How to include simple collections in ConfigurationSection

Question

Is there a way for me to include a simple array of strings, or List on my custom subclass of ConfigurationSection? (Or an array or generic list of simple data

Answer 1

Application Settings Architecture

http://msdn.microsoft.com/en-us/library/8eyb2ct1.aspx

Ok, an old post, but I remembered it when I came across a similar situation:

...

If you go to Project / Project Properties (in VS2008 or VS2010). There is a "Settings" tab.

If you add a new value....

One of the types is called: System.Collections.Specialized.StringCollection

Give it a name (I used "FavoriteColors").

Set the type (as instructed above).

Set the value(s).

The "String Collection Editor" says "Enter the strings in the collection (one per line)".

I entered:

Red

Yellow

Black

White

This will add some xml to your app.config file.

    <setting name="FavoriteColors" serializeAs="Xml">
        <value>
            <ArrayOfString xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
                xmlns:xsd="http://www.w3.org/2001/XMLSchema">
                <string>red</string>
                <string>yellow</string>
                <string>black</string>
                <string>white</string>
            </ArrayOfString>
        </value>
    </setting>

(You'll be better off going through the steps rather than pasting the xml above, because (for conciseness) I did not add all the xml to this post that is generated.

You should be able to "get at" the values via code like this:

private void ShowMyFavoriteColors()
{
            Properties.Settings.Default.FavoriteColors.Cast<string>().ToList().ForEach(myfavcolor =>
            {
                string temp = myfavcolor;
            });
}

Note, the steps above will produce the below C# code (auto code created for you.... it is not code you create) but the code looks like this:

        [global::System.Configuration.ApplicationScopedSettingAttribute()]
        [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
        [global::System.Configuration.DefaultSettingValueAttribute(@"<?xml version=""1.0"" encoding=""utf-16""?>
<ArrayOfString xmlns:xsi=""http://www.w3.org/2001/XMLSchema-instance"" xmlns:xsd=""http://www.w3.org/2001/XMLSchema"">
  <string>red</string>
  <string>yellow</string>
  <string>black</string>
  <string>white</string>
</ArrayOfString>")]
        public global::System.Collections.Specialized.StringCollection FavoriteColors {
            get {
                return ((global::System.Collections.Specialized.StringCollection)(this["FavoriteColors"]));
            }
        }
    }
}

Answer 2

OK, you asked for simple. Well, the simplest way to store a series of strings would be to use a delimited list (say, comma separated). That way you can store it in just one element (say in appSettings).

<add key="weekDays" value="Monday,Tuesday,Wednesday,Thursday,Friday"/>

Of course, this has drawbacks but in most cases works well for a simple list. You can then use String.Split() to convert it back to an array/list.

Otherwise you are back to ConfigurationSection elements which, I agree, are very verbose and clumsy to work with. But I don't know of any other way, I'm afraid (but am happy to be proved wrong!).

Answer 3

I know that the question has been answered long time ago... but in my 'ConfigurationElement' classes, for string collection, I usually do the following:

[ConfigurationProperty("myStringCollectionProperty", DefaultValue = "")]
[TypeConverter(typeof(CommaDelimitedStringCollectionConverter))]
public StringCollection MyStringCollectionProperty
{
    get { return (StringCollection)this["myStringCollectionProperty"]; }
    set { this["myStringCollectionProperty"] = value; }
 }

And you can get a string list from this property with

List<string> myStrings = config.MyStringCollectionProperty.Cast<string>.ToList()

Answer 4

Here's a simple example.

//START CODE


//MyCompany.MyProject.csproj which results in MyCompany.MyProject.dll
//Add a Folder called "Configuration"

namespace MyCompany.MyProject.Configuration
{
    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;

    using System.Configuration;


    public class TransformationToDirectoryMapping : ConfigurationElement
    {

        private const string FRIENDLY_NAME = "FriendlyName";
        private const string PICKUP_FOLDER = "PickupFolder";

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

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



    }

    //-----------------------------------------------------------------------

    //-----------------------------------------------------------------------

    [ConfigurationCollection(typeof(TransformationToDirectoryMapping))]
    public class TransformationToDirectoryMappingCollection : ConfigurationElementCollection
    {

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

        protected override object GetElementKey(ConfigurationElement element)
        {
            return ((TransformationToDirectoryMapping)(element)).PickupFolder;
        }


        public TransformationToDirectoryMapping this[int idx]
        {
            get
            {
                return (TransformationToDirectoryMapping)BaseGet(idx);
            }
        }

        new public TransformationToDirectoryMapping this[string key]
        {
            get
            {
                return (TransformationToDirectoryMapping)BaseGet(key);
            }
        }
    }

    //-----------------------------------------------------------------------

    //-----------------------------------------------------------------------

    public class TransformationToDirectoryMappingConfigSection : ConfigurationSection
    {
        private const string TRANSFORMATION_TO_DIRECTORY_MAPPINGS = "TransformationToDirectoryMappings";

        [ConfigurationProperty(TRANSFORMATION_TO_DIRECTORY_MAPPINGS)]
        public TransformationToDirectoryMappingCollection TransformationToDirectoryMappingItems
        {
            get { return ((TransformationToDirectoryMappingCollection)(base[TRANSFORMATION_TO_DIRECTORY_MAPPINGS])); }
        }
    }

    //-----------------------------------------------------------------------

    //-----------------------------------------------------------------------

    public static class MyRetriever
    {
        public const string MAPPINGS_CONFIGURATION_SECTION_NAME = "TransformationToDirectoryMappingsSection";

        public static TransformationToDirectoryMappingCollection GetTheCollection()
        {
            TransformationToDirectoryMappingConfigSection mappingsSection = (TransformationToDirectoryMappingConfigSection)ConfigurationManager.GetSection(MAPPINGS_CONFIGURATION_SECTION_NAME);
            if (mappingsSection != null)
            {
                return mappingsSection.TransformationToDirectoryMappingItems;
            }
            return null; // OOPS!

        }
    }

}

//XML for config file:

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <configSections>
    <section name="TransformationToDirectoryMappingsSection" type="MyCompany.MyProject.Configuration.TransformationToDirectoryMappingConfigSection, MyCompany.MyProject"/>
  </configSections>

  <TransformationToDirectoryMappingsSection>
    <TransformationToDirectoryMappings>
      <add FriendlyName="Hello" PickupFolder="C:\WUWUTemp\pickups\pickup11\" />
      <add FriendlyName="GoodBye" PickupFolder="C:\WUWUTemp\pickups\pickup12\" />
    </TransformationToDirectoryMappings>
  </TransformationToDirectoryMappingsSection>
</configuration>