安卓: TimePickerDialog - TimePickerDialog.OnTimeSetListener

Question

我是Android的新手。我再次提出另一个“简单”的问题。我希望你能帮助我。我只想要一个在对话框中显示TimePicker的按钮。当我在时间选择器中设置时间时，我希望得到所选的时间。我使用的是安卓支持库和ActionbarSherlock。这是我的代码：

AddPeriod.java

import android.app.AlertDialog;
import android.app.TimePickerDialog;
import android.content.DialogInterface;
import android.os.Bundle;
import android.support.v4.app.DialogFragment;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ListView;
import com.actionbarsherlock.app.ActionBar;
import com.actionbarsherlock.app.SherlockFragmentActivity;
import com.actionbarsherlock.view.MenuItem;

public class AddPeriod extends SherlockFragmentActivity {


    @Override
    protected void onCreate(Bundle savedInstanceState) {        
        super.onCreate(savedInstanceState);
        setContentView(R.layout.add_period); 
    }

    public void showTimePickerDialog(View v) {
        DialogFragment newFragment = new TimePickerFragment();
        newFragment.show(getSupportFragmentManager(), "timePicker");
    }

    TimePickerDialog.OnTimeSetListener mTimeSetListener =
            new TimePickerDialog.OnTimeSetListener() {
                @Override
                public void onTimeSet(android.widget.TimePicker view,
                        int hourOfDay, int minute) {
                    Log.i("",""+hourOfDay+":"+minute);
                }
            };
}

add_period.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <Button 
        android:id="@+id/btn"
        android:layout_width="wrap_content" 
        android:layout_height="wrap_content"
        android:text="Escoge hora" 
        android:onClick="showTimePickerDialog" />

</LinearLayout>

TimePickerFragment.java

import android.text.format.DateFormat;
import java.util.Calendar;

import android.app.Dialog;
import android.support.v4.app.DialogFragment;

import android.app.TimePickerDialog;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.widget.TimePicker;

public 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

    }
}

但听众并没有被召唤。有什么建议吗？也许这个问题已经得到了回答，但经过30分钟的搜索，我发现answer.Thanks对我的帮助并不多。

Answer 1

在AddPeriod.java中，您可以创建一个TimePickerDialog.OnTimeSetListener，但据我所见，没有使用侦听器。

在TimePickerFragment.java中，您实现了TimePickerDialog.OnTimeSetListener接口，并将片段实例本身作为侦听器传递给TimePickerDialog，但是在TimePickerFragment.java中的已实现的onTimeSet()方法中什么也不做。您是说onTimeSet()在TimePickerFragment.java中没有被调用吗？你设置了断点吗？

如果您设法在片段中调用了onTimeSet()，那么我假设您真正要求的是如何将这一次传递回活动。如果我是对的，我会说这里是使用事件总线的完美场所，例如使用奥托。

更新:根据您对我的问题的评论，我认为您真正想要的是一种将TimePickerFragment中选定的时间带回AddPeriod的方法。在我看来，更好的方法是使用事件总线(如前所述)。这将使您的片段与您的活动脱钩。但是，为了给出对代码进行最小更改的答案，我建议您将侦听器传递到片段，并在创建对话框时使用该侦听器：

TimePickerFragment.java：

public class TimePickerFragment extends DialogFragment {

    private TimePickerDialog.OnTimeSetListener listener;

    public TimePickerFragment(TimePickerDialog.OnTimeSetListener listener) {
        super();
        this.listener = listener;
    }

    @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(), listener, hour, minute,
        DateFormat.is24HourFormat(getActivity()));
    }
}

如您所见，我添加了一个接受TimePickerDialog.OnTimeSetListener参数的构造函数。创建TimePickerDialog时使用此侦听器。现在，在我们的AddPeriod活动中，当创建mTimeSetListener时，我们将它传递给该片段：

public class AddPeriod extends SherlockFragmentActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {        
        super.onCreate(savedInstanceState);
        setContentView(R.layout.add_period); 
    }

    public void showTimePickerDialog(View v) {
        DialogFragment newFragment = new TimePickerFragment(mTimeSetListener);
        newFragment.show(getSupportFragmentManager(), "timePicker");
    }

    TimePickerDialog.OnTimeSetListener mTimeSetListener =
            new TimePickerDialog.OnTimeSetListener() {
                @Override
                public void onTimeSet(android.widget.TimePicker view,
                        int hourOfDay, int minute) {
                    Log.i("",""+hourOfDay+":"+minute);
                }
            };
}