How to implement a ConfigurationSection with a ConfigurationElementCollection

Question

I am trying to implement a custom configuration section in a project and I keep running up against exceptions that I do not understand. I am hoping someone can fill in the blanks here.

I have App.config that looks like this:

<?xml version="1.0" encoding="utf-8" ?> <configuration>     <configSections>         <section name="ServicesSection" type="RT.Core.Config.ServicesConfigurationSectionHandler, RT.Core"/>     </configSections>     <ServicesSection type="RT.Core.Config.ServicesSection, RT.Core">             <Services>                 <AddService Port="6996" ReportType="File" />                 <AddService Port="7001" ReportType="Other" />             </Services>         </ServicesSection> </configuration> 

I have a ServiceConfig element defined like so:

public class ServiceConfig : ConfigurationElement   {     public ServiceConfig() {}      public ServiceConfig(int port, string reportType)     {       Port = port;       ReportType = reportType;     }      [ConfigurationProperty("Port", DefaultValue = 0, IsRequired = true, IsKey = true)]     public int Port      {       get { return (int) this["Port"]; }       set { this["Port"] = value; }     }      [ConfigurationProperty("ReportType", DefaultValue = "File", IsRequired = true, IsKey = false)]     public string ReportType     {       get { return (string) this["ReportType"]; }       set { this["ReportType"] = value; }     }   } 

And I have a ServiceCollection defined like so:

public class ServiceCollection : ConfigurationElementCollection   {     public ServiceCollection()     {       Console.WriteLine("ServiceCollection Constructor");     }      public ServiceConfig this[int index]     {       get { return (ServiceConfig)BaseGet(index); }       set       {         if (BaseGet(index) != null)         {           BaseRemoveAt(index);         }         BaseAdd(index, value);       }     }      public void Add(ServiceConfig serviceConfig)     {       BaseAdd(serviceConfig);     }      public void Clear()     {       BaseClear();     }      protected override ConfigurationElement CreateNewElement()     {       return new ServiceConfig();     }      protected override object GetElementKey(ConfigurationElement element)     {       return ((ServiceConfig) element).Port;     }      public void Remove(ServiceConfig serviceConfig)     {       BaseRemove(serviceConfig.Port);     }      public void RemoveAt(int index)     {       BaseRemoveAt(index);     }      public void Remove(string name)     {       BaseRemove(name);     }   } 

The part I am missing is what to do for the handler. Originally, I tried to implement an IConfigurationSectionHandler but found two things:

1. it didn't work
2. it's deprecated.

I'm completely lost now on what to do so I can read my data from config. Any help please!

Answer 1

The previous answer is correct but I'll give you all the code as well.

Your app.config should look like this:

<?xml version="1.0" encoding="utf-8" ?> <configuration>    <configSections>       <section name="ServicesSection" type="RT.Core.Config.ServiceConfigurationSection, RT.Core"/>    </configSections>    <ServicesSection>       <Services>          <add Port="6996" ReportType="File" />          <add Port="7001" ReportType="Other" />       </Services>    </ServicesSection> </configuration> 

Your ServiceConfig and ServiceCollection classes remain unchanged.

You need a new class:

public class ServiceConfigurationSection : ConfigurationSection {    [ConfigurationProperty("Services", IsDefaultCollection = false)]    [ConfigurationCollection(typeof(ServiceCollection),        AddItemName = "add",        ClearItemsName = "clear",        RemoveItemName = "remove")]    public ServiceCollection Services    {       get       {          return (ServiceCollection)base["Services"];       }    } } 

And that should do the trick. To consume it you can use:

ServiceConfigurationSection serviceConfigSection =    ConfigurationManager.GetSection("ServicesSection") as ServiceConfigurationSection;  ServiceConfig serviceConfig = serviceConfigSection.Services[0];