我有一个简单的WPF应用程序，我想开始。我下面的Microsoft模式与实践复合应用程序指南WPF。然而，我的WPF应用程序与TypeInitializationException立即失败，我跟着他们的指示。

I have a simple WPF application which I am trying to start. I am following the Microsoft Patterns and Practices "Composite Application Guidance for WPF". I've followed their instructions however my WPF application fails immediately with a "TypeInitializationException".

InnerException属性显示，的类型初始System.Windows.Navigation.BaseUriHelper'引发了异常。

The InnerException property reveals that "The type initializer for 'System.Windows.Navigation.BaseUriHelper' threw an exception."

下面是我的App.xaml：

Here is my app.xaml:

<Application x:Class="MyNamespace.App"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
    <Application.Resources>         
    </Application.Resources>
</Application>

和这里是我的app.xaml.cs（抛出的异常的公共应用程序（））：

And here is my app.xaml.cs (exception thrown at "public App()"):

public partial class App : Application
{
    public App()
    {
        Bootstrapper bootStrapper = new Bootstrapper();
        bootStrapper.Run();
    }
}

我已经设置了应用程序类项目的启动对象。

I have set the "App" class as the startup object in the project.

什么是误入歧途？

推荐答案

感谢@ IMA ，你的答案我指出了正确的方向。我使用一个app.config文件，它包含这样的：

Thanks @ima, your answer pointed me in the right direction. I was using an app.config file and it contained this:

<configuration>
  <startup>
    <supportedRuntime version="v2.0.50727" sku="Client"/>
  </startup>
  <configSections>
    <section name="modules" type="Microsoft.Practices.Composite.Modularity.ModulesConfigurationSection, Microsoft.Practices.Composite"/>
  </configSections>
  <modules>
    <module assemblyFile="Modules/MyNamespace.Modules.ModuleName.dll" moduleType="MyNamespace.Modules.ModuleName.ModuleClass" moduleName="Name"/>
  </modules>
</configuration>

看来问题是在＆lt;启动＆GT;元素，因为当我删除它的应用程序运行得很好。我很困惑，因为Visual Studio 2008中补充说，当我检查，利用客户端配置文件可以在3.5 SP1中的框。

It seems the problem was the <startup> element because when I removed it the application ran fine. I was confused because Visual Studio 2008 added that when I checked the box to utilise the "Client Profile" available in 3.5 SP1.

经过一番瞎检查和取消选中我结束了这样的一个配置文件的邮箱：

After some mucking about checking and un-checking the box I ended up with a configuration file like this:

<configuration>
  <configSections>
    <section name="modules" type="Microsoft.Practices.Composite.Modularity.ModulesConfigurationSection, Microsoft.Practices.Composite"/>
  </configSections>
  <modules>
    <module assemblyFile="Modules/MyNamespace.Modules.ModuleName.dll" moduleType="MyNamespace.Modules.ModuleName.ModuleClass" moduleName="Name"/>
  </modules>
  <startup>
    <supportedRuntime version="v2.0.50727" sku="Client"/>
  </startup>
</configuration>

这工作！

我不知道为什么在App.config元素的顺序是非常重要的 - 但现在看来，这是

I'm not sure why the order of elements in the app.config is important - but it seems it is.