title: ClassCastException android.view.viewgroup.$layoutParam
body: <pre><code> TextView txt=new TextView(productlist.this);
              txt.setText(author.get(groupPosition));
              TextView txt1=new TextView(productlist.this);
              txt1.setText(price.get(groupPosition));
              txt.setLayoutParams(new LayoutParams(70, LayoutParams.WRAP_CONTENT));  
              txt1.setLayoutParams(new LayoutParams(70,LayoutParams.WRAP_CONTENT));
              LinearLayout ll=new LinearLayout(productlist.this);
              ll.setOrientation(LinearLayout.HORIZONTAL);
              ll.setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT));  
             // ll.setGravity(Gravity.CENTER);  
              ll.addView(txt);  
              ll.addView(txt1);  
  
              return ll;
  </code></pre>
  
  <p>hi, this is the code snippet for a group view in expandable <code>ListView</code> which gives error:</p>
  
  <blockquote>
    <p>java.lang.ClassCastException android.view.viewgroup.$layoutParam</p>
  </blockquote>