如何确定“ConfigurationElement”在“ConfigurationSection”自定义配置设置中可用

Posted 2023-03-04

【中文标题】如何确定“ConfigurationElement”在“ConfigurationSection”自定义配置设置中可用

【英文标题】：How to determine "ConfigurationElement" is available on "ConfigurationSection" custom configuration settings

【发布时间】：2017-07-06 14:11:58

【问题描述】：

我已经为我的应用程序编写了一个自定义配置，但是我没有找到正确的方法来确定 ConfigurationSection 中是否不存在任何 ConfigurationElement。

这是我的自定义配置 app.config 代码

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <configSections>
    <sectionGroup name="ApplicationsSettings" type="App.Configuration.ConfigurationGroup, App.Configuration.Core">
      <section name="DataExtractorSettings" type="App.Configuration.DataExtractorConfig, App.Configuration.Core" />
    </sectionGroup>
  </configSections>

  <ApplicationsSettings>
    <DataExtractorSettings>
      <executionLog>
        <enabled value="Y" />
        <copyOnReportDirectory value="Y" />
        <logFilePath value="D:\MyBatchProcessLog\MasterDataExtractor" />
      </executionLog>
      <eMail>
        <fromEmailID value="[e-mail]" />
        <webURL value="http://PROD/login.aspx" />
      </eMail>

  <!--<parallelProcessing>
        <allowed value="Y" />
        <threds value="6" />
      </parallelProcessing>-->

    </DataExtractorSettings>

  </ApplicationsSettings>

</configuration>

类 DataExtractorConfig

namespace App.Configuration

    [SettingProperty(Name: "dataExtractorSettings")]
    public class DataExtractorConfig : ConfigurationSection
    
        [ConfigurationProperty("executionLog")]
        public LogConfig ExecutionLog
        
            get
            
                if (base["executionLog"] != null)
                
                    return (LogConfig)base["executionLog"];
                
                else
                
                    return null;
                

            
        

        [ConfigurationProperty("parallelProcessing")]
        public ParallelProcessConfig ParallelProcessing
        
            get
            
                if (base["parallelProcessing"] != null)
                
                    return (ParallelProcessConfig)base["parallelProcessing"];
                
                else
                
                    return null;
                
            
        

        [ConfigurationProperty("eMail")]
        public EmailConfig Email
        
            get
            
                if (base["eMail"] != null)
                
                    return (EmailConfig)base["eMail"];
                
                else
                
                    return null;
                
            
        
    

这是从 App.config 文件中读取设置的代码

public static class ConfigurationReader


private const string _customSeetingParentNode = "ApplicationsSettings";

public static T GetSettings<T>(string configFileName = "AppSettings.xml", string sectionGroupName = "ApplicationsSettings")

    System.Configuration.Configuration config;
    ConfigurationSection customConfig;
    ExeConfigurationFileMap fileMap;
    T result;
    string settingKey;

    try
    
        fileMap = new ExeConfigurationFileMap();
        fileMap.ExeConfigFilename = string.Format("0\\1", AppDomain.CurrentDomain.BaseDirectory, configFileName);

        config = ConfigurationManager.OpenMappedExeConfiguration(fileMap, ConfigurationUserLevel.None);
        var caSetting = typeof(T).GetCustomAttributes(typeof(SettingProperty), false);

        string sectionName;
        dynamic dynSettingClass = null;
        if (caSetting != null && caSetting.Length > 0)
        
            settingKey = (caSetting[0] as SettingProperty).Name;
            sectionName = string.Concat(_customSeetingParentNode, "/", settingKey);
            customConfig = (ConfigurationSection)config.GetSection(sectionName);

            if (customConfig != null && customConfig.ElementInformation.IsPresent)
            
                //Here how do I determine the <parallelProcessing> setting is present or not in configuration file, 
                //like currently it is commented in app config file so the parallelProcessingExists should set with false

                //bool parallelProcessingExists = ?

                dynSettingClass = customConfig;
            
            else
            
                dynSettingClass = Activator.CreateInstance(typeof(T));
            

        
        else
        
            dynSettingClass = Activator.CreateInstance(typeof(T));
        

        result = (T)Convert.ChangeType(dynSettingClass, typeof(T));
        return result;
    
    finally
    
        config = null;
        customConfig = null;
        fileMap = null;
    

这是从 app.config 文件中读取设置的代码

DataExtractorConfig settigns = ConfigurationReader.GetSettings<DataExtractorConfig>();

我如何确定“parallelProcessing”设置是否存在于配置文件中，就像目前它在应用程序配置文件中注释一样，因此 parallelProcessingExists 应该设置为 false。

【问题讨论】：

通常，您不需要确定是否存在配置元素。您只需使用您声明的默认值。

@SimonMourier 问题是我在配置文件中还有一个部分是通用配置，如果其他任何设置没有，它也有“executionLog”、“eMail”和“parallelProcessing”节点有应该从公共部分加载的节点。例如，“DataExtractorSettings”部分中不存在“parallelProcessing”，因此它应该从公共部分加载。

【参考方案1】：

您创建了DataExtractorConfig 类，所以让我们使用它。从GetSection 方法返回的对象可以转换为DataExtractorConfig。现在您可以轻松访问ParallelProcessing、Email、ExecutionLog 属性并检查是否存在相应的配置部分。例如：

var customConfig = (DataExtractorConfig)config.GetSection(sectionName);

if (customConfig != null && customConfig.ElementInformation.IsPresent)

   if(customConfig.ParallelProcessing.ElementInformation.IsPresent)
   
      // TODO
   
   else
   
      // TODO
   

   dynSettingClass = customConfig;

【讨论】：

如果您从映射的 exe 配置中获取该部分，这似乎不起作用。有没有办法从映射的exe配置文件中做到这一点？