Freemarker For loop

问题

Is their any way to traverse list item based on their rather than one by one? I want to traverse a list of fields in 1,3,5,7,9 and 2,4,6,8 order. I tried using like this

<#list section.field as field>
 <div class="col1">
 ${field.@label}:<input type="text"/></div>
 <#if field_has_next>
 <div class="col2">
   ${field[field_index+1].@label}:<input type="text"/>
 </div>
 </#if>
</#list>

But it gave me error.

回答1:

This is what ?chunk is for (http://freemarker.org/docs/ref_builtins_sequence.html#ref_builtin_chunk):

<#list section.field?chunk(2) as row>
  <#list row as field>
    <div class="col${field_index + 1}">
      ${field.@label}: <input type="text"/>
    </div>
  </#list>
</#list>

Otherwise I don't know what error you get with your solution, but surely there's a bug in it that it displays all fields but the last one twice. You could freely play with the indexes with something like

<#assign fields = section.field>
<#assign idx = 0>
<#list 0..999999 as _>
   <#if idx == fields?size><#break></#if>
   ... even column ...
   <#assign idx = idx + 1>

   <#if idx == fields?size><#break></#if>
   ... odd column ...
   <#assign idx = idx + 1>
</#list>
...

but as you see it doesn't really fit FreeMarker (it's awfully verbose).

来源：https://stackoverflow.com/questions/17723612/freemarker-for-loop