关于CAShapeLayer的一些基本操作

设置圆形进度条:

实现效果如下:

实现代码如下:(注释很详细啦!!!)

 UIView *circleView = [[UIView alloc]initWithFrame:CGRectMake(40, 200, 100, 100)];
    shapeView.backgroundColor = [UIColor greenColor];
    [self.view addSubview:circleView];
    
    // 实现圆形进度条
    
    CAShapeLayer *shapeLayer =[CAShapeLayer layer];
    shapeLayer.frame = circleView.bounds;
    //绘制
    UIBezierPath *path = [UIBezierPath bezierPathWithOvalInRect:circleView.bounds];
    shapeLayer.path = path.CGPath;
    // 设置填充颜色
    shapeLayer.fillColor = [UIColor greenColor].CGColor;
    // 设置线条宽度
    shapeLayer.lineWidth = 2.0f;
    // 设置线条颜色
    shapeLayer.strokeColor = [UIColor redColor].CGColor;
    [circleView.layer addSublayer:shapeLayer];
    
    // 设置基础动画
    CABasicAnimation *pathAnimation = [CABasicAnimation animationWithKeyPath:@"strokeEnd"];
    pathAnimation.duration = 3.0;
    pathAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
    pathAnimation.fromValue = [NSNumber numberWithFloat:0.0f];
    pathAnimation.toValue = [NSNumber numberWithFloat:1.0f];
    pathAnimation.fillMode = kCAFillModeForwards;
    pathAnimation.removedOnCompletion = NO;
    [shapeLayer addAnimation:pathAnimation forKey:@"strokeEndAnimation"];
    

最后记录一个警告的意思和处理方法:

如果出现上面的这警告问题,原因是:

这个往往是复制网上的带格式的代码导致的。

解决办法:

在提示的地方进行换行处理,首先先选中提示的"_".然后按回车键即可。

最好的方法还是自己敲代码比较合适,不复制就不会出现这些警告啦!!!!