在Layer层做圆形进度条

初始化

继承CAShapeLayer

    self.progressLayer = [CAShapeLayer layer];
    self.progressLayer.path = [self drawPathWithArcCenter];
    self.progressLayer.fillColor = [UIColor clearColor].CGColor;
    self.progressLayer.strokeColor = RGB(247, 77, 211).CGColor;
    self.progressLayer.lineWidth = 26;
    self.progressLayer.lineCap = kCALineCapRound;
    self.progressLayer.lineJoin = kCALineJoinRound;
    [self addSublayer:self.progressLayer];

UIBezierPath

- (CGPathRef)drawPathWithArcCenter {
    
    CGFloat position_y = self.frame.size.height/2;
    CGFloat position_x = self.frame.size.width/2;
    return [UIBezierPath bezierPathWithArcCenter:CGPointMake(position_x, position_y)
                                          radius:position_y
                                      startAngle:(-M_PI/2)
                                        endAngle:(3*M_PI/2)
                                       clockwise:YES].CGPath;
}

启动

- (void)startAnimation {
    
    CABasicAnimation *pathAnimation = [CABasicAnimation animationWithKeyPath:@"strokeEnd"];
    pathAnimation.duration = 1.0;
    pathAnimation.fromValue = @(0);
    pathAnimation.toValue = @(self.percent);
    pathAnimation.removedOnCompletion = YES;
    
    [self.progressLayer addAnimation:pathAnimation forKey:nil];
}