Android ViewPager zeigt keine Content-Bilder

Question

In meiner App gibt es einen Viewpager, der für die Anzeige einer Reihe von Bildern verwendet wird. Wenn ich die Aktivität starte, zeigt der viewpager jedoch keinen Inhalt an, obwohl ich überprüft habe, dass die Methode getCount() in meiner benutzerdefinierten Adapterklasse 1 den Debugger zurückgibt.

Mein Adapter Layout:

<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:orientation="vertical" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    android:id="@+id/layout_picture" 
    android:clickable="true"> 

<ImageView 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:id ="@+id/iv_picture"/> 
<TextView 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:text="Picture"/> 

</LinearLayout> 

Mein ViewPager Layout:

<android.support.v4.view.ViewPager 
     android:layout_width="match_parent" 
     android:layout_height="wrap_content" 
     android:id="@+id/vp_pictures" 
     android:visibility="visible"/> 

Meine benutzerdefinierte Adapterklasse:

public class PicturePagerAdapter extends PagerAdapter{ 

Context context; 
LayoutInflater inflater; 
ArrayList<Bitmap> data; 
ViewPager pager; 
private boolean deleteEnable; 

public PicturePagerAdapter(Context ctx, ArrayList<Bitmap> data, ViewPager p, boolean delete_enable){ 
    this.context = ctx; 
    this.data = data; 
    this.pager = p; 
    this.deleteEnable = delete_enable; 
} 

@Override 
public int getCount() { 
    return data.size(); 
} 

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

@Override 
public Object instantiateItem(ViewGroup container, final int position) { 

    ImageView picture; 
    LinearLayout layout_picture; 

    inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE); 
    View v = inflater.inflate(R.layout.pager_adapter_pictures, null); 
    picture = (ImageView)v.findViewById(R.id.iv_picture); 
    layout_picture = (LinearLayout)v.findViewById(R.id.layout_picture); 
    BitmapDrawable drawable = new BitmapDrawable(data.get(position)); 
    picture.setImageDrawable(drawable); 
    if(deleteEnable) { 
     layout_picture.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View v) { 
       AlertDialog.Builder b = new AlertDialog.Builder(context); 
       b.setTitle(context.getResources().getString(R.string.actions_title)); 
       b.setMessage(context.getResources().getString(R.string.actions_picture)); 
       b.setNegativeButton(context.getResources().getString(R.string.delete_picture), new DialogInterface.OnClickListener() { 
        @Override 
        public void onClick(DialogInterface dialog, int which) { 
         removeBitmapAt(pager, position); 
        } 
       }); 
      } 
     }); 
    } 
    container.addView(v); 
    return v; 
} 

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

public void addBitmap(Bitmap map){ 
    pager.setAdapter (null); 
    this.data.add(map); 
    pager.setAdapter(this); 
} 

public void removeBitmapAt(ViewPager pager, int index){ 
    pager.setAdapter (null); 
    this.data.remove(index); 
    pager.setAdapter (this); 
} 

Und schließlich ist dies, wie ich Setup die viewpager in meiner Tätigkeit :

this.picturePager = (ViewPager) findViewById(R.id.vp_pictures); 
this.pagerAdapter = new PicturePagerAdapter(context, activityController.getCurrentBook().getPictures(), picturePager, false); 
this.picturePager.setAdapter(this.pagerAdapter); 
Toast.makeText(this, "Size:"+picturePager.getAdapter().getCount(),Toast.LENGTH_LONG).show(); 

Toast() im obigen Code wird 1 zurückgeben, was korrekt ist. Da der ViewPager in meiner Aktivität nicht angezeigt wird, helfen Sie bitte.

Answer 1

Set android:layout_height="match_parent" in viewpager xml.