xamarin.forms如何在标题栏中显示视图

// 创建自定义导航栏
public class CustomNavigationPage : NavigationPage
{
    public CustomNavigationPage(Page root) : base(root)
    {
        // 设置导航栏样式
        BarBackgroundColor = Color.Blue;
        BarTextColor = Color.White;

        // 创建自定义视图
        var customView = new Label
        {
            Text = "自定义视图",
            HorizontalOptions = LayoutOptions.Center,
            VerticalOptions = LayoutOptions.Center
        };

        // 将自定义视图添加到导航栏
        var stackLayout = new StackLayout();
        stackLayout.Children.Add(customView);
        TitleView = stackLayout;
    }
}

// 在应用程序的入口点设置自定义导航栏为主导航栏
public partial class App : Application
{
    public App()
    {
        InitializeComponent();

        MainPage = new CustomNavigationPage(new MainPage());
    }
}