 2.0*radius, 2.0*radius) cornerRadius:radius].CGPath;
circle.fillColor = [UIColor clearColor].CGColor;
circle.strokeColor = [UIColor blueColor].CGColor;
circle.lineWidth = 5;
circle.strokeStart = 0.0f;
circle.strokeEnd = 0.1f;
[self.layer addSublayer:circle];
}
return self; }
- (void)drawRect:(CGRect)rect {
CABasicAnimation *spinAnimation = [CABasicAnimation animationWithKeyPath:@"transform.rotation"];
spinAnimation.byValue = [NSNumber numberWithFloat:2.0f*M_PI];
spinAnimation.duration = 4;
spinAnimation.repeatCount = INFINITY;
[self.layer addAnimation:spinAnimation forKey:@"indeterminateAnimation"]; }
答案 1 :(得分:2)
认为最好做这样的事情)
CGFloat center = CGRectGetWidth(frame) / 2;
CGFloat lineWidth = 5;
CGFloat radius = center - lineWidth / 2;
CGRect bounds = frame;
bounds.origin = CGPointZero;
CAShapeLayer *spinLayer = [CAShapeLayer layer];
spinLayer.path = [UIBezierPath bezierPathWithArcCenter:CGPointMake(center, center) radius:radius startAngle:0 endAngle:0.2 clockwise:YES].CGPath;
spinLayer.fillColor = [UIColor clearColor].CGColor;
spinLayer.strokeColor = [UIColor blueColor].CGColor;
spinLayer.lineWidth = 5;
spinLayer.lineCap = kCALineCapRound;
spinLayer.bounds = bounds;
spinLayer.position = CGPointMake(center, center);
[self.layer insertSublayer:spinLayer above:nil];
动画:
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"transform.rotation"];
animation.byValue = [NSNumber numberWithFloat:2.f * M_PI];
animation.duration = 1.5f;
animation.repeatCount = INFINITY;
[spinLayer addAnimation:animation forKey:@"lineRotation"];
[self setNeedsLayout];
Swift 3
var bounds = frame
bounds.origin = CGPoint.zero
let center: CGFloat = frame.size.width
let lineWidth: CGFloat = 5
let radius = center - lineWidth / 2
let spinLayer = CAShapeLayer()
spinLayer.path = UIBezierPath(arcCenter: CGPoint(x: center, y: center),
radius: radius,
startAngle: 0,
endAngle: 0.2,
clockwise: true).cgPath
spinLayer.strokeColor = UIColor.blue.cgColor
spinLayer.fillColor = UIColor.clear.cgColor
spinLayer.lineWidth = lineWidth
spinLayer.lineCap = kCALineCapRound
spinLayer.bounds = bounds
spinLayer.position = CGPoint(x: center, y: center)
view.layer.insertSublayer(spinLayer, above: nil)
let rotation = CABasicAnimation(keyPath: "transform.rotation")
rotation.byValue = NSNumber(value: 2*M_PI as Double)
rotation.duration = 1
rotation.repeatCount = Float.infinity
spinLayer.add(rotation, forKey: "lineRotation")