Android中ListView Item布局优化技巧

private static final int TYPE_LEFT = 0; 
private static final int TYPE_CENTER = 1; 
private static final int TYPE_RIGHT = 2; 
@Override 
public int getViewTypeCount() { 
 return 3; 
} 
//假如我们的数据列表是list，里面的Bean有一个属性（type）是表明这个item应该使用哪种布局的。 
@Override 
public int getItemViewType(int position) { 
 return list.get(position).type; 
} 
//然后在我们的getView方法就可以这样了 
@Override 
public View getView(int position, View convertView, ViewGroup parent) { 
 int type = getItemViewType(position); 
 ViewHoldLeft holdLeft; 
 ViewHoldCenter holdCenter; 
 ViewHoldRight holdRight; 
 if (convertView == null) { 
  switch(type) { 
   case TYPE_LEFT: 
    holdLeft = new ViewHoldLeft(); 
    convertView = xxxxxx//像普通的一样 
    holdLeft.textView = xxxxxx//像普通的一样 
    holdLeft.textView.setText("holdLeft"); 
    convertView.setTag(holdLeft); 
    break; 
   case TYPE_CENTER: 
    holdCenter = new ViewHoldCenter(); 
    convertView = xxxxxx//像普通的一样 
    holdCenter.textView = xxxxxx//像普通的一样 
    holdCenter.textView.setText("holdCenter"); 
    convertView.setTag(holdCenter); 
    break; 
   case TYPE_RIGHT: 
    holdRight = new ViewHoldRight(); 
    convertView = xxxxxx//像普通的一样 
    holdRight.textView = xxxxxx//像普通的一样 
    holdRight.textView.setText("holdRight"); 
    convertView.setTag(holdRight); 
    break; 
   default: 
    break; 
  } 
 } else { 
  switch(type) { 
   case TYPE_LEFT: 
    holdLeft = (ViewHoldLeft)convertView.getTag(); 
    holdLeft.textView.setText("holdLeft"); 
    break; 
   case TYPE_CENTER: 
    holdCenter = (ViewHoldCenter)convertView.getTag(); 
    holdCenter.textView.setText("holdCenter"); 
    break; 
   case TYPE_RIGHT: 
    holdRight = (ViewHoldRight)convertView.getTag(); 
    holdRight.textView.setText("holdRight"); 
    break; 
   default: 
    break; 
  } 
 } 
 return convertView; 
} 
private static class ViewHoldLeft { 
 private TextView textView; 
} 
private static class ViewHoldCenter { 
 private TextView textView; 
} 
private static class ViewHoldRight { 
 private TextView textView; 
}