Retrieving a generic type value from an object dictionary without exceptions

Question

Is there a generic way (preferably with an extension method) that you can retrieve values (could be decimal, short, int or string) casted to the right type from a Dictionary<string, object> without it failing when the key does not exist?

Answer 1

you can do the following:

using System;
using System.Collections.Generic;

public static class DictionaryExtensions
{
    public static T GetValue<T>(this Dictionary<string, object> dictionary, string key)
    {
        object value = null;
        if (!dictionary.TryGetValue(key, out value))
        {
            throw new KeyNotFoundException(key);
        }

        return (T)Convert.ChangeType(value, typeof(T));
    }
}

edit: If you don't want it to throw anything, just remove the line that throws a new KeyNotFoundException. I find it handy to have that, because KeyNotFoundException never includes the friggin name of the column not found. This way, the error message will BE the column name :-)