在LiveData Observable中使用@IntDef

Question

我正在研究如何更新一些现有代码以使用新的Android LiveData架构模式。希望代码示例是自我解释的，我很难让@IntDef / @Interface与Live Data一起工作。我很高兴在ViewModel上为SetAnsweredCorrectly，SetCheated等创建方法，或者创建一个MutableLiveData属性并在代码中设置它，我只是在努力查看如何使用除正常Integer之外的任何东西，这会失去类型安全

public class QuestionViewModel extends ViewModel {

    public static final int UNANSWERED = 0;
    public static final int ANSWERED_CORRECTLY = 1;
    public static final int ANSWERED_INCORRECTLY = 2;
    public static final int CHEATED = 3;

    @IntDef({UNANSWERED, ANSWERED_CORRECTLY, ANSWERED_INCORRECTLY, CHEATED})
    @Retention(RetentionPolicy.SOURCE)
    public @interface AnswerState{}

    private @AnswerState int answeredState;

    public Question()
    {
        this.setAnsweredState(UNANSWERED);
    }

    public @AnswerState int getAnsweredState() {
        return answeredState;
    }

    public void setAnsweredState(@AnswerState int answeredState) {
        this.answeredState = answeredState;
    }

Answer 1

尝试一下：

ObservableField<AnswerState> observableAnswer = new ObservableField<>;