Question

我有一个拉出DatePicker片段的按钮，但我无法弄清楚如何根据所选日期更改视图。我在我的main.java中放置了onDateSet方法，这是调用片段的活动，意图改变了这个方法中的视图，但是当日期改变并且我不确定我做错了什么时它什么也没做。

public class DatePickerFragment extends DialogFragment implements DatePickerDialog.OnDateSetListener {

    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        // Use the current date as the default date in the picker
        final Calendar c = Calendar.getInstance();
        int year = c.get(Calendar.YEAR);
        int month = c.get(Calendar.MONTH);
        int day = c.get(Calendar.DAY_OF_MONTH);

        // Create a new instance of DatePickerDialog and return it
        return new DatePickerDialog(getActivity(), this, year, month, day);
    }

    public void onDateSet(DatePicker view, int year, int monthOfYear,
            int dayOfMonth) {
        // TODO Auto-generated method stub
    }

我的MainScreen.java是

public class MainScreen extends FragmentActivity implements DatePickerDialog.OnDateSetListener {

    static final int DATE_DIALOG_ID = 0;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main_screen);
    }

    public void showDatePickerDialog(View v) {
        DatePickerFragment newFragment = new DatePickerFragment();
        newFragment.show(getFragmentManager(), "datePicker");
    }

    public void onDateSet(DatePicker view, int year, int monthOfYear,
            int dayOfMonth) {

        Intent intent = new Intent(this, January_1.class);
        startActivity(intent);
    }
}

Answer 1

您应该在DatePickerFragement中使用onDateSet()侦听器：

public class DatePickerFragment extends DialogFragment implements DatePickerDialog.OnDateSetListener {

    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        // Use the current date as the default date in the picker
        final Calendar c = Calendar.getInstance();
        int year = c.get(Calendar.YEAR);
        int month = c.get(Calendar.MONTH);
        int day = c.get(Calendar.DAY_OF_MONTH);

        // Create a new instance of DatePickerDialog and return it
        return new DatePickerDialog(getActivity(), this, year, month, day);
    }

    public void onDateSet(DatePicker view, int year, int monthOfYear, int dayOfMonth) {
        Activity activity = getActivity();
        Intent intent = new Intent(activity, January_1.class);
        activity.startActivity(intent);
    }
}

从评论中添加

您使用monthOfYear的错误索引，来自the documentation：

monthOfYear 为了与Calendar兼容而设置的月份（0-11）。

所以1月是0，2月是1等等为了限制任何混淆，我建议使用Calendar类中的月份名称和switch语句：

Intent intent;
switch(monthOfYear) {
case Calendar.JANUARY:
    intent = new Intent(activity, January_1.class);
    break;
case Calendar.FEBRUARY:
    // etc...
}
activity.startActivity(intent);

选择日期后的DatePicker更改视图

1 个答案: