Xamarin.Forms iOS显示“主要”和“详细信息”，而不仅仅是后退图标或菜单图标

// 创建一个NavigationPage
var navigationPage = new NavigationPage(new MainPage());

// 在MainPage中添加一个按钮，点击按钮后导航到DetailPage
var button = new Button { Text = "显示详细信息" };
button.Clicked += async (sender, args) =>
{
    await navigationPage.PushAsync(new DetailPage());
};

// 在MainPage的构造函数中添加按钮到页面上
public MainPage()
{
    Content = new StackLayout
    {
        Children = { button }
    };
}

// 在DetailPage中添加一个按钮，点击按钮后返回到上一个页面
var backButton = new Button { Text = "返回" };
backButton.Clicked += async (sender, args) =>
{
    await navigationPage.PopAsync();
};

// 在DetailPage的构造函数中添加按钮到页面上
public DetailPage()
{
    Content = new StackLayout
    {
        Children = { backButton }
    };
}