我的活动上有一个按钮，可以启动通知，然后启动带有异步任务的倒数计时器。代码的目的是将new.html.erb转换为可读时间并在第二个activity中将其发送到我的GUI我得到了这个致命的例外：
millisUntilFinishedHere他们说错误可能是因为尝试更新asynctask中的GUI，但这不是我的情况，因为í使用意图服务将变量发送到活动。我认为问题可能是我如何“设置”我的asynctask
接受按钮时的MainActivity类（P.S：很遗憾代码，如果它的一个但很乱:(）：
E/AndroidRuntime: FATAL EXCEPTION: AsyncTask #1
Process: com.idkbro.pashchallenge, PID: 25702
java.lang.RuntimeException: An error occurred while executing doInBackground()
at android.os.AsyncTask$3.done(AsyncTask.java:318)
at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:354)
at java.util.concurrent.FutureTask.setException(FutureTask.java:223)
at java.util.concurrent.FutureTask.run(FutureTask.java:242)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:243)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1133)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:607)
at java.lang.Thread.run(Thread.java:761)
Caused by: java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()
at android.os.Handler.<init>(Handler.java:200)
at android.os.Handler.<init>(Handler.java:114)
at android.os.CountDownTimer$1.<init>(CountDownTimer.java:114)
at android.os.CountDownTimer.<init>(CountDownTimer.java:114)
at com.idkbro.pashchallenge.MainActivity$1CDTTask$1.<init>(MainActivity.java:0)
at com.idkbro.pashchallenge.MainActivity$1CDTTask.doInBackground(MainActivity.java:250)
at com.idkbro.pashchallenge.MainActivity$1CDTTask.doInBackground(MainActivity.java:196)
at android.os.AsyncTask$2.call(AsyncTask.java:304)
at java.util.concurrent.FutureTask.run(FutureTask.java:237)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:243)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1133)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:607)
at java.lang.Thread.run(Thread.java:761)
如果有任何帮助，这是我的警报接收器类：
public void agreeButton (View v){
Intent intent = new Intent(MainActivity.this, CountdownPage.class);
startActivity(intent);
NotificationCompat.Builder notificationBuiler = new NotificationCompat.Builder(this)
.setContentTitle("Pash Challenge")
.setContentText("You have so many minutes left")//TODO make notification display countdown
.setTicker("Alert new message")
.setSmallIcon(R.drawable.pashicon);//Code to display notification
Intent moreInfoIntent = new Intent(MainActivity.this, MoreInfoNotification.class);
notificationManager =(NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
notificationManager.notify(notificationID,notificationBuiler.build());
// Used to stack tasks across activites so we go to the proper place when back is clicked
TaskStackBuilder tStackBuilder = TaskStackBuilder.create(this);
// Add all parents of this activity to the stack
tStackBuilder.addParentStack(MoreInfoNotification.class);
// Add our new Intent to the stack
tStackBuilder.addNextIntent(moreInfoIntent);
// Define an Intent and an action to perform with it by another application
// FLAG_UPDATE_CURRENT : If the intent exists keep it but update it if needed
PendingIntent pendingIntent = tStackBuilder.getPendingIntent(0,
PendingIntent.FLAG_UPDATE_CURRENT);
// Defines the Intent to fire when the notification is clicked
notificationBuiler.setContentIntent(pendingIntent);
isNotificationActive =true;
class CDTTask extends AsyncTask<Void, Void, Void>{
@Override
protected Void doInBackground(Void... params) {
Calendar calendar = Calendar.getInstance();
Long preTime = calendar.getTimeInMillis();
calendar.add(Calendar.DATE, 2);// set milliseconds for 2 days
Long postTime = calendar.getTimeInMillis();
Long delay = postTime - preTime;
AlarmManager manager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
manager.set(AlarmManager.RTC_WAKEUP, postTime, null);
CountDownTimer timer = new CountDownTimer(delay, 1) {
@Override
public void onTick(final long millisUntilFinished) {
runOnUiThread(new Runnable() {
@Override
public void run() {
//SendAndCovert milliseconds to CoundownPage
SAndCDays(millisUntilFinished);
SAndCHours(millisUntilFinished);
SAndCMinutes(millisUntilFinished);
SAndCSeconds(millisUntilFinished);
}//End run
});//End runOnUiThread
}//End onTick
@Override
public void onFinish() {
}//End OnFinish
void SAndCDays(Long milli){ //Code to convert milliseconds to days and send it to CountdownPage.java
Long millis = (milli / (1000*60*60*24));
String days = ""+millis;
Intent numIntent = new Intent(getApplicationContext(), CountdownPage.class);
numIntent.putExtra("days", days);
startActivity(numIntent);
}//End SAndCDays
void SAndCMinutes(Long milli){ //Code to convert milliseconds to minutes and send it to CountdownPage.java
long millis = ((milli / (1000 * 60)) % 60);
String minutes = ""+millis;
Intent numIntent = new Intent(getApplicationContext(), CountdownPage.class);
numIntent.putExtra("minutes", minutes);
startActivity(numIntent);
}//End SAndCMinutes
//Code to convert milliseconds to hours and send it to CountdownPage.java
void SAndCHours(Long milli){
long millis = (milli/ (1000 * 60 * 60)) % 24;
String hours = ""+millis;
Intent numIntent = new Intent(getApplicationContext(), CountdownPage.class);
numIntent.putExtra("hours", hours);
startActivity(numIntent);
}//End SAndCHours
//Code to convert milliseconds to seconds and send it to CountdownPage.java
void SAndCSeconds(Long milli){
long millis = (milli/ 1000) % 60;
String seconds = ""+millis;
Intent numIntent = new Intent(getApplicationContext(), CountdownPage.class);
numIntent.putExtra("seconds", seconds);
startActivity(numIntent);
} //End SAndCSeconds
};
timer.start();
return null;
}//End doInBackground
}
CDTTask object = new CDTTask();
object.execute();//Code to start Countdown Async task
} // End agreeButton
} //结束AlertReceiver.class
我如何从服务中接收和展示令人垂涎的时间：
public class AlertReceiver extends BroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent) {
createNotification(context, "Times Up", " x Seconds has past","alert");// TODO change to CDT Time
}//End onReceive
public void createNotification(Context context, String msg,
String txtMsg,String msgAlert) {
PendingIntent notificIntent = PendingIntent.getActivity(context, 0,
new Intent(context, MainActivity.class), 0);
// Builds a notification
NotificationCompat.Builder mBuilder =
new NotificationCompat.Builder(context)
.setSmallIcon(R.drawable.pashicon)
.setContentTitle(msg)
.setTicker(msgAlert)
.setContentText(txtMsg);
mBuilder.setContentIntent(notificIntent);
mBuilder.setDefaults(NotificationCompat.DEFAULT_SOUND);
mBuilder.setAutoCancel(true);
}//End createNotification