Update View at runtime in Android
- by seretur
The example is pretty straightforward: i want to let the user know about what the app is doing by just showing a text (canvas.drawText()). Then, my first message appears, but not the other ones. I mean, i have a "setText" method but it doesn't updates.
onCreate(Bundle bundle) {
super.onCreate(bundle);
setContentView(splash); // splash is the view class
loadResources();
splash.setText("this");
boundWebService();
splash.setText("that"):
etc();
splash.setText("so on");
}
The view's text drawing works by doing just a drawText in onDraw();, so setText changes the text but doesn't show it.
Someone recommended me replacing the view with a SurfaceView, but it would be alot of trouble for just a couple of updates, SO... how the heck can i update the view dinamically at runtime?
It should be quite simple, just showing a text for say 2 seconds and then the main thread doing his stuff and then updating the text...
Thanks!
Update:
I tried implementing handler.onPost(), but is the same story all over again. Let me put you the code:
package coda.tvt;
import android.app.Activity;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.os.Bundle;
import android.view.View;
import android.widget.TextView;
import android.widget.Toast;
public class ThreadViewTestActivity extends Activity {
Thread t;
Splash splash;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
splash = new Splash(this);
t = new Thread(splash);
t.start();
splash.setTextow("OA");
try { Thread.sleep(4000); } catch (InterruptedException e) { }
splash.setTextow("LALA");
}
}
And:
public class Splash implements Runnable {
Activity activity;
final Handler myHandler = new Handler();
public Splash(Activity activity) {
this.activity=activity;
}
@Override
public void run() {
// TODO Auto-generated method stub
}
public synchronized void setTextow(final String textow) {
// Wrap DownloadTask into another Runnable to track the statistics
myHandler.post(new Runnable() {
@Override
public void run() {
TextView t = (TextView)activity.findViewById(R.id.testo);
t.setText(textow);
t.invalidate();
}
});
}
}
Although splash is in other thread, i put a sleep on the main thread, i use the handler to manage UI and everything, it doesn't changes a thing, it only shows the last update.
