Testing for equality between dictionaries in c#

dic1.Count == dic2.Count && !dic1.Except(dic2).Any();

It really depends on what you mean by equality.

This method will test that two dictionaries contain the same keys with the same values (assuming that both dictionaries use the same IEqualityComparer<TKey> implementation).

public bool CompareX<TKey, TValue>(
    Dictionary<TKey, TValue> dict1, Dictionary<TKey, TValue> dict2)
{
    if (dict1 == dict2) return true;
    if ((dict1 == null) || (dict2 == null)) return false;
    if (dict1.Count != dict2.Count) return false;

    var valueComparer = EqualityComparer<TValue>.Default;

    foreach (var kvp in dict1)
    {
        TValue value2;
        if (!dict2.TryGetValue(kvp.Key, out value2)) return false;
        if (!valueComparer.Equals(kvp.Value, value2)) return false;
    }
    return true;
}

You could use linq for the key/value comparisons:

public bool Compare<TKey, TValue>(Dictionary<TKey, TValue> dict1, Dictionary<TKey, TValue dict2)
{
    IEqualityComparer<TValue> valueComparer = EqualityComparer<TValue>.Default;

    return  dict1.Count == dict2.Count &&
            dict1.Keys.All(key => dict2.ContainsKey(key) && valueComparer.Equals(dict1[key], dict2[key]));
}