为CAShapeLayer设置动画以绘制进度圆

Question

我想画一个用来表示进展的圆圈.进度更新可能会很快进行,我想对圆圈的更改进行动画处理.

我已尝试使用以下方法执行此操作,但似乎没有任何工作.这可能吗？

- (id)initWithFrame:(CGRect)frame strokeWidth:(CGFloat)strokeWidth insets:(UIEdgeInsets)insets
{
    if (self = [super initWithFrame:frame])
    {

        self.strokeWidth = strokeWidth;

        CGPoint arcCenter = CGPointMake(CGRectGetMidX(self.bounds), CGRectGetMidY(self.bounds));
        CGFloat radius = CGRectGetMidX(self.bounds) - insets.top - insets.bottom;

        self.circlePath = [UIBezierPath bezierPathWithArcCenter:arcCenter
                                                         radius:radius
                                                     startAngle:M_PI
                                                       endAngle:-M_PI
                                                      clockwise:YES];
        [self addLayer];
    }
    return self;
}


- (void)setProgress:(double)progress {
    _progress = progress;
    [self updateAnimations];
}

- (void)addLayer {

    CAShapeLayer *progressLayer = [CAShapeLayer layer];
    progressLayer.path = self.circlePath.CGPath;
    progressLayer.strokeColor = [[UIColor whiteColor] CGColor];
    progressLayer.fillColor = [[UIColor clearColor] CGColor];
    progressLayer.lineWidth = self.strokeWidth;
    progressLayer.strokeStart = 10.0f;
    progressLayer.strokeEnd = 40.0f;

    [self.layer addSublayer:progressLayer];
    self.currentProgressLayer = progressLayer;

}

- (void)updateAnimations{

    self.currentProgressLayer.strokeEnd = self.progress;
    [self.currentProgressLayer didChangeValueForKey:@"endValue"];
}

目前,该代码甚至不画了圈,但在取出progressLayer的strokeStart并且strokeEnd将绘制完整的圆.

如何让它从某个点开始并根据我设置我的progress属性开始绘制圆圈？

Answer 1

我想到了.该strokeStart和strokeEnd值从0.0到1.0,所以我给它的值是太高.

所以,我刚刚将我的设置更新为:

- (void)setProgress:(double)progress {
    _progress = progress * 0.00460;
    [self updateAnimations];
}