改写

我结合了我们讨论过的开发人员指南中的两个例子.现在,您应该能够理解如何将用户从TimePickerFragment中选择的时间发送回更有用的Activity. (我从第一个例子做了一些改变.)

TimePickerFragment：

public class TimePickerFragment extends DialogFragment {

// Notice I removed "implements OnTimeSetListener" and changed the variables

private Activity mActivity;

private OnTimeSetListener mListener;

@Override

public void onAttach(Activity activity) {

super.onAttach(activity);

mActivity = activity;

// This error will remind you to implement an OnTimeSetListener

// in your Activity if you forget

try {

mListener = (OnTimeSetListener) activity;

} catch (ClassCastException e) {

throw new ClassCastException(activity.toString() + " must implement OnTimeSetListener");

}

}

@Override

public Dialog onCreateDialog(Bundle savedInstanceState) {

// Use the current time as the default values for the picker

final Calendar c = Calendar.getInstance();

hour = c.get(Calendar.HOUR_OF_DAY);

minute = c.get(Calendar.MINUTE);

// Create a new instance of TimePickerDialog and return it

// I made a couple changes here!

return new TimePickerDialog(mActivity, mListener, hour, minute,

DateFormat.is24HourFormat(mActivity));

}

}

主要活动：

// add "implements OnTimeSetListener" to "public class MainActivity ..."

private int pickerHour = 0;

private int pickerMin = 0;

// onCreate() and your other methods...

public void showTimePickerDialog(View v) {

TimePickerFragment newFragment = new TimePickerFragment();

newFragment.show(getFragmentManager(), "timePicker");

}

@Override

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

// Do something with the time chosen by the user

pickerHour = hourOfDay;

pickerMin = minute;

}