状态栏样式修改

说明：只是局部修改方案

1. 修改info.plist
   View controller-based status bar appearance ： YES

2. 重写preferredStatusBarStyle 方法

• (UIStatusBarStyle)preferredStatusBarStyle {
  if (self.scrollview.contentOffset.y > 0) {
  return UIStatusBarStyleDefault;
  }
  return UIStatusBarStyleLightContent;
  }

3. 在需要修改的地方增加下面方法
   [self setNeedsStatusBarAppearanceUpdate];

补充：
//设置状态栏背景颜色

• (void)setStatusBarBackgroundColor:(UIColor *)color {
  if (@available(iOS 13.0, *)) {
  UIView *statusBar = [[UIView alloc]initWithFrame:[UIApplication sharedApplication].keyWindow.windowScene.statusBarManager.statusBarFrame];

       statusBar.backgroundColor = color;
       [[UIApplication sharedApplication].keyWindow addSubview:statusBar];
   } else {
       // Fallback on earlier versions
       UIView *statusBar = [[[UIApplication sharedApplication] valueForKey:@"statusBarWindow"] valueForKey:@"statusBar"];
          if ([statusBar respondsToSelector:@selector(setBackgroundColor:)]) {
              statusBar.backgroundColor = color;
          }
   }
  

}