02-02 06:03:08.470: E/AndroidRuntime(3898): Caused by: android.view.ViewRootImpl$CalledFromWrongThreadException: Only the original thread that created a view hierarchy can touch its views.
UI작업은 메인스레드를 통해서만 하세요
runOnUiThread(new Runnable() {
@Override
public void run() {
ev.setText("abc");
}
});