/// <summary>
/// Check exist this nikname in the users list
/// </summary>
/// <param name="nikName">Nikname of the user</param>
/// <returns></returns>
private static bool IsExistNikName(string nikName)
{
if (_userDataList.Count == 0)
{
return false;
}
// here I use a lambda expression for the searching the nikname in the user data list
_user = _userDataList.FirstOrDefault(userData => userData.Nikname == nikName);
if (String.IsNullOrEmpty(_user.Nikname))
{
return false;
}
return true;
}
/// <summary>
/// Saving the new user
/// </summary>
/// <param name="user"></param>
/// <returns></returns>
public static bool Save(UserData user)
{
if (!IsExistNikName(user.Nikname))
{
_userDataList.Add(user);
using (Stream fileStream = File.Create(FileName))
{
var serializer = new XmlSerializer(typeof(List<UserData>));
serializer.Serialize(fileStream, _userDataList);
}
return true;
}
return false;
}