App.config file replace the keyword "key"and "value"

Question

I will be as specific as possible. I have the above configuration that I retrieve and use it. What I want is to change the keywords of "key" to "car" and "value" to "brand Number".

Is this Possible ?

I tried Retrieving the values after changing the keyword names but doesn't work with the current code to retrieve the keys/values.

  <!-- Custom section in App.config file. -->

    <configSections>
    <section
      name="CarMapping"
      type="System.Configuration.AppSettingsSection" />
  </configSections>
    <startup> 
        <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5"/>
    </startup>

  <!-- Mapping the cars to specific brandNumber. -->
  <CarMapping>
    <add key="1" value="A"/>
    <add key="2" value="B"/>
    <add key="3" value="C"/>
    <add key="4" value="A"/>
    <add key="5" value="D" />    
  </CarMapping>

Code for getting the key/values from App.config file and store it to Dictionary.

            // Get the configuration file.
            System.Configuration.Configuration config = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);

            // Get the appSettings section.
            AppSettingsSection appSettings = (AppSettingsSection)config.GetSection("CarMapping");

            // Get the settings collection (key/value pairs).
                foreach (string key in appSettings.Settings.AllKeys)
                {
                    string value = appSettings.Settings[key].Value;
                    string keyValue = appSettings.Settings[key].Key;

                Console.WriteLine(appSettings.Settings[key].Key);

                    MyDectionary.Add(keyValue, value); }        

This is what I want. Please let me know the code for retrieving the "car" and "brandNumber". Thank you in advance.

  <!-- Mapping the cars to specific brandNumber. -->
  <CarMapping>
    <add car="1" brandNumber="A"/>
    <add car="2" brandNumber="B"/>
    <add car="3" brandNumber="C"/>
    <add car="4" brandNumber="A"/>
    <add car="5" brandNumber="D" />    
  </CarMapping>

Answer 1

You'll need to create your own specialized overloads to get that working. For your specific configuration file requirements you'll need three new classes: One to handle the section, one to handle the Collection and one to handle the element in that collection.

Section

The configuration section is the top-level container for your config. It doubles for the Collection container as well. The override of the Properties member does that by returning the configuration property for being a collection.

class CarSection : ConfigurationSection
{
    [ConfigurationProperty("", IsDefaultCollection = false)]
    [ConfigurationCollection(typeof(CarCollection),
        AddItemName = "add",
        ClearItemsName = "clear",
        RemoveItemName = "remove")]
    public CarCollection Cars
    {
        get
        {

            return (CarCollection)base[property];
        }
    }

    static ConfigurationProperty  property = new ConfigurationProperty(null, typeof(CarCollection), null, ConfigurationPropertyOptions.IsDefaultCollection);
    protected override ConfigurationPropertyCollection Properties
    {
        get
        {
            var configurationPropertyCollection = new ConfigurationPropertyCollection();
            configurationPropertyCollection.Add(property);
            return configurationPropertyCollection;
        }
    }
}

Collection

This is a default, straightforward implementation of an configuration collection. It acts as a factory for new CarElements.

class CarCollection : ConfigurationElementCollection
{
    protected override ConfigurationElement CreateNewElement()
    {
        return new CarElement();
    }

    protected override object GetElementKey(ConfigurationElement element)
    {
        var carElement = element as CarElement;
        if (carElement != null)
        {
            var car = (CarElement)carElement;
            return car.Car;
        }
        return null;
    }
}

ConfigurationElement

The CarElement class is capable of deserializing the new attributes car and Brandnumber. I assumed the car is the key here. That can be changed though.

class CarElement: ConfigurationElement
{

    [ConfigurationProperty("car", DefaultValue = "42",
    IsRequired = true, IsKey = true)]
    public string Car { get { return (string)this["car"]; } set { this["car"] = value; } }

    [ConfigurationProperty("brandNumber", DefaultValue = "42",
    IsRequired = true, IsKey = true)]
    public string BrandNumber { get { return (string)this["brandNumber"]; }  set { this["car"] = value; } }
}

When you want to leverage this, you have to make this change in your app.config to bring your own classes into play:

<configSections>
    <section
      name="CarMapping"
      type="ConsoleApplication2.CarSection, ConsoleApplication2" />
</configSections>

Make sure to fully qualify the type, so both the type AND assemblyname.

Reading the car mappings is done with this code:

System.Configuration.Configuration config = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);

// Get the appSettings section.
var carSettings = (CarSection)config.GetSection("CarMapping");

//Get the settings collection (key / value pairs).
foreach (CarElement car in carSettings.Cars)
{

    Console.WriteLine("{0} - {1} ", car.BrandNumber, car.Car);
}