android - Android 中的 TimePickerDialog

Question

我正在尝试在 Android 中实现一个简单的 TimePickerDialog，但出现错误。我正在关注 Google 的本教程:https://developer.android.com/guide/topics/ui/controls/pickers.html

在我的代码中，我有一个名为 setFromTimeButton 的按钮，单击该按钮时应显示带有 TimePicker View 的 DialogFragment，但是，我有一个编译错误:

Cannot resolve symbol TimePickerFragment()

你知道为什么吗？谢谢!

这是我的课:

package it.bitrack.fabio.bitrack;

import android.content.Context;
import android.net.Uri;
import android.os.Bundle;
//import android.app.Fragment;
import android.support.v4.app.DialogFragment;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import java.util.List;

import android.app.Dialog;
import android.text.format.DateFormat;

import android.app.TimePickerDialog;
import android.app.DatePickerDialog;

import android.icu.util.Calendar;
import android.widget.DatePicker;
import android.widget.TimePicker;

import android.widget.Button;
import android.widget.TextView;


/**
 * A simple {@link Fragment} subclass.
 * Activities that contain this fragment must implement the
 * {@link ScheduleView.OnFragmentInteractionListener} interface
 * to handle interaction events.
 * Use the {@link ScheduleView#newInstance} factory method to
 * create an instance of this fragment.
 */
public class ScheduleView extends DialogFragment implements TimePickerDialog.OnTimeSetListener, DatePickerDialog.OnDateSetListener {
    // TODO: Rename parameter arguments, choose names that match
    // the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
    private static final String ARG_PARAM1 = "param1";
    private static final String ARG_PARAM2 = "param2";

    Button setFromTimeButton;

    android.support.v4.app.FragmentManager fragmentManager;

    // TODO: Rename and change types of parameters
    private String mParam1;
    private String mParam2;

    private OnFragmentInteractionListener mListener;

    public ScheduleView() {
        // Required empty public constructor
    }

    /**
     * Use this factory method to create a new instance of
     * this fragment using the provided parameters.
     *
     * @param param1 Parameter 1.
     * @param param2 Parameter 2.
     * @return A new instance of fragment ScheduleView.
     */
    // TODO: Rename and change types and number of parameters
    public static ScheduleView newInstance(String param1, String param2) {
        ScheduleView fragment = new ScheduleView();
        Bundle args = new Bundle();
        args.putString(ARG_PARAM1, param1);
        args.putString(ARG_PARAM2, param2);
        fragment.setArguments(args);
        return fragment;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        if (getArguments() != null) {
            mParam1 = getArguments().getString(ARG_PARAM1);
            mParam2 = getArguments().getString(ARG_PARAM2);
        }
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        View view = inflater.inflate(R.layout.fragment_schedule_view, container, false);

        setFromTimeButton = (Button) view.findViewById(R.id.setFromTimeButton);

        fragmentManager = getFragmentManager();

        setFromTimeButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                DialogFragment newFragment = new TimePickerFragment();
                newFragment.show(fragmentManager, "timePicker");
            }
        });


        return view;
    }


    // TODO: Rename method, update argument and hook method into UI event
    public void onButtonPressed(Uri uri) {
        if (mListener != null) {
            mListener.onFragmentInteraction(uri);
        }
    }

    @Override
    public void onAttach(Context context) {
        super.onAttach(context);
        if (context instanceof OnFragmentInteractionListener) {
            mListener = (OnFragmentInteractionListener) context;
        } else {
            throw new RuntimeException(context.toString()
                    + " must implement OnFragmentInteractionListener");
        }
    }

    @Override
    public void onDetach() {
        super.onDetach();
        mListener = null;
    }

    @Override
    public void onDateSet(DatePicker view, int year, int month, int dayOfMonth) {

    }

    @Override
    public void onTimeSet(TimePicker view, int hourOfDay, int minute) {

    }

    /**
     * This interface must be implemented by activities that contain this
     * fragment to allow an interaction in this fragment to be communicated
     * to the activity and potentially other fragments contained in that
     * activity.
     * <p>
     * See the Android Training lesson <a href=
     * "http://developer.android.com/training/basics/fragments/communicating.html"
     * >Communicating with Other Fragments</a> for more information.
     */
    public interface OnFragmentInteractionListener {
        // TODO: Update argument type and name
        void onFragmentInteraction(Uri uri);
    }


    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        // Use the current time as the default values for the picker
        final Calendar c = Calendar.getInstance();
        int hour = c.get(Calendar.HOUR_OF_DAY);
        int minute = c.get(Calendar.MINUTE);

        // Create a new instance of TimePickerDialog and return it
        return new TimePickerDialog(getActivity(), this, hour, minute,
                DateFormat.is24HourFormat(getActivity()));
    }
}

Answer 1

您需要添加以下类...

    public static class TimePickerFragment extends DialogFragment
                            implements TimePickerDialog.OnTimeSetListener {

    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        // Use the current time as the default values for the picker
        final Calendar c = Calendar.getInstance();
        int hour = c.get(Calendar.HOUR_OF_DAY);
        int minute = c.get(Calendar.MINUTE);

        // Create a new instance of TimePickerDialog and return it
        return new TimePickerDialog(getActivity(), this, hour, minute,
                DateFormat.is24HourFormat(getActivity()));
    }

    public void onTimeSet(TimePicker view, int hourOfDay, int minute) {
        // Do something with the time chosen by the user
    }
}

现在你可以调用它:

 DialogFragment newFragment = new TimePickerFragment();
 newFragment.show(fragmentManager, "timePicker");