android - fragment 类中的 TimePickerDialog

Question

我可以实现吗

TimePickerDialog.OnTimeSetListener

在 fragment 类中？

如果可能怎么做？

这是我的TimePickerFragment.class

public class TimePickerFragment extends DialogFragment {


@NonNull
@Override

public Dialog onCreateDialog(Bundle savedInstanceState) {
    Calendar c = Calendar.getInstance();
    int cHour = c.get(Calendar.HOUR_OF_DAY);
    int cMinute = c.get(Calendar.MINUTE);

    return new TimePickerDialog(getActivity(), (TimePickerDialog.OnTimeSetListener) getActivity(), cHour, cMinute, android.text.format.DateFormat.is24HourFormat(getActivity()));
}
}

我是否需要修改此代码才能在 Fragment 类中使用它？

这就是我要实现它的地方

public class BluetoothFragment extends Fragment

我已经试过了但是我收到了这个错误

java.lang.ClassCastException: com.example.android.bluetoothplantdroid.MainActivity cannot be cast to android.app.TimePickerDialog$OnTimeSetListener

Answer 1

您可以将 Listener 设置为您的 DialogFragment 以在原始 fragment 中获取回调

public class TimePickerFragment extends DialogFragment {

    public static TimePickerFragment newInstance() {
        return new TimePickerFragment();
    }

    private TimePickerDialog.OnTimeSetListener listener;

    @NonNull
    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        Calendar c = Calendar.getInstance();
        int cHour = c.get(Calendar.HOUR_OF_DAY);
        int cMinute = c.get(Calendar.MINUTE);

        return new TimePickerDialog(getActivity(), listener, cHour, cMinute,
                android.text.format.DateFormat.is24HourFormat(getActivity()));
    }

    public void setListener(TimePickerDialog.OnTimeSetListener listener) {
        this.listener = listener;
    }
}

这就是你如何在原始 fragment 中获得回调 -

public class MyFragment extends Fragment implements TimePickerDialog.OnTimeSetListener {

   May be click event of some widget... {
       TimePickerFragment.newInstance().setListener(this);
       // Show your dialog
   }

    @Override
    public void onTimeSet(TimePicker view, int hourOfDay, int minute) {
        // data when time has been set.
    }

}