SimplyGold

.NET 3.5 brought with it the new System.DirectoryServices.AccountManagement namespace, which makes working with Active Directory so much easier. Let's take a look at how to find a user if you know their username (SAMAccountName):

private static UserPrincipal GetPrincipal(string name)
{
    var context = new PrincipalContext(
        ContextType.Domain, "yourdomain.com");

    var principal = UserPrincipal.FindByIdentity(
        context, IdentityType.SamAccountName, name);

    return principal;
}

Wow, three entire lines of code. I don't know how we'll ever convince anyone to switch from the old way of doing things. :-) How about getting the user's groups?

PrincipalSearchResult<Principal> GetGroups(UserPrincipal principal)
{
    return principal.GetAuthorizationGroups();  
}

How about you just want to dump properties about that principal?

private static IDictionary<string, string> GetProperties(UserPrincipal principal)
{
    var properties = new Dictionary<string, string>();

    var directoryEntry = principal.GetUnderlyingObject() as DirectoryEntry;

    var allProperties = directoryEntry.Properties;

    foreach (var property in allProperties.PropertyNames)
    {
        var propertyName = property.ToString();

        var value = string.Empty;

        if (allProperties[propertyName] != null && allProperties[propertyName].Count > 0)
        {
            foreach (var val in allProperties[propertyName])
            {
                if (val != null)
                {
                    value += ", " + val.ToString();
                }
            }
        }

        properties.Add(property.ToString(), value); 
    }

    return properties;
}