Question

Here’s the problem. I would like to create a class which will contain configuration data. This data consists of key/value pairs. Some examples: “hostName”=”localhost”, “timeout”=1000, etc.. My initial idea was to store all these in a generic dictionary:

private Dictionary<string, ConfigurationItem<object>> Configuration = 
    new Dictionary<string, ConfigurationItem<object>>();

And the ConfigurationItem class as:

public class ConfigurationItem<T>
{
    public string Name { get; set; }
    public T Value { get; set; }
}

My hopes are that I can query and set the configuration as follows:

int i = Configuration.Get<int>("Timeout");
Configuration.Set("Timeout", 1000);

Unfortunately, I can’t insert items in the configuration dictionary using the following code:

public void SetValue<T>(string key, ConfigurationItem<T> value)
{
        if (Configuration.ContainsKey(key.ToUpper()))
            Configuration[key.ToUpper()] = **value**;
        else
            Configuration.Add(key.ToUpper(),  **value**);
}

The bold parts are showing errors:

Cannot convert type ConfigurationItem<T> to ConfigurationItem<Object>

I am using C# 4.0 since I hoped to fixed this problem using the new variance feature, but no luck so far. If more information is needed, just name it! Thanks for your help!

Answer 1

You could just define your Dictionary as private Dictionary<string, object>, and cast the objects before you return them from your Get method.