修改状态栏以及navgationController标题颜色

1、info.plist文件中添加字段：View controller-based status bar appearance ——————> NO2、设置状态栏字体    [[UIApplication sharedApplication] setStatusBarStyle:UIStatusBarStyleLightContent];    [viewcontroller setNeedsStatusBarAppearanceUpdate];3、改变nav的title的字体颜色    NSDictionary * dict = [NSDictionary dictionaryWithObject:[UIColor whiteColor] forKey:NSForegroundColorAttributeName];    navigationcontroller.navigationBar.titleTextAttributes = dict;