Sudoku using Microsoft Solver Foundation

using System.Collections.Generic;
using System.Windows;

namespace Sudoku
{
    public static class GameController
    {
        public static void GenerateNewGame()
        {
            SudokuProblem.GenerateProblem();
        }

        public static List<int> GetSudokuSolution()
        {
            if (SudokuProblem.GetSolution().Count == 0)
            {
                SudokuProblem.GenerateProblem();
            }
            return SudokuProblem.GetSolution();
        }

        public static List<int> GetSudokuProblem()
        {
            if (SudokuProblem.GetProblem().Count == 0)
            {
                SudokuProblem.GenerateProblem();
            }
						if (!SudokuProblem.HasUniqueSolution())
						{
							MessageBox.Show("Multiple solutions");
						}
            return SudokuProblem.GetProblem();
        }

        public static void IsSudokuSolved(List<int> solution)
        {
            if (solution == null)
            {
                return;
            }

            if (!solution.Contains(Constants.PlaceHolder))
            {
                if (SudokuProblem.IsSolved(solution))
                {
                    MessageBox.Show("Congratulations!");
                }
            }
        }
    }
}