我有一个小应用程序，用于计算指定日期和时间之前的时间。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。我有第二个Activity，你可以在onCreateOptionsMenu中看到它。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));
}
}
该应用程序正常运行，其中包含Log cat文件中的所有预期条目：
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的{{1}}。我可以相信我在这里做错了但是有两个问题。首先timeUntil()在启动时运行timeUntil()时更新（onResume()之后），其次onCreate()，如果更改屏幕方向，则会更新IS。我了解屏幕的重新定位会重新显示timeUntil()，这表示onCreate()在onResume()之后正在运行，但在自行运行时却没有。我完全不知所措。
有没有人有任何想法？
根据Proxy32的输入（见下文），我已将onCreate() void更改为
onResume我也删除了。现在这就是我想做的事情。问题解决了。
答案 0 :(得分：1)
我不确定我是否理解这个问题，但我会尽力澄清我的能力。
在onCreate之后，在onStart（和/或onRestart）之后调用onResume。这就是为什么它在您更改屏幕配置或应用程序首次启动后的行为方式。
详情请见： http://developer.android.com/reference/android/app/Activity.html#ActivityLifecycle
这也意味着当您返回到原始主活动时应该更新timeUntil。但是，我在您的代码中没有看到您正在完成补充活动。另外，“你自己跑？”是什么意思？
答案 1 :(得分：0)
设置文本
后尝试TextView invalidate（）方法