问题
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?
回答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.
来源:https://stackoverflow.com/questions/35703653/pageradapter-return-blank-always