1、tabbar相关

UITabBarAppearance *appearance = [[UITabBarAppearance alloc] init];

//tabBaritem title选中状态颜色

appearance.stackedLayoutAppearance.selected.titleTextAttributes = @{

   NSForegroundColorAttributeName:[UIColor blueColor],

};

//tabBaritem title未选中状态颜色

appearance.stackedLayoutAppearance.normal.titleTextAttributes = @{

   NSForegroundColorAttributeName:[UIColor blueColor],

};

//tabBar背景颜色

appearance.backgroundColor = [UIColor blackColor];

self.tabBarItem.scrollEdgeAppearance = appearance;

self.tabBarItem.standardAppearance = appearance;

2、navigationBar相关

UINavigationBarAppearance *appearance = [[UINavigationBarAppearance alloc] init];

appearance.backgroundColor = [UIColor blackColor];

self.navigationBar.standardAppearance = appearance;

self.navigationBar.scrollEdgeAppearance = appearance;

3、tableView相关

为了配合以前的开发习惯，我们只需要在创建实例的时候进行对间距的设置即可

if (@available(iOS 15.0, *)) {

    tableView.sectionHeaderTopPadding = 0;

}

或者全局设置

if (@available(iOS 15.0, *)) {

    [UITableView appearance].sectionHeaderTopPadding = 0;

}