Android datepicker双向数据绑定

<layout xmlns:android="http://schemas.android.com/apk/res/android">
    <data>
        <variable
            name="viewModel"
            type="com.example.MyViewModel" />
    </data>
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">
        <DatePicker
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:date="@={viewModel.selectedDate}" />
    </LinearLayout>
</layout>

public class MyViewModel extends ViewModel {
    private MutableLiveData<Date> selectedDate = new MutableLiveData<>();

    public LiveData<Date> getSelectedDate() {
        return selectedDate;
    }

    public void setSelectedDate(Date date) {
        selectedDate.setValue(date);
    }
}

public class MainActivity extends AppCompatActivity {
    private MyViewModel viewModel;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        ActivityMainBinding binding = DataBindingUtil.setContentView(this, R.layout.activity_main);
        viewModel = new ViewModelProvider(this).get(MyViewModel.class);
        binding.setViewModel(viewModel);
        binding.setLifecycleOwner(this);
        
        // 监听日期变化
        viewModel.getSelectedDate().observe(this, new Observer<Date>() {
            @Override
            public void onChanged(Date date) {
                // 处理日期变化事件
            }
        });
    }
}