Wpf 我可以实现自己的视图解析服务并让RequestNavigate使用它吗？

我对Prism还比较陌生，目前正在使用Prism作为概念验证项目重新编写一个现有的应用程序

该应用程序使用MVVM和ViewModel-first方法：我们的ViewModel由容器解析，而

IViewResolver

服务会确定它应该连接到哪个视图（使用名称约定等）

目前的代码（向选项卡控件添加视图）如下所示：

var vm = (get ViewModel from somewhere)
IRegion reg = _regionManager.Regions["MainRegion"];
var vw = _viewResolver.FromViewModel(vm); // Spins up a view and sets its DataContext
reg.Add(vw);
reg.Activate(vw);

_regionManager.RequestNavigate(
    "MainRegion", 
    new Uri("NameOfMyViewModel", UriKind.Relative)
);

public class ViewModelContentLoader : RegionNavigationContentLoader
{
    private readonly IServiceLocator serviceLocator;

    public ViewModelContentLoader(IServiceLocator serviceLocator)
        : base(serviceLocator)
    {
        this.serviceLocator = serviceLocator;
    }

    // THIS IS CALLED WHEN A NEW VIEW NEEDS TO BE CREATED
    // TO SATISFY A NAVIGATION REQUEST
    protected override object CreateNewRegionItem(string candidateTargetContract)
    {
        // candidateTargetContract is e.g. "NameOfMyViewModel"

        // Just a suggestion, plug in your own resolution code as you see fit
        var viewModelType = this.GetTypeFromName(candidateTargetContract);
        var viewModel = this.serviceLocator.GetInstance(viewModelType);

        // get ref to viewResolver somehow -- perhaps from the container?
        var view = _viewResolver.FromViewModel(vm);

        return view;
    }

    // THIS IS CALLED TO DETERMINE IF THERE IS ANY EXISTING VIEW
    // THAT CAN SATISFY A NAVIGATION REQUEST
    protected override IEnumerable<object> 
    GetCandidatesFromRegion(IRegion region, string candidateNavigationContract)
    {
        if (region == null) {
            throw new ArgumentNullException("region");
        }

        // Just a suggestion, plug in your own resolution code as you see fit
        var viewModelType = this.GetTypeFromName(candidateNavigationContract);

        return region.Views.Where(v =>
            ViewHasDataContract((FrameworkElement)v, viewModelType) ||
            string.Equals(v.GetType().Name, candidateNavigationContract, StringComparison.Ordinal) ||
            string.Equals(v.GetType().FullName, candidateNavigationContract, StringComparison.Ordinal));
    }

    // USED IN MY IMPLEMENTATION OF GetCandidatesFromRegion
    private static bool 
    ViewHasDataContract(FrameworkElement view, Type viewModelType)
    {
        var dataContextType = view.DataContext.GetType();

        return viewModelType.IsInterface
           ? dataContextType.Implements(viewModelType)
           : dataContextType == viewModelType 
                   || dataContextType.GetAncestors().Any(t => t == viewModelType);
    }

    // USED TO MAP STRINGS OF VIEWMODEL TYPE NAMES TO ACTUAL TYPES
    private Type GetTypeFromName(string typeName)
    {
        // here you need to map the string type to a Type object, e.g.
        // "NameOfMyViewModel" => typeof(NameOfMyViewModel)

        return typeof(NameOfMyViewModel); // hardcoded for simplicity
    }
}

这一切都很好，但是我真的很想使用Prism导航框架来为我做这些事情，这样我就可以做这样的事情：

var vm = (get ViewModel from somewhere)
IRegion reg = _regionManager.Regions["MainRegion"];
var vw = _viewResolver.FromViewModel(vm); // Spins up a view and sets its DataContext
reg.Add(vw);
reg.Activate(vw);

_regionManager.RequestNavigate(
    "MainRegion", 
    new Uri("NameOfMyViewModel", UriKind.Relative)
);

public class ViewModelContentLoader : RegionNavigationContentLoader
{
    private readonly IServiceLocator serviceLocator;

    public ViewModelContentLoader(IServiceLocator serviceLocator)
        : base(serviceLocator)
    {
        this.serviceLocator = serviceLocator;
    }

    // THIS IS CALLED WHEN A NEW VIEW NEEDS TO BE CREATED
    // TO SATISFY A NAVIGATION REQUEST
    protected override object CreateNewRegionItem(string candidateTargetContract)
    {
        // candidateTargetContract is e.g. "NameOfMyViewModel"

        // Just a suggestion, plug in your own resolution code as you see fit
        var viewModelType = this.GetTypeFromName(candidateTargetContract);
        var viewModel = this.serviceLocator.GetInstance(viewModelType);

        // get ref to viewResolver somehow -- perhaps from the container?
        var view = _viewResolver.FromViewModel(vm);

        return view;
    }

    // THIS IS CALLED TO DETERMINE IF THERE IS ANY EXISTING VIEW
    // THAT CAN SATISFY A NAVIGATION REQUEST
    protected override IEnumerable<object> 
    GetCandidatesFromRegion(IRegion region, string candidateNavigationContract)
    {
        if (region == null) {
            throw new ArgumentNullException("region");
        }

        // Just a suggestion, plug in your own resolution code as you see fit
        var viewModelType = this.GetTypeFromName(candidateNavigationContract);

        return region.Views.Where(v =>
            ViewHasDataContract((FrameworkElement)v, viewModelType) ||
            string.Equals(v.GetType().Name, candidateNavigationContract, StringComparison.Ordinal) ||
            string.Equals(v.GetType().FullName, candidateNavigationContract, StringComparison.Ordinal));
    }

    // USED IN MY IMPLEMENTATION OF GetCandidatesFromRegion
    private static bool 
    ViewHasDataContract(FrameworkElement view, Type viewModelType)
    {
        var dataContextType = view.DataContext.GetType();

        return viewModelType.IsInterface
           ? dataContextType.Implements(viewModelType)
           : dataContextType == viewModelType 
                   || dataContextType.GetAncestors().Any(t => t == viewModelType);
    }

    // USED TO MAP STRINGS OF VIEWMODEL TYPE NAMES TO ACTUAL TYPES
    private Type GetTypeFromName(string typeName)
    {
        // here you need to map the string type to a Type object, e.g.
        // "NameOfMyViewModel" => typeof(NameOfMyViewModel)

        return typeof(NameOfMyViewModel); // hardcoded for simplicity
    }
}

让Prism旋转ViewModel+视图，设置DataContext并将视图插入区域

通过创建引用ViewModel类型的数据模板，我取得了一些成功，例如：

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:Module01">
<DataTemplate DataType="{x:Type local:TestViewModel}">
<local:TestView />
</DataTemplate>
</ResourceDictionary>

…并在初始化模块时让模块将相关的资源字典添加到应用程序资源中，但这似乎有点垃圾

是否有一种方法可以有效地从Prism接管视图创建，以便在调用

RequestNavigate

时，我可以查看提供的

Uri

，并在此基础上旋转视图/视图模型？RegionManager.RegisterViewWithRegion中有一个重载，它接受一个委托，允许您自己提供一个视图，我想我想要这样的东西

我想我可能需要提供我自己的

IRegionBehaviorFactory

，但我不确定涉及到什么（或者即使我走的是正确的道路！）

感谢您的帮助

--

---

注：最初发布在

上，以避免对“视图模型优先方法”的混淆： 您更多地使用“控制器方法”，而不是“视图模型优先方法”。“ViewModel优先方法”是，当您将视图注入ViewModel中，但通过第三方组件（控制器）将ViewModel和视图连接起来时，顺便问一下，（我不想说“最佳”，但）最松散耦合的方法是什么

但要回答你的问题： 一个可能的解决方案是为Prism RegionManager编写一个扩展，它完全按照您上面所描述的那样执行：

public静态类regionmanager
{            
公共静态无效添加区域(
此IRegionManager区域管理器，字符串区域）
{
var viewModel=ServiceLocator.Current.GetInstance（）；
框架元素视图；
//根据您的约定获取视图
if（view==null）抛出新的NullReferenceException（“未找到视图”）；
view.DataContext=viewModel；
regionManager.AddToRegion（区域，视图）；
regionManager.Regions[区域].激活（视图）；
}
}

然后您可以这样调用此方法：

var vm = (get ViewModel from somewhere)
IRegion reg = _regionManager.Regions["MainRegion"];
var vw = _viewResolver.FromViewModel(vm); // Spins up a view and sets its DataContext
reg.Add(vw);
reg.Activate(vw);

_regionManager.RequestNavigate(
    "MainRegion", 
    new Uri("NameOfMyViewModel", UriKind.Relative)
);

public class ViewModelContentLoader : RegionNavigationContentLoader
{
    private readonly IServiceLocator serviceLocator;

    public ViewModelContentLoader(IServiceLocator serviceLocator)
        : base(serviceLocator)
    {
        this.serviceLocator = serviceLocator;
    }

    // THIS IS CALLED WHEN A NEW VIEW NEEDS TO BE CREATED
    // TO SATISFY A NAVIGATION REQUEST
    protected override object CreateNewRegionItem(string candidateTargetContract)
    {
        // candidateTargetContract is e.g. "NameOfMyViewModel"

        // Just a suggestion, plug in your own resolution code as you see fit
        var viewModelType = this.GetTypeFromName(candidateTargetContract);
        var viewModel = this.serviceLocator.GetInstance(viewModelType);

        // get ref to viewResolver somehow -- perhaps from the container?
        var view = _viewResolver.FromViewModel(vm);

        return view;
    }

    // THIS IS CALLED TO DETERMINE IF THERE IS ANY EXISTING VIEW
    // THAT CAN SATISFY A NAVIGATION REQUEST
    protected override IEnumerable<object> 
    GetCandidatesFromRegion(IRegion region, string candidateNavigationContract)
    {
        if (region == null) {
            throw new ArgumentNullException("region");
        }

        // Just a suggestion, plug in your own resolution code as you see fit
        var viewModelType = this.GetTypeFromName(candidateNavigationContract);

        return region.Views.Where(v =>
            ViewHasDataContract((FrameworkElement)v, viewModelType) ||
            string.Equals(v.GetType().Name, candidateNavigationContract, StringComparison.Ordinal) ||
            string.Equals(v.GetType().FullName, candidateNavigationContract, StringComparison.Ordinal));
    }

    // USED IN MY IMPLEMENTATION OF GetCandidatesFromRegion
    private static bool 
    ViewHasDataContract(FrameworkElement view, Type viewModelType)
    {
        var dataContextType = view.DataContext.GetType();

        return viewModelType.IsInterface
           ? dataContextType.Implements(viewModelType)
           : dataContextType == viewModelType 
                   || dataContextType.GetAncestors().Any(t => t == viewModelType);
    }

    // USED TO MAP STRINGS OF VIEWMODEL TYPE NAMES TO ACTUAL TYPES
    private Type GetTypeFromName(string typeName)
    {
        // here you need to map the string type to a Type object, e.g.
        // "NameOfMyViewModel" => typeof(NameOfMyViewModel)

        return typeof(NameOfMyViewModel); // hardcoded for simplicity
    }
}

regionManager.AddToRegion（“MyRegion”）；

你一定能做到。我发现Prism v4确实是可扩展的，只要您知道在哪里插入

在这种情况下，您需要自己的自定义实现

下面是如何在引导程序中进行设置（示例来自我自己的一个项目中的

UnityBootstrapper

的子类）：

---

这不正是我在最初的示例中所做的吗我所追求的是一种覆盖/影响导航api（即RequestNavigate（））如何从URI解析视图实例的方法。我对这个问题进行了略微编辑，希望能让它更清楚！那真是太完美了！谢谢Pj