How to convert object to Dictionary<TKey, TValue> in C#?

The above answers are all cool. I found it easy to json serialize the object and deserialize as a dictionary.

var json = JsonConvert.SerializeObject(obj);
var dictionary = JsonConvert.DeserializeObject<Dictionary<string, string>>(json);

I don't know how performance is effected but this is much easier to read. You could also wrap it inside a function.

public static Dictionary<string, TValue> ToDictionary<TValue>(object obj)
{       
    var json = JsonConvert.SerializeObject(obj);
    var dictionary = JsonConvert.DeserializeObject<Dictionary<string, TValue>>(json);   
    return dictionary;
}

Use like so:

var obj = new { foo = 12345, boo = true };
var dictionary = ToDictionary<string>(obj);

I use this helper:

public static class ObjectToDictionaryHelper
{
    public static IDictionary<string, object> ToDictionary(this object source)
    {
        return source.ToDictionary<object>();
    }

    public static IDictionary<string, T> ToDictionary<T>(this object source)
    {
        if (source == null)
            ThrowExceptionWhenSourceArgumentIsNull();

        var dictionary = new Dictionary<string, T>();
        foreach (PropertyDescriptor property in TypeDescriptor.GetProperties(source))
            AddPropertyToDictionary<T>(property, source, dictionary);
        return dictionary;
    }

    private static void AddPropertyToDictionary<T>(PropertyDescriptor property, object source, Dictionary<string, T> dictionary)
    {
        object value = property.GetValue(source);
        if (IsOfType<T>(value))
            dictionary.Add(property.Name, (T)value);
    }

    private static bool IsOfType<T>(object value)
    {
        return value is T;
    }

    private static void ThrowExceptionWhenSourceArgumentIsNull()
    {
        throw new ArgumentNullException("source", "Unable to convert object to a dictionary. The source object is null.");
    }
}

the usage is just to call .ToDictionary() on an object

Hope it helps.