iOS 實作類別似雷達效果的核心代碼

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 1 -(void)drawRect:(CGRect)rect 2 { 3     [[UIColor clearColor]setFill]; 4     UIRectFill(rect); 5     NSInteger pulsingCount = 3; 6     double animationDuration = 2; 7      8     CALayer * animationLayer = [[CALayer alloc]init]; 9     self.animationLayer = animationLayer;10     11     for (int i = 0; i < pulsingCount; i++) {12         CALayer * pulsingLayer = [[CALayer alloc]init];13         pulsingLayer.frame = CGRectMake(0, 0, rect.size.width, rect.size.height);14         pulsingLayer.backgroundColor = [UIColor colorWithRed:92.0/255.0 green:181.0/255.0 blue:217.0/255.0 alpha:1.0].CGColor;15         pulsingLayer.borderColor = [UIColor colorWithRed:92.0/255.0 green:181.0/255.0 blue:217.0/255.0 alpha:1.0].CGColor;16         pulsingLayer.borderWidth = 1.0;17         pulsingLayer.cornerRadius = rect.size.height/2;18         19         CAMediaTimingFunction * defaultCurve = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear];20         21         CAAnimationGroup * animationGroup = [[CAAnimationGroup alloc]init];22         animationGroup.fillMode = kCAFillModeBoth;23         animationGroup.beginTime = CACurrentMediaTime() + (double)i * animationDuration/(double)pulsingCount;24         animationGroup.duration = animationDuration;        animationGroup.repeatCount = HUGE_VAL;25         animationGroup.timingFunction = defaultCurve;26         27         CABasicAnimation * scaleAnimation = [CABasicAnimation animationWithKeyPath:@"transform.scale"];28         scaleAnimation.autoreverses = NO;29         scaleAnimation.fromValue = [NSNumber numberWithDouble:0.2];30         scaleAnimation.toValue = [NSNumber numberWithDouble:1.0];31         32         CAKeyframeAnimation * opacityAnimation = [CAKeyframeAnimation animationWithKeyPath:@"opacity"];33         opacityAnimation.values = @[[NSNumber numberWithDouble:1.0],[NSNumber numberWithDouble:0.5],[NSNumber numberWithDouble:0.3],[NSNumber numberWithDouble:0.0]];34         opacityAnimation.keyTimes = @[[NSNumber numberWithDouble:0.0],[NSNumber numberWithDouble:0.25],[NSNumber numberWithDouble:0.5],[NSNumber numberWithDouble:1.0]];35         animationGroup.animations = @[scaleAnimation,opacityAnimation];36         37         [pulsingLayer addAnimation:animationGroup forKey:@"pulsing"];38         [animationLayer addSublayer:pulsingLayer];39     }40     self.animationLayer.zPosition = -1;//重新載入時，使動畫至底層41     [self.layer addSublayer:self.animationLayer];42     43     CALayer * thumbnailLayer = [[CALayer alloc]init];44     thumbnailLayer.backgroundColor = [UIColor whiteColor].CGColor;45     CGRect thumbnailRect = CGRectMake(0, 0, 46, 46);46     thumbnailRect.origin.x = (rect.size.width - thumbnailRect.size.width)/2.0;47     thumbnailRect.origin.y = (rect.size.height - thumbnailRect.size.height)/2.0;48     thumbnailLayer.frame = thumbnailRect;49     thumbnailLayer.cornerRadius = 23.0;50     thumbnailLayer.borderWidth = 1.0;51     thumbnailLayer.masksToBounds = YES;52     thumbnailLayer.borderColor = [UIColor whiteColor].CGColor;53     UIImage * thumbnail = self.thumbnailImage;54     thumbnailLayer.contents = (id)thumbnail.CGImage;55     thumbnailLayer.zPosition = -1;56     [self.layer addSublayer:thumbnailLayer];57 }

iOS 實作類別似雷達效果的核心代碼