解决方案:
在 info.plist 文件中添加字段View controller-based status bar appearance:设置为 NO
然后设置[UIApplication sharedApplication].statusBarHidden = YES;
View controller-based status bar appearance:
如果在 plist 文件中设置该字段为 yes,或者不添加该字段,则 view Controller 设置的优先级高于 Application,如果设置为 NO,则 Application 设置的优先级高于 view Controller。