If you create a class like Setting<T>, you might think you can create a generic list, like:

List<Setting<T>> List = new List<Setting<T>>();

,but this is not possible in .Net 4.0. If you want objects of type Setting<int> mixed with objects of type  Setting<bool> in one List<T> you must define a none generic base class Setting, like:

public class Setting { private string _name; public string Name { get { if (string.IsNullOrEmpty(_name)) {

throw new ApplicationException("Property [Name] in class [Setting] is null or empty"); } return _name; } set { _name = value; } } } [Serializable] public class Setting<T> : Setting { private T _value; public T Value { get { return _value; } set { _value = value; } } public Type Type { get { return typeof(T); } } /// <summary> /// Define a default constructor for serialization purposes /// </summary> public Setting() { } }

Then you can mix generic types in the generic list like:

List<Setting> list = new List<Setting>
{
    new Setting<int>{Name = "Timeout", Value = 1000},
    new Setting<bool>{Name = "ImportEnabled", Value = true}
};

You can get an element of this list by using the method:

public T GetSetting<T>(string name, List<Setting> list)
{     T result;
    Setting<T> setting = (Setting<T>)Convert.ChangeType(
                         list.Single(s => s.Name.Equals(name)), typeof(Setting<T>), null); result = setting.Value; return result; }

To call the method use:

int timeout = GetSetting<int>("Timeout", list);

3 Comments

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.