ViewHolder的其他写法

public class ViewHolder {

// I added a generic return type to reduce the casting noise in client code  
@SuppressWarnings("unchecked")  
public static <T extends View> T get(View view, int id) {  
    SparseArray<View> viewHolder = (SparseArray<View>) view.getTag();  
    if (viewHolder == null) {  
        viewHolder = new SparseArray<View>();  
        view.setTag(viewHolder);  
    }  
    View childView = viewHolder.get(id);  
    if (childView == null) {  
        childView = view.findViewById(id);  
        viewHolder.put(id, childView);  
    }  
    return (T) childView;  
}  

}

@Override
public View getView(int position, View convertView, ViewGroup parent) {

if (convertView == null) {  
    convertView = LayoutInflater.from(context)  
      .inflate(R.layout.item, false);  
}  

TextView tv = ViewHolder.get(convertView, R.id.phone);  
tv.setText("测试");  

return convertView;  

}