Listview注意事项

1.缓存

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    ViewHolder holder;
    if (convertView == null) {
        convertView = inflater.inflate(R.layout.type_item, null);
        holder = new ViewHolder();
        holder.imageView = (ImageView)convertView.findViewById(R.id.app_icon);
        holder.textView = (TextView)convertView.findViewById(R.id.app_name);
        convertView.setTag(holder);
    } else {
        holder = (ViewHolder)convertView.getTag();
    }
    holder.imageView.setImageResource(R.drawable.index_default_image);
    holder.textView.setText("");
    return convertView;
}

/**
 * ViewHolder
 */
static class ViewHolder {

    ImageView imageView;
    TextView  textView;
}

　　2.Listview的layout属性不要为wrap_content，不然会重复计算高度宽度