PagerAdapter return blank always

Question

I'm trying to make an image pager and it looks like I've done it correct according to all the tutorials that I've looked up, but all I get is a blank screen. A breakpoint on the adapter's instantiateItem method tells me that it is being called and all the right information is getting set into the views, and swiping even works, but I still don't see anything. Here is my code

activity_photos.xml

<RelativeLayout> // I'm not including that code, irrelevant.
<android.support.v4.view.ViewPager
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:id="@+id/imagePager"
    android:background="@android:color/black"/>
</RelativeLayout>

viewpager_itemx.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              android:orientation="vertical"
              android:layout_width="match_parent"
              android:layout_height="match_parent">

    <ImageView
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:id="@+id/imageView"/>

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/imageLabel"
        android:textColor="@android:color/white"/>
</LinearLayout>

PhotosActivity.java

    final String[] images = getResources().getStringArray(R.array.tips_images);
    final String[] labels = getResources().getStringArray(R.array.tips_text);

    final ViewPager viewPager = (ViewPager) findViewById(R.id.imagePager);
    final ViewPagerAdapter viewPagerAdapter = new ViewPagerAdapter(PhotoTipsActivity.this, images, labels);

    viewPager.setAdapter(viewPagerAdapter);

and finally, ViewPagerAdapter.java

public class ViewPagerAdapter extends PagerAdapter {

private Context context;
private String[] images;
private String[] labels;

public ViewPagerAdapter(Context context, String[] images, String[] labels) {
    this.context = context;
    this.images = images;
    this.labels = labels;
}

@Override
public int getCount() {
    return images.length;
}

@Override
public boolean isViewFromObject(View view, Object object) {
    return view == object;
}

@Override
public Object instantiateItem(ViewGroup container, int position) {
    final View itemView = LayoutInflater.from(context).inflate(R.layout.viewpager_item, container, false);
    final ImageView imageView = (ImageView) itemView.findViewById(R.id.imageView);
    final TextView imageLabel = (TextView) itemView.findViewById(R.id.imageLabel);

    // Get drawable image.
    final int imageId = context.getResources().getIdentifier(images[position], "drawable", context.getPackageName());

    imageView.setImageResource(imageId);
    imageLabel.setText(labels[position]);

    return itemView;
}

@Override
public void destroyItem(ViewGroup container, int position, Object object) {
    container.removeView(((LinearLayout) object));
}

}

Any blatantly obvious reason why I'm not seeing my images?

Answer 1

The same way destroyItem() needs to remove the view from the container, instantiateItem() needs to add the view to the container.

Just add

    container.addView(itemView);

before returning from instantiateItem() and you'll be in business.