select 只读 但能显示下拉菜单
1 <select onfocus="this.defaultIndex=2;" onchange="this.selectedIndex=this.defaultIndex;"> 2 <option value="1">1</option> 3 <option value="2">2</option> 4 <option value="3" selected>3</option> 5 <option value="4">4</option> 6 </select> 7 <select> 8 <option value="1" disabled>1</option> 9 <option value="2" disabled>2</option> 10 <option value="3" selected disabled>3</option> 11 <option value="4" disabled>4</option> 12 </select>