如何在Xamarin.Forms的NavigationPage.SetTitleView中调用XAML代码？

Question

我有一个Xamarin.Forms应用程序，该应用程序仅针对Android使用自定义导航标题视图。现在，我的标题视图已在我的模板构造函数中定义，如下所示：

[ContentProperty(nameof(InnerContent))]
public partial class ContentCustomTitleView : ContentPage
{

    public static readonly BindableProperty InnerContentProperty = BindableProperty.Create(nameof(InnerContent), typeof(View), typeof(ContentCustomTitleView));
    public static readonly BindableProperty PageTitleProperty = BindableProperty.Create(nameof(PageTitle), typeof(string), typeof(Label), default(string), BindingMode.OneWay);

    public View InnerContent
    {
        get => (View)this.GetValue(InnerContentProperty);
        set => this.SetValue(InnerContentProperty, value);
    }

    public string PageTitle
    {
        get
        {
            var value = (string)GetValue(PageTitleProperty);
            return value;
        }
        set => SetValue(PageTitleProperty, value);
    }

    public ContentCustomTitleView()
    {
        InitializeComponent();
        BindingContext = this;

        if (Device.RuntimePlatform == "Android")
        {
            NavigationPage.SetHasBackButton(this, false);
            NavigationPage.SetTitleView(this, SetBackView());
        }
    }

    StackLayout SetBackView()
    {
        StackLayout backButton = new StackLayout
        {
            Children =
            {
                new Label {
                    Text = "\u25C3",
                    FontSize = 25,
                }
            },
            Padding = new Thickness(5, 0, 20, 0),
            VerticalOptions = LayoutOptions.Center,
            HorizontalOptions = LayoutOptions.Start,
            BackgroundColor = Color.Orange
        };

        var tabEvent = new TapGestureRecognizer();
        tabEvent.Tapped += (object sender, EventArgs e) => { Navigation.PopAsync(); };
        backButton.GestureRecognizers.Add(tabEvent);

        Label pageTitle = new Label()
        {
            FontSize = 14,
            HorizontalTextAlignment = TextAlignment.Center,
            VerticalTextAlignment = TextAlignment.Center,
            VerticalOptions = LayoutOptions.Center,
            HorizontalOptions = LayoutOptions.Center,
        };
        pageTitle.SetBinding(Label.TextProperty, new Binding(path: "PageTitle", source: this));

        StackLayout backView = new StackLayout
        { 
            Children = 
            {
                backButton,
                pageTitle
            },
            VerticalOptions = LayoutOptions.FillAndExpand,
            HorizontalOptions = LayoutOptions.FillAndExpand,
            Orientation = StackOrientation.Horizontal,
        };

        return backView;
    }

}

然后在XAML中使用以下代码：

<t:ContentCustomTitleView xmlns="http://xamarin.com/schemas/2014/forms" 
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"  
             x:Class="MyProject.Details"
             Title="{Binding Title}"
             PageTitle="Application Details">
            <!-- more code here -->
</t:ContentCustomTitleView>

我想做的是在一个单独的xaml文件中创建我的标题视图模板，然后在其中调用该模板NavigationPage.SetTitleView(this, );并将PageTitle属性传递给该标题视图模板。这可能吗？我一直在这个困境中待了好几天。

编辑：

这是我到目前为止所拥有的。在XAML中：

<?xml version="1.0" encoding="UTF-8"?>
<StackLayout xmlns="http://xamarin.com/schemas/2014/forms" 
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml" 
             x:Class="MyProject.TitleViewTemplate"
             VerticalOptions="FillAndExpand" HorizontalOptions="FillAndExpand"
             Orientation="Horizontal">
    <StackLayout x:Name="backButton" Padding="5,0,20,0" VerticalOptions="Start" HorizontalOptions="Start">
        <Label Text="&#x25c3;" FontSize="25"/>
    </StackLayout>
    <Label x:Name="pageTitle" FontSize="14"/>
</StackLayout>

在C＃中：

public partial class TitleViewTemplate : StackLayout
{
   public TitleViewTemplate()
   {
      InitializeComponent();
   }

   public StackLayout SetBackView(EventHandler backButtonClicked)
   {
      var tabEvent = new TapGestureRecognizer();
      tabEvent.Tapped += backButtonClicked;
      backButton.GestureRecognizers.Add(tabEvent);

      pageTitle.SetBinding(Label.TextProperty, new Binding(path: "PageTitle", source: this));

      return this;
   }
}

我想做的就是能够ContentCustomTitleView像这样在我的内部调用它：

// more code here
public ContentCustomTitleView()
{
   InitializeComponent();
   BindingContext = this;
   tv = new TitleViewTemplate();
   if (Device.RuntimePlatform == "Android")
   {
      NavigationPage.SetHasBackButton(this, false);
      NavigationPage.SetTitleView(this, tv.SetBackView(GoBack));
    }
 }
 /// more code here
 void GoBack(object o, EventArgs e) { Navigation.PopAsync() };

这有效，但不是100％。我可以显示XAML，但不能从中获取PageTitle值TitleViewTemplate。有人可以在这里指出我正确的方向吗？也许我缺少一些绑定之类的东西？