正在编写代码以创建Arc。
UIBezierPath *firstCircle = [UIBezierPath bezierPath];
[firstCircle addArcWithCenter:CGPointMake(0, 500) radius:150 startAngle:90 endAngle:180 clockwise:NO];
firstCircle.lineWidth = 100;
[firstCircle closePath];
[[UIColor blackColor]setStroke];
[firstCircle stroke];
我如何设置此弧的动画?