asp-classic - 在 ASP/SQL 中创建多级组合框

Question

Table categories:
   id  
   name 
   parent_id    

价值观

       1 - Main Category  - 0,
       2 - Main Category1 - 1,
       3 - Main category2 - 1,
       4 - Subcategory 1  - 2,
       5 - Subcategory 2  - 2
       6 - Main category3 - 1

像这样的组合框

Main Category 
     --> Main Category 1
     -------->SubCategory 1
     -------->SubCategory 2
     --> Main Category 2
     --> Main Category 3

如何 ？？？感谢您的回答！

Answer 1

除非您提交表单，否则您需要使用 javascript。下面给出了一个示例代码

cat1:<input type="checkbox" id="cat1"><br>

cat2:<input type="checkbox" id="cat2"  onChange="fnc('subcat1','subcat2')"><br>
subcat1:<input type="checkbox" id="subcat1" style="visibility:hidden"><br>
subcat2:<input type="checkbox" id="subcat2" style="visibility:hidden"><br>
cat3:<input type="checkbox" id="cat3">

<script type="text/javascript">
function fnc(id1,id2)
{

if(document.getElementById("cat2").checked==true)
{
document.getElementById(id1).style.visibility='visible';
document.getElementById(id2).style.visibility='visible';
}
else
{
document.getElementById(id1).style.visibility='hidden';
document.getElementById(id2).style.visibility='hidden';
}
}
</script>