note 13-android progress bar

firstBar.setVisibility(View.VISIBLE);
firstBar.setVisibility(View.GONE);

different type of style:

<ProgressBar
    android:id="@+id/firstBar"
    style="?android:attr/progressBarStyleHorizontal"
    android:layout_width="200dip"
    android:layout_height="wrap_content"
    android:visibility="gone"
    />
<ProgressBar
    android:id="@+id/secondBar"
    style="?android:attr/progressBarStyle"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:visibility="gone"
    />

note the :

"?android:attr/progressBarStyleHorizontal"

 "?android:attr/progressBarStyle"