Question

我有一个包含EditText的片段，当我点击EditText时，会出现一个DatePicker对话框来选择日期。
的 FragmentFile

public class FirstFragment extends Fragment {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_first, container, false);
        EditText editText = (EditText) view.findViewById(R.id.visitDateFiled);

        editText.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                DialogFragment picker = new DatePickerFragment();
                picker.show(getFragmentManager(), "Date Picker");
            }
        });
        return view;
    }

DialogFragment

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);
    }

    @Override
    public void onDateSet(DatePicker view, int year, int month, int day) {
        Calendar c = Calendar.getInstance();
        c.set(year, month, day);

        SimpleDateFormat sdf = new SimpleDateFormat("dd-MM-yyyy");
        String formattedDate = sdf.format(c.getTime());

    }
}

问题我不知道如何将数据（选定日期）从DialogFragment传递到Fragment？
我读了一些话题，但它没有让我感到困惑（很抱歉再次提出这个问题）。

Topic 1 Topic 2

Answer 1

更新了代码

的 FragmentFile

public class FirstFragment extends Fragment implements DatePickerDialogFragmentEvents{ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); } @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { View view = inflater.inflate(R.layout.fragment_first, container, false); EditText editText = (EditText) view.findViewById(R.id.visitDateFiled); editText.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { DialogFragment picker = new DatePickerFragment(); picker.setDatePickerDialogFragmentEvents(FirstFragment.this); //Changed picker.show(getFragmentManager(), "Date Picker"); } }); return view; } //This is where you will get selected date value @Override public void onDateSelected(String date) { String selectedDate = date; } }

DialogFragment

public class DatePickerFragment extends DialogFragment implements DatePickerDialog.OnDateSetListener { //Interface created for communicating this dialog fragment events to called fragment public interface DatePickerDialogFragmentEvents{ void onDateSelected(String date); } DatePickerDialogFragmentEvents dpdfe public void setDatePickerDialogFragmentEvents(DatePickerDialogFragmentEvents dpdfe){ this.dpdfe = dpdfe; } @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); } @Override public void onDateSet(DatePicker view, int year, int month, int day) { Calendar c = Calendar.getInstance(); c.set(year, month, day); SimpleDateFormat sdf = new SimpleDateFormat("dd-MM-yyyy"); String formattedDate = sdf.format(c.getTime()); dpdfe.onDateSelected(formattedDate); //Changed } }

因此，我在dialogfragment类中创建了一个名为DatePickerDialogFragmentEvents的接口，并在调用者片段中实现了该接口。在创建dialogfragment实例时从调用者片段，使用对话框片段类的setDatePickerDialogFragmentEvents方法设置片段的DatePickerDialogFragmentEvents实例。

Answer 2

我已经解决了问题，感谢this topic，主题的第二次回应。
的 DatePickerFragment.java

@Override public void onDateSet(DatePicker view, int year, int month, int day) { Calendar c = Calendar.getInstance(); c.set(year, month, day); SimpleDateFormat sdf = new SimpleDateFormat("dd-MM-yyyy"); String formattedDate = sdf.format(c.getTime()); // in this part I stored the selected date into the intent Intent i = new Intent(); i.putExtra("selectedDate",formattedDate); getTargetFragment().onActivityResult(getTargetRequestCode(), Activity.RESULT_OK, i); }

片段文件

public static final int DATEPICKER_FRAGMENT=1; // adding this line @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { View view = inflater.inflate(R.layout.fragment_feeding, container, false); EditText editText = (EditText) view.findViewById(R.id.foodDeliveryDateFiled); editText.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { DialogFragment picker = new DatePickerFragment(); picker.setTargetFragment(FeedingFragment.this, DATEPICKER_FRAGMENT); picker.show(getFragmentManager().beginTransaction(), "Date Picker"); } }); return view; } @Override public void onActivityResult(int requestCode, int resultCode, Intent data) { switch(requestCode) { case DATEPICKER_FRAGMENT: if (resultCode == Activity.RESULT_OK) { // here the part where I get my selected date from the saved variable in the intent and the displaying it. Bundle bundle=data.getExtras(); String resultDate = bundle.getString("selectedDate","error"); EditText editText = (EditText) getView().findViewById(R.id.foodDeliveryDateFiled); editText.setText(resultDate); } break; }

Answer 3

每个Java程序员的第一个响应是创建一个可观察或回调并发送它。虽然这在大多数地方都是可接受的做法，但在使用Fragments和DialogFragments时，由于状态在重新创建，旋转，暂停时会丢失，因此体验并不那么漂亮......您必然会收到您不期望的IllegalStateExceptions。

我的建议虽然有点激烈，但会将您的通信模式从一系列接口回调转移到集中式事件总线，如Otto或GreenRobot。对于任何给定的状态，它在前景和后台都很有用，并有助于解耦使用。

Answer 4

使用 ViewModel 是最好的解决方案

START TRANSACTION; 
UPDATE `db_2019`.`table_2020` SET UpdateField = UpdateValue; 
UPDATE `db_2020`.`table_2021` SET UpdateField = UpdateValue; 
...
COMMIT;

According to Android Documentation

将数据从DialogFragment发送到Fragment

4 个答案: