ios9 [app setStatusBarHidden:NO] is deprecated

1.「View controller-based status bar appearance」をYESに設定し、

- (BOOL)prefersStatusBarHidden {
    return YES;
}

2. 
「Viewcontroller-based status bar appearance」をNOに設定

    UIApplication *app = [UIApplication sharedApplication];
    app.statusBarStyle = UIStatusBarStyleLightContent;