CODEWITHSUNDEEP
javaandroidtimer
user3482237
user3482237

Reputation: 27

timer.scheduleAtFixedRate have an exception

my code is:

ou=100
final Timer t=new Timer();
TimerTask tt=new TimerTask() {              
       @Override
       public void run() {
           ou-=10;
           if(ou==0)
               btnstart.setText(btnstart.getText().toString()+"t");

      }};
t.scheduleAtFixedRate(tt, 2000, 2000);

but when I run this program when change btnstart.text program will be close with this error "unfortunately, has stopped"

this is my log cat:

07-01 15:27:30.714: W/dalvikvm(973): threadid=11: thread exiting with uncaught exception (group=0x40a13300)
07-01 15:27:30.786: E/AndroidRuntime(973): FATAL EXCEPTION: Timer-0
07-01 15:27:30.786: E/AndroidRuntime(973): java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()
07-01 15:27:30.786: E/AndroidRuntime(973): at android.os.Handler.(Handler.java:121)
07-01 15:27:30.786: E/AndroidRuntime(973): at android.widget.Toast$TN.(Toast.java:322)
07-01 15:27:30.786: E/AndroidRuntime(973): at android.widget.Toast.(Toast.java:91)
07-01 15:27:30.786: E/AndroidRuntime(973): at android.widget.Toast.makeText(Toast.java:238)
07-01 15:27:30.786: E/AndroidRuntime(973): at ir.maghsoodi.reminders.MainActivity$1$1.run(MainActivity.java:45)
07-01 15:27:30.786: E/AndroidRuntime(973): at java.util.Timer$TimerImpl.run(Timer.java:284)

Upvotes: 1

Views: 668

Answers (2)

JohnUopini
JohnUopini

Reputation: 970

You can not update the UI from another thread, you need to use an Handler as explained here, or (much easier in my opinion) use the eventbus library

Upvotes: 1

Marco Acierno
Marco Acierno

Reputation: 14847

TimerTask is executed in another Thread (TimerThread) and you can't update UI elements from a thread which is not the main.

Use btnstart.post( Runnable ) to execute the code inside UI Thread.

Example

if(ou==0) {
 btnstart.post(new Runnable() {
   @Override
   public void run() {
     btnstart.setText(btnstart.getText().toString()+"t");
   }
 });
}

Upvotes: 2

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