安卓实习期间整理知识点（十五）

View中setTag, getTag的两个已知用处

• ViewHolder， 提高getView效率，与convertView结合使用

// setTagconvertView.setTag(recordViewHodler);...// getTagrecordViewHodler = (RecordViewHodler) convertView.getTag();...class RecordViewHodler {        HexagonImage ivTechnician;        TextView tvTechnicianName;        TextView tvDateTime;        TextView tvDateAddress;        TextView tvTechnicianDistance;        ImageView ivDateSituation;}

• 用在Button中，提高判断效率，常常与SysConstants静态变量结合使用

Button viewButton = new Button(this);Button controllButton = new Button(this);viewButton.setTag(SysConstants.VIEW_OPTION);controllButton.setTag(SysConstant.CONTROLL_OPTION);viewButton.setOnClickListener(this);controllButton.setOnClickListener(this);...public void onClick(View view){    int option = view.getTag();    switch(option){        case SysConstants.VIEW_OPTION:        break;        case SysConstants.CONTROLL_OPTION:        break;        default:        break;    }}

xml，class文件id, 变量名命名规范

// xml idid="@+id/tv_title"// class 变量名private TextView mTvTitle;