// Add new DataType.
        // you need two object to add new DataType: DataTypeAddOptions and SettingController.
        // specify the field by drop-down box, You cannot add DataType with duplicate DataType's name.
        // You can add multiple field,For simplicity, only one field is added here.

        public async void AddNewDataType()
        {
            // get DataType name from EditText view,
            // The name must start with package name, and End with a custom name.
            string dataTypeName = DataTypeNameView.Text;
            // create DataTypeAddOptions,You must specify the Field that you want to add,
            // You can add multiple Fields here.
            DataTypeAddOptions dataTypeAddOptions =
                new DataTypeAddOptions.Builder().SetName(dataTypeName).AddField(SelectedField).Build();

            // create SettingController and add new DataType
            // The added results are displayed in the phone screen
            Task <DataType> AddTask = MySettingController.AddDataTypeAsync(dataTypeAddOptions);

            try
            {
                await AddTask;

                if (AddTask.IsCompleted)
                {
                    if (AddTask.Exception == null && AddTask.Result != null)
                    {
                        Logger("Add dataType of " + SelectedFieldStr + " is true ");
                    }
                    else
                    {
                        PrintFailureMessage(AddTask.Exception, "AddNewDataType");
                    }
                }
            }
            catch (System.Exception ex)
            {
                PrintFailureMessage(ex, "AddNewDataType");
            }
        }