.NET自定义配置部分:Configuration.GetSection抛出'无法定位程序集'异常

Question

我为插件DLL创建了一个自定义配置部分,它将.config XML存储在一个单独的(来自主可执行应用程序)文件中.

以下是自定义部分类的示例:

using System;   
using System.Configuration;

namespace PluginFramework.MyConfiguration
{

public class MyConfigurationSettings : ConfigurationSection
{
    private Configuration _Config = null;

    #region ConfigurationProperties     
    /// <summary>
    /// A custom XML section for an application's configuration file.
    /// </summary>
    [ConfigurationProperty("MyProjects", IsDefaultCollection = true)]
    public MyProjectConfigurationCollection MyProjects
    {
        get { return (MyProjectConfigurationCollection) base["MyProjects"]; }
    }

    // ...
    #endregion

    /// <summary>
    /// Private Constructor used by our factory method.
    /// </summary>
    private MyConfigurationSettings () : base () {
        // Allow this section to be stored in user.app. By default this is forbidden.
        this.SectionInformation.AllowExeDefinition =
        ConfigurationAllowExeDefinition.MachineToLocalUser;
    }

    // ...

    #region Static Members  
    /// <summary>
    /// Gets the current applications &lt;MyConfigurationSettings&gt; section.
    /// </summary>
    /// <param name="ConfigLevel">
    /// The &lt;ConfigurationUserLevel&gt; that the config file
    /// is retrieved from.
    /// </param>
    /// <returns>
    /// The configuration file's &lt;MyConfigurationSettings&gt; section.
    /// </returns>
    public static MyConfigurationSettings GetSection (ConfigurationUserLevel ConfigLevel) 
    {
        string appDataPath = System.Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData);
        string localDataPath = System.Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData);
        System.Configuration.ExeConfigurationFileMap exeMap = new ExeConfigurationFileMap();
        exeMap.ExeConfigFilename = System.IO.Path.Combine(appDataPath, @"MyCompany\MyPluginApp\Default.config");
        exeMap.RoamingUserConfigFilename = System.IO.Path.Combine(appDataPath, @"MyCompany\MyPluginApp\Roaming.config");
        exeMap.LocalUserConfigFilename = System.IO.Path.Combine(localDataPath, @"MyCompany\MyPluginApp\Local.config");

        System.Configuration.Configuration Config = ConfigurationManager.OpenMappedExeConfiguration(exeMap,ConfigLevel);
        MyConfigurationSettings myConfigurationSettings = null;

        try {
            myConfigurationSettings = (MyConfigurationSettings)Config.GetSection("MyConfigurationSettings");
        } 
        catch (System.Exception ex) {
            // ConfigurationErrorsException caught here ...
        }
        if (myConfigurationSettings == null) {
            myConfigurationSettings = new MyConfigurationSettings();
            Config.Sections.Add("MyConfigurationSettings", myConfigurationSettings);                    }
        } 
        if(myConfigurationSettings != null) {
            myConfigurationSettings._Config = Config;
        }

        return myConfigurationSettings;
    }       
    #endregion
}
} // PluginFramework.MyConfiguration

保存第一次时生成的.config XML如下所示:

<?xml version="1.0" encoding="utf-8"?>
<configuration>
    <configSections>
        <!-- The exception complains about the following line (assembly attributes are compliant): -->
        <section name="MyConfigurationSettings" type="PluginFramework.MyConfiguration.MyConfigurationSettings, PluginFramework, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" allowDefinition="Everywhere" allowExeDefinition="MachineToLocalUser" />
    </configSections>
    <MyConfigurationSettings>
        <!-- Config properties are serialized fine according MyConfigurationSettings 
             properties marked with the ConfigurationProperty attribute ... -->
        <MyProjects>
            <MyProjectConfiguration GUID="{4307AC92-8180-4686-9322-830312ED59AB}">
                <!-- ... more complex configuration elements -->
            </MyProjectConfiguration>
        </MyProjects>
    </MyConfigurationSettings>
</configuration>

当尝试Config.GetSection()在后续运行时使用此XML加载时,我会ConfigurationErrorsException在XML示例中标记的行中找到,指出MyPlugin无法找到程序集或其中一个依赖项(请原谅我没有发布原始文件)异常消息,但我只有德语,并怀疑这个文本在这里会有所帮助).内部异常来自于System.IO尝试加载程序集并获得反射以解析"MyConfigurationSettings"类类型.

为了精确这种情况,上面的代码放在框架DLL(程序集)中,而框架DLL(程序集)又由从主应用程序加载的实际插件DLL引用.

以下UML图说明了几个组件的关系:

在仔细研究了这个问题之后,我觉得有必要强化名称(签名)导出MyConfigurationSettings类(即PluginFramework)的程序集并将其注册到GAC.我还没有尝试过这个,并且想要避免这一步骤有几个原因(在知道它是否可以帮助之前,它是解决问题的唯一选择).

所以这里有一些问题(对不起,我实际上在这里提出了4个问题,但它们之间的联系非常紧密,因此为它们创建单独的SO问题是没有意义的).

1. 我是否可以通过强有力地命名有问题的程序集并将其注册到GAC来解决定位失败问题？

2. 愚蠢的配置管理抱怨的程序集,保证加载(因为它Configuration.GetSection()自己调用).
   是否有可能使用ConfigurationManager或Confguration类显式注册程序集或相应的配置类型de-/serializers ？

3. 我也对有关Hans Passant的评论的更多信息感兴趣,提到这可能是由主应用程序加载(主要)程序集的方式引起的问题.我无法控制这种机制,如果这导致这种行为本身我想知道是否有合理的解决方法？

4. 另一个想法(如果上述任何内容未能显示方法)是本机地完全管理配置XML格式(使用XML解/序列化支持)以及从何处加载和合并配置文件.如果这是最合适的选项,那么任何人都可以给出如何有效地执行此操作(用于管理路径和合并的最不必要的代码)吗？

更新:
由于似乎没有人能够对这个问题给出更多的见解(2个答案并没有让我更进一步),我正在改为4的选项,手动完成所有操作.

Answer 1

我也尝试过，但我从来没有让它像那样工作。我只是认为自动加载 .config 不适用于 .dll，仅适用于 .exe。然后我放弃了，并决定手动加载 .config 文件会更容易。您可以在此处查看完整代码：https://github.com/GeertBellekens/Enterprise-Architect-Toolpack/blob/master/EANavigator/NavigatorSettings.cs 这是最相关的部分：

public NavigatorSettings() {
     Configuration roamingConfig = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.PerUserRoaming);

     // the roamingConfig now get a path such as C:\Users\<user>\AppData\Roaming\Sparx_Systems_Pty_Ltd\DefaultDomain_Path_2epjiwj3etsq5yyljkyqqi2yc4elkrkf\9,_2,_0,_921\user.config
     // which I don't like. So we move up three directories and then add a directory for the EA Navigator so that we get
     // C:\Users\<user>\AppData\Roaming\GeertBellekens\EANavigator\user.config
     string configFileName =  System.IO.Path.GetFileName(roamingConfig.FilePath);
     string configDirectory = System.IO.Directory.GetParent(roamingConfig.FilePath).Parent.Parent.Parent.FullName;

     string newConfigFilePath = configDirectory + @"\Geert Bellekens\EANavigator\" + configFileName;
     // Map the roaming configuration file. This
     // enables the application to access 
     // the configuration file using the
     // System.Configuration.Configuration class
     ExeConfigurationFileMap configFileMap = new ExeConfigurationFileMap();
     configFileMap.ExeConfigFilename = newConfigFilePath;       

     // Get the mapped configuration file.
     currentConfig = ConfigurationManager.OpenMappedExeConfiguration(configFileMap, ConfigurationUserLevel.None);
     // merge the default settings
     this.mergeDefaultSettings();
 }

访问配置属性：

public bool trackSelectedElement
{
    get {
        bool result;
        if(bool.TryParse(this.currentConfig.AppSettings.Settings["trackSelectedElement"].Value, out result)) {
            return result;
        }
        else {
            return true;
        }
    }
    set {
        this.currentConfig.AppSettings.Settings["trackSelectedElement"].Value = value.ToString();
    }
}