How to programmatically change Active Directory password

Question

I have a set of test accounts that are going to be created but the accounts will be setup to require password change on the first login. I want to write a program in C# to

Answer 1

public void ResetPassword(string userName, string Password, string newPassword)
{
    try
    {
        DirectoryEntry directoryEntry = new DirectoryEntry(Path, userName, Password);

        if (directoryEntry != null)
        {
            DirectorySearcher searchEntry = new DirectorySearcher(directoryEntry);
            searchEntry.Filter = "(samaccountname=" + userName + ")";
            SearchResult result = searchEntry.FindOne();
            if (result != null)
            {
                DirectoryEntry userEntry = result.GetDirectoryEntry();
                if (userEntry != null)
                {
                    userEntry.Invoke("SetPassword", new object[] { newPassword });
                    userEntry.Properties["lockouttime"].Value = 0;
                }
            }
        }
    }
    catch (Exception ex)
    {
        Log.Error("Password Can't Change:" + ex.InnerException.Message);
    }
}