Defaults to UIModalPresentationAutomatic on iOS starting in iOS 13.0, and UIModalPresentationFullScreen on previous versions. Defaults to UIModalPresentationFullScreen on all other platforms.
IOS13以前控制器UIModalPresentationStyle默认是UIModalPresentationFullScreen,
而IOS13控制器UIModalPresentationStyle默认是UIModalPresentationAutomatic（卡片样式）,
因此IOS13模态跳转的界面会以卡片的样式展示；
解决办法：
UIViewController *vc = [[UIViewController alloc] init];
[vc setModalPresentationStyle:UIModalPresentationFullScreen];
[self presentViewController:vc animated:YES completion:nil];
