java - onResume 在从其他活动返回时表现不如预期

Question

我有一个小应用程序可以计算到指定日期和时间的时间。它运作良好。

import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.concurrent.TimeUnit;

import android.app.Activity;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.os.Handler;
import android.util.Log;
import android.view.Menu;
import android.widget.DigitalClock;
import android.widget.TextView;

public class Day2GoActivity extends Activity {
private TextView tvWeeks, tvDays, tvHours, tvMinutes, tvSeconds, timeUntil;


public Date curDateTime = new Date();
public Calendar today = Calendar.getInstance();
public Calendar leaving = Calendar.getInstance();
protected SimpleDateFormat sdf = new SimpleDateFormat("E dd-MMM-yyyy HH:mm");

protected Handler h = new Handler();
protected Runnable r = new Runnable() {
    public void run() {
        afficher();
    }
};

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    tvDays = (TextView) findViewById(R.id.tvDays);
    timeUntil = (TextView) findViewById(R.id.timeUntil);
    tvWeeks = (TextView) findViewById(R.id.tvWeeks);
    tvHours = (TextView) findViewById(R.id.tvHours);
    tvMinutes = (TextView) findViewById(R.id.tvMinutes);
    tvSeconds = (TextView) findViewById(R.id.tvSeconds);
}

@Override
protected void onResume() {
    super.onResume();
    Log.i("TAG", "Resuming");
    SharedPreferences sharedPreferences = getSharedPreferences("preferences", MODE_PRIVATE);
    Log.i("MyActvity", "Year = " + sharedPreferences.getInt("year", Calendar.YEAR));

    leaving.set(sharedPreferences.getInt("year", Calendar.YEAR), sharedPreferences.getInt("month", Calendar.MONTH),
            sharedPreferences.getInt("dayOfMonth", Calendar.DAY_OF_MONTH), sharedPreferences.getInt("hour", Calendar.HOUR_OF_DAY),
            sharedPreferences.getInt("minute", Calendar.MINUTE));
    timeUntil.setText("Time until: " + sdf.format(leaving.getTime()));
    r.run();
    Log.w("TAG", "Resumed");

}

private void afficher() {
    today = Calendar.getInstance();
    long millisToGo = leaving.getTimeInMillis() - today.getTimeInMillis();
    long seconds2go = TimeUnit.MILLISECONDS.toSeconds(millisToGo);
    tvSeconds.setText(String.format("%,d seconds", seconds2go));
    long minutes2go = TimeUnit.MILLISECONDS.toMinutes(millisToGo);
    tvMinutes.setText(String.format("%,d minutes", minutes2go));
    long hours2go = TimeUnit.MILLISECONDS.toHours(millisToGo);
    tvHours.setText(String.format("%d hours", hours2go));
    tvDays.setText(String.format("%d days %d hours", (int) hours2go / 24, hours2go % 24));
    long days2go = TimeUnit.MILLISECONDS.toDays(millisToGo);
    tvWeeks.setText(String.format("%d weeks %d days", (int) days2go / 7, days2go % 7));
    h.postDelayed(r, 1000);
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    Intent myIntent = new Intent(getApplicationContext(), editDate.class);
    startActivity(myIntent);
    return true;
}

但是，当用户更改日期和时间时，我遇到了问题。Activity正如你所见，我有第二个在onCreateOptionsMenu. 它也可以正常工作。

import java.util.Calendar;
import android.app.Activity;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.widget.DatePicker;
import android.widget.TimePicker;

public class editDate extends Activity {

protected DatePicker dp1;
protected TimePicker tp1;
protected Calendar c;

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.edit);
    dp1 = (DatePicker) findViewById(R.id.datePicker1);
    tp1 = (TimePicker) findViewById(R.id.timePicker1);
    tp1.setIs24HourView(true);
    LoadPreferences();
}

@Override
protected void onDestroy() {
    super.onDestroy();
    SavePreferences();
}

private void SavePreferences() {
    SharedPreferences sharedPreferences = this.getSharedPreferences("preferences", MODE_PRIVATE);
    SharedPreferences.Editor editor = sharedPreferences.edit();

    editor.putInt("year", dp1.getYear());
    editor.putInt("month", dp1.getMonth());
    editor.putInt("dayOfMonth", dp1.getDayOfMonth());
    editor.putInt("hour", tp1.getCurrentHour());
    editor.putInt("minute", tp1.getCurrentMinute());
    editor.commit();
}

private void LoadPreferences() {
    SharedPreferences sharedPreferences = this.getSharedPreferences("preferences", MODE_PRIVATE);
    c = Calendar.getInstance();

    try {
        dp1.init(sharedPreferences.getInt("year", c.YEAR), sharedPreferences.getInt("month", c.MONTH),
                sharedPreferences.getInt("dayOfMonth", c.DAY_OF_MONTH), null);
    } catch (IllegalArgumentException e) {
        // TODO Auto-generated catch block
        dp1.init(2012, 5, 1, null);
    }
    tp1.setCurrentHour(sharedPreferences.getInt("hour", c.HOUR_OF_DAY));
    tp1.setCurrentMinute(sharedPreferences.getInt("minute", c.MINUTE));
}

}

该应用程序运行良好，Log cat 文件中包含所有预期的条目：

06-01 18:21:04.049: I/ApplicationPackageManager(7750): cscCountry is not German : XEU
06-01 18:21:04.079: I/TAG(7750): Resuming
06-01 18:21:04.089: I/MyActvity(7750): Year = 2014
06-01 18:21:04.089: W/TAG(7750): Resumed
06-01 18:21:05.459: W/KeyCharacterMap(7750): No keyboard for id 0
06-01 18:21:05.459: W/KeyCharacterMap(7750): Using default keymap:    /system/usr/keychars/qwerty.kcm.bin
06-01 18:21:05.519: I/ApplicationPackageManager(7750): cscCountry is not German : XEU
06-01 18:21:05.619: W/Picker(7750): beforeTextChanged: 01, 0, 2, 2
06-01 18:21:05.619: W/Picker(7750): onTextChanged: 01
06-01 18:21:05.619: W/Picker(7750): onTextChanged: 01, 0, 2, 2
06-01 18:21:05.619: W/Picker(7750): aftertextchanged: 01
06-01 18:21:05.619: W/Picker(7750): beforeTextChanged: 01, 0, 2, 2
06-01 18:21:05.619: W/Picker(7750): onTextChanged: 01
06-01 18:21:05.619: W/Picker(7750): onTextChanged: 10, 0, 2, 2
06-01 18:21:05.619: W/Picker(7750): aftertextchanged: 10
06-01 18:21:05.619: W/Picker(7750): beforeTextChanged: 2012, 0, 4, 4
06-01 18:21:05.619: W/Picker(7750): onTextChanged: 2012
06-01 18:21:05.619: W/Picker(7750): onTextChanged: 2014, 0, 4, 4
06-01 18:21:05.619: W/Picker(7750): aftertextchanged: 2014
06-01 18:21:08.239: E/DatePicker(7750): adjustMaxDat : 31 10
06-01 18:21:08.239: W/Picker(7750): beforeTextChanged: 10, 0, 2, 2
06-01 18:21:08.249: W/Picker(7750): onTextChanged: 10
06-01 18:21:08.249: W/Picker(7750): onTextChanged: 01, 0, 2, 2
06-01 18:21:08.249: W/Picker(7750): aftertextchanged: 01
06-01 18:21:08.259: W/Picker(7750): beforeTextChanged: 01, 0, 2, 2
06-01 18:21:08.259: W/Picker(7750): onTextChanged: 01
06-01 18:21:08.259: W/Picker(7750): onTextChanged: 10, 0, 2, 2
06-01 18:21:08.259: W/Picker(7750): aftertextchanged: 10
06-01 18:21:08.259: W/Picker(7750): beforeTextChanged: Jun, 0, 3, 3
06-01 18:21:08.259: W/Picker(7750): onTextChanged: Jun
06-01 18:21:08.259: W/Picker(7750): onTextChanged: Jul, 0, 3, 3
06-01 18:21:08.269: W/Picker(7750): aftertextchanged: Jul
06-01 18:21:10.759: I/TAG(7750): Resuming
06-01 18:21:10.759: I/MyActvity(7750): Year = 2014
06-01 18:21:10.759: W/TAG(7750): Resumed

但是它不会更新TextView. timeUntil()我可以相信我在这里做错了什么，但有两个问题。首先，在启动时（之后）运行时timeUntil()更新，其次，如果您更改屏幕的方向，则更新。我知道屏幕重新定向会重新运行，这表明它在一个之后工作，但在单独运行时不工作。我完全不知所措。onResume()onCreate()timeUntil()onCreate()onResume()onCreate()

有没有人有任何想法？

根据 Proxy32 的输入（见下文），我已将onResumevoid 更改为

@Override
protected void onResume() {
    super.onResume();

    timer.scheduleAtFixedRate(new TimerTask() {
        public void run() {
            h.post(new Runnable() {
                @Override
                public void run() {
                    Log.i("TAG", "Resuming");
                    SharedPreferences sharedPreferences = getSharedPreferences("preferences", MODE_PRIVATE);
                    Log.i("MyActvity", "Year = " + sharedPreferences.getInt("year", Calendar.YEAR));

                    leaving.set(sharedPreferences.getInt("year", Calendar.YEAR), sharedPreferences.getInt("month", Calendar.MONTH),
                            sharedPreferences.getInt("dayOfMonth", Calendar.DAY_OF_MONTH),
                            sharedPreferences.getInt("hour", Calendar.HOUR_OF_DAY), sharedPreferences.getInt("minute", Calendar.MINUTE));
                    Log.d("TAG", "date " + sdf.format(leaving.getTime()));
                    timeUntil.setText("Time until: " + sdf.format(leaving.getTime()));
                    timeUntil.invalidate();
                    today = Calendar.getInstance();
                    long millisToGo = leaving.getTimeInMillis() - today.getTimeInMillis();
                    long seconds2go = TimeUnit.MILLISECONDS.toSeconds(millisToGo);
                    tvSeconds.setText(String.format("%,d seconds", seconds2go));
                    long minutes2go = TimeUnit.MILLISECONDS.toMinutes(millisToGo);
                    tvMinutes.setText(String.format("%,d minutes", minutes2go));
                    long hours2go = TimeUnit.MILLISECONDS.toHours(millisToGo);
                    tvHours.setText(String.format("%,d hours", hours2go));
                    tvDays.setText(String.format("%,d days %d hours", (int) hours2go / 24, hours2go % 24));
                    long days2go = TimeUnit.MILLISECONDS.toDays(millisToGo);
                    tvWeeks.setText(String.format("%,d weeks %d days", (int) days2go / 7, days2go % 7));
                }
            });
        }
    }, 0, 1000);
    Log.w("TAG", "Resumed");

}

我也删除了affcher。这现在做了我想要它做的事情。问题解决了。

score 1 · Accepted Answer

我不确定我是否理解这个问题，但我会尽力澄清我能做的。

onResume 在 onStart（和/或 onRestart）之后在 onCreate 之后被调用。这就是为什么它会在您更改屏幕配置后或应用程序首次启动时按照您的建议运行。

有关详细信息，请参阅：http: //developer.android.com/reference/android/app/Activity.html#ActivityLifecycle

这也意味着当您返回原始主要活动时，应该更新 timeUntil。但是，我没有在您的代码中看到您完成补充活动的位置。此外，您所说的“自行运行”是什么意思？

score 0 · Accepted Answer

0

设置文本后尝试 TextView invalidate() 方法

于 2012-06-01T18:31:09.373 回答

java - onResume 在从其他活动返回时表现不如预期

2 回答 2

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