title: Convert Listview Items into a single Bitmap Image
body: <p>Referenced to this topic: <a href="https://stackoverflow.com/questions/12742343/android-get-screenshot-of-all-listview-items">Android get screenshot of all ListView items</a></p>
  
  <p>I want to do something like that but i have Custom Adapter and it's throw me NullPointerException Error at this code:</p>
  
  <pre><code>childView.measure(MeasureSpec.makeMeasureSpec(_listView.getWidth(),    MeasureSpec.EXACTLY),MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
  </code></pre>
  
  <hr>
  
  <p>My Custom Adapter:</p>
  
  <pre><code>public class InvoiceListAdapter extends BaseAdapter {
  
    ArrayList&lt;Object&gt; _itemList;
    public Activity _context;
    public LayoutInflater _inflater;
    BarCodeGenerator Generator = new BarCodeGenerator();
  
  
    public InvoiceListAdapter(Activity context,ArrayList&lt;Object&gt; itemList)
    {
        super();
        this._context=context;
        this._itemList=itemList;
        this._inflater=(LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
  
    }
  @Override
  public int getCount() {
      // TODO Auto-generated method stub
      return _itemList.size();
  }
  
  @Override
  public Object getItem(int position) {
      // TODO Auto-generated method stub
      return _itemList.get(position);
  }
  
  @Override
  public long getItemId(int position) {
      // TODO Auto-generated method stub
      return 0;
  }
  
  public static class ViewHolder
  {
   TextView ProductName;
   TextView Qnt;
   ImageView Barcode;
   TextView BarcodeFormat;
   Button Del;
  
  }
  
  
  
  @Override
  public View getView(final int position, View convertView, ViewGroup parent) {
  
      ViewHolder holder;
       if(convertView==null)
          {
              holder = new ViewHolder();
              convertView = _inflater.inflate(R.layout.custom_row_view, null);
  
  
              holder.ProductName = (TextView) convertView.findViewById(R.id.txt_CRow_ProdName);
              holder.Qnt = (TextView) convertView.findViewById(R.id.txt_CRow_Qnt);
              holder.Del = (Button) convertView.findViewById(R.id.btn_CRow_Delete);
              holder.Barcode = (ImageView) convertView.findViewById(R.id.Img_CRow_Barcode);
              /*-----------------------------Deleting Item with Button--------------------*/
              holder.Del.setTag(holder);
  
  
              convertView.setTag(holder);
          }
          else
          {
              holder=(ViewHolder)convertView.getTag();
          }
  
          AnItem Item = (AnItem) _itemList.get(position);
  
          holder.ProductName.setText(Item.getProductName());
          holder.Qnt.setText(Item.getQnt());
          holder.Barcode.setImageBitmap(Generator.Generate(Item.getProductName(), BarcodeFormat.valueOf(Item.getBarcode() ),500,200 ) ); 
  
          holder.Del.setOnClickListener(new OnClickListener() {
              @Override
              public void onClick(View v) {
                  Toast.makeText(_context,"Item Deleted!: "+position, Toast.LENGTH_SHORT).show();
  
                  _itemList.remove(position);  
                  notifyDataSetChanged();
  
                  // TODO Auto-generated method stub
  
              }
          });
  
          return convertView;
  
  
  }
  
  }
  </code></pre>
  
  <hr>
  
  <p>My Custom Row:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical"&gt;
  
  &lt;TextView
  android:id="@+id/txt_CRow_ProdName"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:hint="@string/ProductName"
  android:textSize="16sp"
  android:textStyle="bold" /&gt;
  
  &lt;Button
  android:id="@+id/btn_CRow_Delete"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:layout_alignParentRight="true"
  android:layout_centerVertical="true"
  android:focusable="false"
  android:text="@string/Delete"
  android:textSize="12sp"/&gt;
  
  &lt;TextView
  android:id="@+id/txt_CRow_Qnt"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:layout_below="@+id/Img_CRow_Barcode"
  android:hint="@string/Qnt"
  android:textSize="12sp"
  android:textStyle="bold" /&gt;
  
  &lt;ImageView
  android:id="@+id/Img_CRow_Barcode"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:layout_below="@+id/txt_CRow_ProdName"
  android:layout_centerVertical="true"
  android:layout_toLeftOf="@+id/btn_CRow_Delete"
  android:layout_alignParentLeft="true"
   /&gt;
  
  &lt;/RelativeLayout&gt;
  </code></pre>
  
  <p>Thanks for your Help.</p>