IOS 创建透明UIViewController

1创建XIB, UIViewControl

2、重写initWithNibName函数

- (instancetype)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil{

    self = [superinitWithNibName:nibNameOrNilbundle:nibBundleOrNil];

    if (self) {

        self.modalPresentationStyle =UIModalPresentationOverCurrentContext;

    }

    returnself;

}

3、把View 的背影设置为透明。