iOS实现带动画的环形进度条

完成后在要调用的控制器里，仅需几段代码：传进的参数：为0-1

 LoopProgressView *custom = [[LoopProgressView alloc]initWithFrame:CGRectMake(50, 100, 100, 100)];
 custom.progress = 0.44;
 [self.view addSubview:custom];