Load to combobox (WPF)

//this is my BusinessLayer in a form of class (DataAccessLayer)
//i have a class called Property and DataAccessLayer called BusinessLayer
//and again i have store procedure on a sqlDtatabase called allOfProparty

public DataTable AllofProperty()
        {
            using (SqlConnection sqlConn = new SqlConnection(ConnectionString))
            {
                SqlCommand sqlCmd = new SqlCommand("allOfProparty", sqlConn);
                sqlCmd.CommandType = CommandType.StoredProcedure;

                SqlDataAdapter sqlAdapter = new SqlDataAdapter(sqlCmd);

                DataTable ds = new DataTable();

                try
                {
                    sqlConn.Open();
                    sqlAdapter.Fill(ds);
                }
                catch (SqlException ex)
                {
                    throw new Exception(ex.Message);

                }
                return ds;
            }
        }