通过依赖注入进行多重导航控制 [英] Multiple navigation control through dependency injection

问题描述

我的基本内容类.我将此类用作我的项目的主题.我不知道此信息是否相关.在这里，我创建一个抽象方法，该方法将使导航方法超载.

My base content class. I used this class as a theme for my project. I do not know this info relevant or not. In here I create an abstract method that would overload the navigation method.

public abstract class BaseContentPage : ContentPage
{
    public readonly BaseViewModel BaseViewModel;

    public BaseContentPage(BaseViewModel baseViewModel)
    {
        BaseViewModel = baseViewModel;
    }

    public abstract void Navigate(SelectedItemChangedEventArgs e);
}

在我的依赖项中构建依赖项注入公共类的Locator.此类中的重点是将此类添加到容器中以进行所有代码丢失耦合

In my locator where I build the dependency Injection public class Locator. in this class mainly focus on adding this class to the container to make the all code loss coupling

    private readonly ContainerBuilder _builder;

    public Locator()
    {
        _builder = new ContainerBuilder();
        RegisterTypes();
        Container = _builder.Build();
    }

    public IContainer Container { get; set; }

    private void RegisterTypes()
    {
        _builder.RegisterType<WardListService>().As<IWardListService>();
        _builder.RegisterType<WardListPageViewModel>();
        _builder.RegisterType<WardListPage>();

        _builder.RegisterType<PatientService>().As<IPatientService>();
        _builder.RegisterType<PatientListPageViewModel>();
        _builder.RegisterType<PatientListViewPage>();

        _builder.RegisterType<PatientDetailsPageViewModel>();
        _builder.RegisterType<PatientDetailsViewPage>();   }

在我的 app.Xaml.Cs 文件中

 public App()
    {
        InitializeComponent();              
        Locator locator = new Locator();
        Container = locator.Container;
        MainPage = new NavigationPage(Container.Resolve<WardListPage>());
    }

    public static IContainer Container;

我在页面后面的视图代码中使用了这种方法进行导航

I used this method for navigation in my view code behind page

    public async override void Navigate(SelectedItemChangedEventArgs e)
    {
        PatientDetailsViewPage patientDetailsViewPage = App.Container.Resolve<PatientDetailsViewPage>();
        patientDetailsViewPage.BaseViewModel.SelectedPatient = e.SelectedItem as PatientViewModel;
        await Navigation.PushAsync(patientDetailsViewPage);
    }

此代码运行良好，但只能导航到一页.例如，在一页上，我们有两个按钮可导航到两个不同的页面.我不知道如何使用上面的导航重载程序来实现此任务.任何人都可以提出解决该问题的建议?另外，我使用autofac进行依赖注入谢谢

This code is working perfectly but this only can navigate to one page.meaning as an example on one page we have two buttons that navigate to two different pages. I don't know how to implement this task using above navigate overloader. How to do it can anyone give suggestion to overcome the problem?. Also, I used autofac for dependency injection Thank you

推荐答案

您可以在CustomNavigationPage中定义容器，并在每个导航页面实例中使用.

You can define container in your CustomNavigationPage and use in every navigation page instance.

public class CustomNavigationPage : NavigationPage
{
   public static IContainer Container;

   public CustomNavigationPage()
   {
       Locator locator = new Locator();
       locator.RegisterTypes();
       Container = locator.Container();
   }
}

我所说的是伪代码.

您创建了自定义的导航页面.因此，您可以使用这种方式浏览页面，例如:

You creating a navigation page that customized. So you can use this navigating your pages for example:

CustomNavigationPage.PushASync(new TestPage(Container.Resolve<WardListPage>())):

如果使用此选项，则您的自定义导航页面将在每次调用时解决您的依赖性.

If use this your custom navigation page will be resolve your dependencies every call.

要提高性能，您可以使用以下方式注册您的依赖项: 单例模式.应用启动时，将注册依赖项. 使用此注册的依赖项之后.

To improve performance you can register your dependencies with singleton pattern. When the app started, dependencies will be registered. After you use this registered dependencies.

有一个改进:您可以使用单例模式定义一个静态定位器，它将静态依赖项注册到app.cs中.

There is an improvement : You define a static locator with singleton pattern it registers dependencies in app.cs

public sealed class Locator
    {
    private static Locator locator = null;
    private static readonly object padlock = new object();

    Locator()
    {
      //your registries
    }

    public static Locator Locator
    {
    get
    {
    lock (padlock)
    {
    if (locator == null)
    {
    locator = new Locator();
    }
    return locator;
    }
    }
    }
    }

还有您的app.cs:

And your app.cs :

 public App()
    {
        InitializeComponent();              
        Locator locator = new Locator();
        Container = locator.Container;
        .
        .
    }

    public static IContainer Container;

这样，您只需一次注册您的依赖项.没有重复的代码.将仅使用一个实例.

This way you only one time register your dependencies. There is no duplication of code. Only one instance will be used.

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