System.Text.StringBuilder.ToString C# (CSharp) Метод

		public override string ToString () 
		{
			if (_length == 0)
				return String.Empty;

			if (null != _cached_str)
				return _cached_str;

			// If we only have a half-full buffer we return a new string.
			if (_length < (_str.Length >> 1) || (_str.Length > string.LOS_limit && _length <= string.LOS_limit))
			{
				// use String.SubstringUnchecked instead of String.Substring
				// as the former is guaranteed to create a new string object
				_cached_str = _str.SubstringUnchecked (0, _length);
				return _cached_str;
			}

			_cached_str = _str;
			_str.InternalSetLength(_length);

			return _str;
		}

        public static EditProblemViewModel GetEditProblemViewModel(Problem problem)
        {
            var epvm = new EditProblemViewModel();
            epvm.Author = problem.Author.UserName;
            epvm.Name = problem.Name;
            epvm.Text = problem.Text;
            epvm.SelectedCategoryId = problem.CategoryId;
            epvm.IsBlocked = problem.IsBlocked;

            var sb = new StringBuilder();
            foreach (var tag in problem.Tags)
            {
                sb.Append(tag.Name);
                sb.Append(',');
            }

            epvm.TagsString = sb.ToString();

            sb.Clear();

            foreach (var ans in problem.CorrectAnswers)
            {
                sb.Append(ans.Text);
                sb.Append(';');
            }

            sb.Remove(sb.Length - 1, 1);
            epvm.Answers = sb.ToString();

            return epvm;
        }