棱镜：ViewModelLocator.AutoWireViewModel = QUOT;真"不会不引用的程序工作 [英] prism:ViewModelLocator.AutoWireViewModel="True" will not work for not referenced assemblies

问题描述

我加载我模块的引导程序：

 保护覆盖IModuleCatalog CreateModuleCatalog（）
 {
 VAR moduleCatalog =新DirectoryModuleCatalog（）; \Modules
 moduleCatalog.ModulePath = @; 
返回moduleCatalog; 
} 
  

在模块的项目在壳牌项目中引用工作正常。正确的ViewModels将通过以下附加属性被注入。

<用户控件棱镜：ViewModelLocator.AutoWireViewModel =真[..] LT; />

除非删除了项目引用的ViewModels将不会通过棱镜再设置：ViewModelLocator.AutoWireViewModel =真

有谁知道是什么原因造成的？你可以看该项目的这一行为 https://github.com/mfe- /Get.the.solution.Prism.Demo 。我该如何解决这个问题？

解决方案

基本上，当ViewModelLocationProvider调用 _defaultViewTypeToViewModelTypeResolver ，调用Type.GetType（字符串）返回null。

这可能与负荷一般如何MEF组件。这似乎是与MEF和谷歌搜索将返回了很多类似的问题结果的共同probem。
这是有人用同样的问题：

的 Type.GetType使用MEF 时返回null

您可以尝试在应用程序中的探测路径添​​加插件位置

我个人从来没有使用MEF作为一个DI容器，因为它是一个也没有。 。但是，这是另一天的谈话<​​/ p>

编辑：
其实，我只是想到了一个更好的办法来解决这个问题。只需在您的引导程序像这样覆盖ConfigureViewModelLocator：

 保护覆盖无效ConfigureViewModelLocator（）
 {
群。 ConfigureViewModelLocator（）; 
 
 ViewModelLocationProvider.SetDefaultViewTypeToViewModelTypeResolver（viewType => 
 {
变种的viewName = viewType.FullName;。视图
的viewName = viewName.Replace（。的ViewModels）; 
 VAR viewAssemblyName = viewType.GetTypeInfo（）Assembly.FullName; 
变种后缀= viewName.EndsWith（查看）？的模式。：视图模型; 
 VAR viewModelName =的String.Format（CultureInfo.InvariantCulture，{0} {1}的viewName，后缀）; 
 
 VAR总成= viewType.GetTypeInfo（）大会; 
型变种= assembly.GetType（viewModelName，真）; 
 
返回类型; 
}）; 
} 
  

这样我们就可以直接问组装的类型，而不是试图让该框架算起来我们。

I load my modules in the bootstrapper with:

    protected override IModuleCatalog CreateModuleCatalog()
    {
        var moduleCatalog = new DirectoryModuleCatalog();
        moduleCatalog.ModulePath = @".\Modules";
        return moduleCatalog;
    }

which works fine when the project of the modules are referenced in the shell project. The correct ViewModels will be injected by the following attached property.

<UserControl prism:ViewModelLocator.AutoWireViewModel="True" [..]</>

Unless I remove the project reference the ViewModels will not be set anymore by the prism:ViewModelLocator.AutoWireViewModel="True".

Does anybody know the what causes that? You can watch this behaviour on the project https://github.com/mfe-/Get.the.solution.Prism.Demo . How can I fix this?

解决方案

Basically, when the ViewModelLocationProvider calls the _defaultViewTypeToViewModelTypeResolver, the call to Type.GetType(string) returns null.

This might be related to how MEF loads assemblies in general. This seems to be a common probem with MEF and a Google search will return a lot of results with similar issues. Here is someone with the same problem:

Type.GetType returns null when using MEF

You could try adding the plugin location in the probing path of the application.

I personally never use MEF as a DI container, because it's not one. But that is a conversation for another day.

EDIT: Actually, I just thought of a better way to get around this. Simply override ConfigureViewModelLocator in your bootstrapper like this:

        protected override void ConfigureViewModelLocator()
    {
        base.ConfigureViewModelLocator();

        ViewModelLocationProvider.SetDefaultViewTypeToViewModelTypeResolver(viewType =>
        {
            var viewName = viewType.FullName;
            viewName = viewName.Replace(".Views.", ".ViewModels.");
            var viewAssemblyName = viewType.GetTypeInfo().Assembly.FullName;
            var suffix = viewName.EndsWith("View") ? "Model" : "ViewModel";
            var viewModelName = String.Format(CultureInfo.InvariantCulture, "{0}{1}", viewName, suffix);

            var assembly = viewType.GetTypeInfo().Assembly;
            var type = assembly.GetType(viewModelName, true);

            return type;
        });
    }

This way we can ask the assembly for the type directly and not try to have the framework figure it out for us.

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