Question

我打开一个DatePickerFragment并选择一个新日期，但日期不会返回上一个片段的额外意图。我不确定为什么以及使用调试器进行仔细检查 “java.lang.ClassNotFoundException：[LObject;”当方法到达代码上的断点时。我正在关注BigNerdRanch教程。

这是我的CrimeFragment

public class CrimeFragment extends Fragment {
    private Crime mCrime;
    private EditText mTitleField;
    private Button mDateButton;
    private CheckBox mSolvedCheckBox;

    public static final String EXTRA_CRIME_ID =
            "xxx.com.criminalintent.crime_id";
    public static final String DIALOG_DATE = "date";
    public static final int REQUEST_DATE = 0;

    @Override
    public void onCreate(Bundle savedInstanceState){
        super.onCreate(savedInstanceState);
        UUID crimeId = (UUID)getArguments().getSerializable(EXTRA_CRIME_ID);

        mCrime = CrimeLab.get(getActivity()).getCrime(crimeId);


    }
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup parent, Bundle savedInstanceState){
        View v = inflater.inflate(R.layout.fragment_crime, parent, false);

        mTitleField = (EditText)v.findViewById(R.id.crime_title);
        mTitleField.setText(mCrime.getTitle());
        mTitleField.addTextChangedListener(new TextWatcher() {
            @Override
            public void beforeTextChanged(CharSequence c, int start, int count, int after) {
                //Left blank
            }

            @Override
            public void onTextChanged(CharSequence c, int start, int before, int count) {
                mCrime.setTitle(c.toString());

            }

            @Override
            public void afterTextChanged(Editable c) {
                // Left blank
            }
        });
        mDateButton = (Button)v.findViewById(R.id.crime_date);
        updateDate();
        mDateButton.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                FragmentManager fm = getActivity()
                        .getSupportFragmentManager();
                DatePickerFragment dialog = DatePickerFragment
                        .newInstance(mCrime.getDate());
                dialog.setTargetFragment(CrimeFragment.this, REQUEST_DATE);
                dialog.show(fm, DIALOG_DATE);


            }
        });

        mSolvedCheckBox = (CheckBox)v.findViewById(R.id.crime_solved);
        mSolvedCheckBox.setChecked(mCrime.isSolved());
        mSolvedCheckBox.setOnCheckedChangeListener(new OnCheckedChangeListener() {
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                //Set the crimes solved property.
                mCrime.setSolved(isChecked);
            }
        });

        return v;
    }
    public void updateDate(){
        mDateButton.setText(mCrime.getDate().toString());
    }
    public static CrimeFragment newInstance(UUID crimeId){
        Bundle args = new Bundle();
        args.putSerializable(EXTRA_CRIME_ID, crimeId);

        CrimeFragment fragment = new CrimeFragment();
        fragment.setArguments(args);

        return fragment;
    }
    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data){
        if(requestCode != Activity.RESULT_OK){
            return;
        }
        if(requestCode == REQUEST_DATE){
            Date date = (Date)data
                    .getSerializableExtra(DatePickerFragment.EXTRA_DATE);
            mCrime.setDate(date);
            updateDate();
        }
    }
}

这是我的DatePickerFragment

import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;

import android.app.Activity;
import android.app.AlertDialog;
import android.app.Dialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.DialogFragment;
import android.view.View;
import android.widget.DatePicker;
import android.widget.DatePicker.OnDateChangedListener;

/**
 * Created by xxx on 11/09/14.
 */
public class DatePickerFragment extends DialogFragment {

    public static final String EXTRA_DATE =
            "xxx.com.criminalintent.date";

    private Date mDate;


    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState){
        mDate = (Date)getArguments().getSerializable(EXTRA_DATE);

        //Create a calendar to view year, month, day.
        Calendar calendar = Calendar.getInstance();
        calendar.setTime(mDate);

        //Assign the calendar date to local variables.
        int year = calendar.get(Calendar.YEAR);
        int month = calendar.get(Calendar.MONTH);
        int day = calendar.get(Calendar.DAY_OF_MONTH);


        View v = getActivity().getLayoutInflater()
                .inflate(R.layout.dialog_date, null);

        DatePicker datePicker = (DatePicker)v.findViewById(R.id.dialog_date_datePicker);
        datePicker.init(year, month, day, new OnDateChangedListener(){
                public void onDateChanged(DatePicker view, int year, int month, int day){
                    mDate = new GregorianCalendar(year, month, day).getTime();
                    //Update argument to preserve values on rotation.
                    getArguments().putSerializable(EXTRA_DATE, mDate);
                }
        });


        return new AlertDialog.Builder(getActivity())
                .setView(v)
                .setTitle(R.string.date_picker_title)
                .setPositiveButton(
                        android.R.string.ok,
                        new DialogInterface.OnClickListener() {
                            public void onClick(DialogInterface dialog, int which) {
                                sendResult(Activity.RESULT_OK);
                            }
                        })
                .create();
    }

    /**
     * Static method to instanciate the DatePickerFragment
     * @param date
     * @return
     */
    public static DatePickerFragment newInstance(Date date){
        Bundle args = new Bundle();
        args.putSerializable(EXTRA_DATE, date);

        DatePickerFragment fragment = new DatePickerFragment();
        fragment.setArguments(args);

        return fragment;
    }

    private void sendResult(int resultCode){
        if(getTargetFragment() == null){
            return;
        }

        Intent i = new Intent();
        i.putExtra(EXTRA_DATE, mDate);
        getTargetFragment()
                .onActivityResult(getTargetRequestCode(), resultCode, i);

    }


}

Answer 1

onActivityResult()方法的第一个if语句看起来很可疑：requestCode != Activity.RESULT_OK。你可能想检查一下resultCode。

Intent extra不会返回onActivityResult上的上一个片段

1 个答案: