UIImagePickerController *imagePicker = [[UIImagePickerController alloc] init];
imagePicker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
imagePicker.delegate = self;
imagePicker.navigationBar.translucent = NO;
[_controller presentViewController:imagePicker animated:YES completion:nil];
iOS13系统下 设置了translucent = NO方法还是没效果，最后在自定义navigationController里加了这个好了
[[UINavigationBar appearance] setTranslucent:NO];
