app.config 自定义部分阅读答案

【问题标题】：app.config custom section readingapp.config 自定义部分阅读
【发布时间】：2014-03-26 08:05:33
【问题描述】：

我在从应用配置中读取自定义部分时遇到问题。我有

app.config：

<configuration>
  <configSections>
    <sectionGroup name="applicationSettings" type="System.Configuration.ApplicationSettingsGroup, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" >
      <section name="StartupFolders" type="Test.FolderConfiguration, Test"/>
    </sectionGroup>
  </configSections>

  <applicationSettings>
    <StartupFolders>
      <Folders>
        <Folder folderType="A" path="c:\foo" />
        <Folder folderType="B" path="C:\foo1" />
      </Folders>
    </StartupFolders>
  </applicationSettings>
</configuration>

文件夹配置.cs：

namespace Test
{
    public class FolderElement : ConfigurationElement
    {

        [ConfigurationProperty("folderType", DefaultValue = "", IsKey = true, IsRequired = true)]
        public string FolderType
        {
            get { return ((string)(base["folderType"])); }
            set { base["folderType"] = value; }
        }

        [ConfigurationProperty("path", DefaultValue = "", IsKey = false, IsRequired = false)]
        public string Path
        {
            get { return ((string)(base["path"])); }
            set { base["path"] = value; }
        }
    }

    [ConfigurationCollection(typeof(FolderElement))]
    public class FoldersCollection : ConfigurationElementCollection
    {
        protected override ConfigurationElement CreateNewElement()
        {
            return new FolderElement();
        }

        protected override object GetElementKey(ConfigurationElement element)
        {
            return ((FolderElement)(element)).FolderType;
        }

        public FolderElement this[int idx]
        {
            get { return (FolderElement)BaseGet(idx); }
        }
    }
    class FolderConfiguration : ConfigurationSection
    {
        [ConfigurationProperty("Folders")]
        public FoldersCollection FolderItems
        {
            get { return ((FoldersCollection)(base["Folders"])); }
        }
    }
}

最后在 MainWindow.cs 中我都使用它：

 Configuration cfg = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
            FolderConfiguration section = (FolderConfiguration)cfg.Sections["StartupFolders"];

它返回我 section == null。我无法理解我做错了什么。请帮忙

【问题讨论】：

标签： .net app-config

【解决方案1】：

class FolderConfiguration : ConfigurationSection
{
    [ConfigurationProperty("Folders")]
    [ConfigurationCollection(typeof(FoldersCollection), AddItemName = "Folder"]
    public FoldersCollection Folders
    {
        get { return ((FoldersCollection)(base["Folders"])); }
    }
}

另外，在您的 FolderElements 属性中，您有：

get { return ((string)(base["folderType"])); }
set { base["folderType"] = value; }

应该是：

get { return ((string)(this["folderType"])); }
set { this["folderType"] = value; }

这有帮助吗？

编辑

我的回答基于this

这会返回任何东西吗？ var folderConfig = ConfigurationManager.GetSection("StartupFolders") as FolderConfiguration; if( folderConfig != null) { //循环遍历集合 }

【讨论】：

没有异常或异常输出。程序正常运行。只是 folderConfig == null。乍一看，我和上面的页面差不多

【解决方案2】：

请看this question。它只有一个级别（在引用的问题中是用户），但我没有看到 StartupFolders->Folders->Folder 的原因。那么你只能拥有

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
    <configSections>
        <section name="Folders" type="ConsoleApplication1.FoldersConfigMapSection, ConsoleApplication1"/>
    </configSections>
    <Folders>
        <Folder folderType="A" path="c:\foo" />
        <Folder folderType="B" path="C:\foo1" />
    </Folders>
    <startup> 
        <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5" />
    </startup>
</configuration>

【讨论】：