####自用
@property (strong, nonatomic) UIColor * strokeColor;
@property (assign, nonatomic) CGFloat percent;
@property (assign, nonatomic) CFTimeInterval duration;
- (void)show;
调用
CZPieChatView * view = [[CZPieChatView alloc]initWithFrame:CGRectMake(100, 100, 100, 100)];
view.strokeColor = [UIColor grayColor];
view.duration = 0.8;
view.percent = 0.75;
[view show];
[self.view addSubview:view];