StackOverflow2013

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POHow to use a handler to update my main Activity?
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copied!<p>I'm a beginner in Java/Android and I'm trying to increase my knowledge doing a simple game. You probably have ever heard about Genius.</p> <p>Well, here's my main activity code:</p> <pre><code>package br.genius; import java.util.ArrayList; import android.app.Activity; import android.os.Bundle; import android.view.View; import android.widget.Button; public class GeniusActivity extends Activity { /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); final Button b1 = (Button) findViewById(R.id.button1); final Button b2 = (Button) findViewById(R.id.button2); final Button b3 = (Button) findViewById(R.id.button3); final Button b4 = (Button) findViewById(R.id.button4); Button start = (Button) findViewById(R.id.button5); start.setOnClickListener(new View.OnClickListener() { public void onClick(View v) { Principal p = new Principal(b1,b2,b3,b4); } }); } public static void vermelho(int i, ArrayList<Button> alb) { alb.get(i).setBackgroundColor(-65536); } } </code></pre> <p>and here is my class extending a Thread:</p> <pre><code>package br.genius; import java.util.ArrayList; import java.util.Random; import android.widget.Button; public class Principal extends Thread implements Runnable{ private ArrayList<Button> alb = new ArrayList<Button>(); private Button b1,b2,b3,b4; private Thread tt; public Principal(Button b1,Button b2,Button b3,Button b4) { this.b1 = b1; this.b2 = b2; this.b3 = b3; this.b4 = b4; tt = new Thread(this); tt.start(); //this.run(); } public void run() { int ve[] = iniciaSequencia(); for (int i = 0; i < 4; i++) { switch (ve[i]) { case 1: alb.add(i, b1); break; case 2: alb.add(i, b2); break; case 3: alb.add(i, b3); break; case 4: alb.add(i, b4); break; } } for (int i = 0; i < 4; i++) { GeniusActivity.vermelho(i,alb); try { tt.wait(1500); } catch(InterruptedException e) { } //alb.get(i).setBackgroundColor(-7829368); } /*rr = new Runnable(){ public void run(){ for (int i = 0; i < 4; i++) { vermelho(i); //atrasador(); //alb.get(i).setBackgroundColor(-7829368); // } } };*/ } public int[] iniciaSequencia() { int v[] = new int[4]; Random r = new Random(); for (int i = 0; i < 4; i++) { v[i] = r.nextInt(4) + 1; } return v; } } </code></pre> <p>I'm getting an error called $CalledFromWrongThreadException : only the original thread that created a view hierarchy can touch its views.</p> <p>Thanks, Leo</p>

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