iOS开篇——UI之UIActivityIndicatorView（菊花）

    UIActivityIndicatorView * AIV = [[UIActivityIndicatorView alloc]initWithFrame:CGRectMake(50, 50, 50, 50)];
    
    //设置样式
    AIV.activityIndicatorViewStyle = UIActivityIndicatorViewStyleGray;
    /*
     typedef NS_ENUM(NSInteger, UIActivityIndicatorViewStyle) {
     UIActivityIndicatorViewStyleWhiteLarge,
     UIActivityIndicatorViewStyleWhite,
     UIActivityIndicatorViewStyleGray __TVOS_PROHIBITED,
     };
     */
    AIV.color = [UIColor redColor];
    
    //缩放倍数
    AIV.transform = CGAffineTransformMakeScale(2, 2) ;

[AIV startAnimating];
//菊花停止旋转
[AIV stopAnimating];

    [[UIApplication sharedApplication]setNetworkActivityIndicatorVisible:YES];