Question

我正在开发一个项目，其中包括用户将时间选择器选择的任何时间，但当我退出应用程序并再次打开时，所选时间消失了。

是否可以保存时间戳数据并在下次应用启动时使用它们？谢谢

import java.util.Calendar;
import java.util.concurrent.TimeUnit;

import android.app.Activity;
import android.app.AlarmManager;
import android.app.PendingIntent;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.content.SharedPreferences.Editor;
import android.os.Bundle;
import android.preference.PreferenceManager;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.TextView;
import android.widget.TimePicker;
import android.widget.Toast;
import android.widget.TimePicker.OnTimeChangedListener;

public class AndroidTimeActivity extends Activity {

    TimePicker myTimePicker;
    Button buttonstartSetDialog;
    Button buttonCancelAlarm;
    TextView textAlarmPrompt;

    private TimePicker timePicker;
    CheckBox optRepeat;
    SharedPreferences sPref;
    final static int RQS_1 = 1;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        timePicker = (TimePicker)findViewById(R.id.picker);
        optRepeat = (CheckBox)findViewById(R.id.optrepeat);
        textAlarmPrompt = (TextView)findViewById(R.id.alarmprompt);
        buttonstartSetDialog = (Button)findViewById(R.id.startSetDialog);
        TimePicker dp =  (TimePicker)this.findViewById(R.id.picker);
        dp.setCurrentHour(1);  
        //  
        dp.setCurrentMinute(01);  



        buttonstartSetDialog.setOnClickListener(new OnClickListener(){

            @Override
            public void onClick(View v) {

                Calendar calSet = Calendar.getInstance();

                calSet.set(Calendar.HOUR_OF_DAY, timePicker.getCurrentHour());
                calSet.set(Calendar.MINUTE, timePicker.getCurrentMinute());
                calSet.set(Calendar.SECOND, 0);
                calSet.set(Calendar.MILLISECOND, 0);



                setAlarm(calSet, optRepeat.isChecked());
            }});

        buttonCancelAlarm = (Button)findViewById(R.id.cancel);
        buttonCancelAlarm.setOnClickListener(new OnClickListener(){

            @Override
            public void onClick(View arg0) {
                cancelAlarm();
            }});


    }


    private void setAlarm(Calendar targetCal, boolean repeat){

        Intent intent = new Intent(getBaseContext(), AlarmReceiver.class);
        PendingIntent pendingIntent = PendingIntent.getBroadcast(getBaseContext(), RQS_1, intent, 0);
        AlarmManager alarmManager = (AlarmManager)getSystemService(Context.ALARM_SERVICE);



        if(repeat){
            alarmManager.setRepeating(AlarmManager.RTC_WAKEUP, 
                    targetCal.getTimeInMillis(), 
                    AlarmManager.INTERVAL_DAY,
                    pendingIntent);

            textAlarmPrompt.setText(
                    "\n\n***\n"
                    + "Alarm is set@ " + targetCal.getTime() + "\n"
                    + "Repeat\n"
                    + "***\n");
        }else{
            alarmManager.set(AlarmManager.RTC_WAKEUP, 
                    targetCal.getTimeInMillis(), 
                    pendingIntent);

            textAlarmPrompt.setText(
                    "\n\n***\n"
                    + "Alarm is set@ " + targetCal.getTime() + "\n"
                    + "One shot\n"
                    + "***\n");
        }

    }




    private void cancelAlarm(){

        textAlarmPrompt.setText(
                "\n\n***\n"
                + "Alarm Cancelled! \n"
                + "***\n");

        Intent intent = new Intent(getBaseContext(), AlarmReceiver.class);
        PendingIntent pendingIntent = PendingIntent.getBroadcast(getBaseContext(), RQS_1, intent, 0);
        AlarmManager alarmManager = (AlarmManager)getSystemService(Context.ALARM_SERVICE);
        alarmManager.cancel(pendingIntent);






    timePicker.setOnTimeChangedListener(new OnTimeChangedListener(){

        @Override
        public void onTimeChanged(TimePicker view, int hourOfDay, int minute) {
            Toast.makeText(getApplicationContext(), 
                    "onTimeChanged", Toast.LENGTH_SHORT).show();

        }});    

    }
}

编辑：感谢kruczjak，我找到了解决方案：

我在onclick中使用此代码，以便在单击按钮时将值保存到首选项

SharedPreferences.Editor editor = getPreferences(MODE_PRIVATE).edit(); editor.putInt("hour", timePicker.getCurrentHour()); editor.putInt("minute", timePicker.getCurrentMinute()); editor.commit();

并使用此代码打开首选项中最后保存的值

SharedPreferences prefs = getPreferences(MODE_PRIVATE); timePicker.setCurrentHour(prefs.getInt("hour", 1)); timePicker.setCurrentMinute(prefs.getInt("minute", 01));

Answer 1

尝试覆盖活动中的onStop()方法，并将代码保存到timePicker的某个地方（数据库，文件甚至共享首选项）。然后阅读并申请timePicker

中的onCreate()

请参阅此文章，了解更多http://developer.android.com/reference/android/app/Activity.html#ActivityLifecycle

的活动生命周期

Answer 2

将此代码添加到您的保存时间按钮

//Pref To save time picker  
SharedPreferences.Editor editor = getPreferences(MODE_PRIVATE).edit();
editor.putInt("hour", YourTimePicker.getCurrentHour());
editor.putInt("minute", YourTimePicker.getCurrentMinute());
editor.commit();

并在时间选择器活动的onCreate（）中调用此方法

public void  loadTimer(TimePicker timepicker) {
SharedPreferences prefs = getPreferences(MODE_PRIVATE);
timepicker.setCurrentHour(prefs.getInt("hour", 1));
timepicker.setCurrentMinute(prefs.getInt("minute", 01));
}

你会写

loadTimer(YourTimePicker);

是否可以保存timepicker的数据并在下次应用程序启动时显示它们？

2 个答案: