C# 导致配置加载错误的自定义App.config节

我正在使用app.config文件中的自定义配置部分，根据Jan Remunda在此处的帖子，在应用程序出现错误时自动向某些管理员发送电子邮件：

App.config：

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <startup> 
        <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5" />
  </startup>

  <configSections>
    <section name="ErrorEmailer" type="EmailTester.ErrorEmailer" />
  </configSections>

  <ErrorEmailer>
    <SmtpServer address="mail.smtphost.com" />
    <FromAddress address="from@host.com" />
    <ErrorRecipients>
      <ErrorRecipient address="example@example.com" />
      <ErrorRecipient address="example@example.com" />
    </ErrorRecipients>
  </ErrorEmailer>
</configuration>

此配置元素集合：

public class ErrorRecipients : ConfigurationElementCollection
{
    public ErrorRecipient this[int index]
    {
        get
        {
            return base.BaseGet(index) as ErrorRecipient;
        }
        set
        {
            if (base.BaseGet(index) != null)
            {
                base.BaseRemoveAt(index);
            }
            this.BaseAdd(index, value);
        }
    }

    public new ErrorRecipient this[string responseString]
    {
        get { return (ErrorRecipient)BaseGet(responseString); }
        set
        {
            if (BaseGet(responseString) != null)
            {
                BaseRemoveAt(BaseIndexOf(BaseGet(responseString)));
            }
            BaseAdd(value);
        }
    }

    protected override ConfigurationElement CreateNewElement()
    {
        return new ErrorRecipient();
    }

    protected override object GetElementKey(ConfigurationElement element)
    {
        return ((ErrorRecipient)element).Address;
    }
}

以及此配置部分：

public class ErrorEmailer : ConfigurationSection
{

    public static ErrorEmailer GetConfig()
    {
        return (ErrorEmailer)System.Configuration.ConfigurationManager.GetSection("ErrorEmailer") ?? new ErrorEmailer();
    }

    [ConfigurationProperty("ErrorRecipients")]
    [ConfigurationCollection(typeof(ErrorRecipients), AddItemName = "ErrorRecipient")]
    public ErrorRecipients ErrorRecipients
    {
        get
        {
            object o = this["ErrorRecipients"];
            return o as ErrorRecipients;
        }
    }

    [ConfigurationProperty("SmtpServer")]
    public SmtpServer SmtpServer
    {
        get
        {
            object o = this["SmtpServer"];
            return o as SmtpServer;
        }
    }

    [ConfigurationProperty("FromAddress")]
    public FromAddress FromAddress
    {
        get
        {
            object o = this["FromAddress"];
            return o as FromAddress;
        }
    }
}

但在运行程序并尝试运行此程序时，出现“配置系统初始化失败”错误：

var config = ErrorEmailer.GetConfig();
Console.WriteLine(config.SmtpServer.Address);

---

configSections

元素必须是

configuration

元素的第一个子元素。试试这个：

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <configSections>
    <section name="ErrorEmailer" type="EmailTester.ErrorEmailer" />
  </configSections>
  <startup> 
        <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5" />
  </startup>
  <ErrorEmailer>
    <SmtpServer address="mail.smtphost.com" />
    <FromAddress address="from@host.com" />
    <ErrorRecipients>
      <ErrorRecipient address="example@example.com" />
      <ErrorRecipient address="example@example.com" />
    </ErrorRecipients>
  </ErrorEmailer>
</configuration>

并按如下方式添加程序集：

<section name="ErrorEmailer"
         type="EmailTester.ErrorEmailer, My.Containing.Assembly.Goes.Here" />

---

如果您不使用.NET中包含的程序集限定配置类型的命名空间路径，则假定您指的是

System.Configuration

assembly。

谢谢，这消除了该问题，但现在我得到了创建ErrorEmailer的配置节处理程序时出错：无法从程序集“System.configuration，Version=4.0.0.0，Culture=neutral，PublicKeyToken=b03f5f7f11d50a3a”加载类型“EmailTester.ErrorEmailer”。“格式应为Namespace.ClassName，类型正确吗？非常感谢您快速、简洁的响应，修复了所有问题。”。将尽快接受。ErrorEmailer是否必须在启动元素中？

<section name="ErrorEmailer" type="EmailTester.ErrorEmailer" />

<section name="ErrorEmailer"
         type="EmailTester.ErrorEmailer, My.Containing.Assembly.Goes.Here" />