公共字符串不是从select元素设置的,而是从输入框设置的

我觉得我的大脑要爆炸了。请帮忙。

我有一个apex:inputText组件,其值为{!searchString},表示它在我的自定义控制器上的公共字符串。

奇怪的是{!searchString}值是由knowledge:articlelist组件设置和读取的。

注意:为了简单起见,我从控制器中删除了currentPagenumber计算,我看不出它与当前问题有什么关系。此外,我使用的是标准HTML select元素,与apex selectlist组件相反,因为knowledge:categorylist不能嵌套在selectlist中。

public with sharing class KeywordSearchController {

 //Page Size
 private Static Final Integer PAGE_NUMBER = 5;

 //Search String used in ArticleList tag
 public String groupCategory { get; set; }
 public String searchstring  { get; set; }


 public KeywordSearchController() {
  String qryString = 'SELECT Id, title, UrlName, 
  LastPublishedDate,LastModifiedById FROM KnowledgeArticleVersion WHERE 
  (PublishStatus = \'online\' and Language = \'en_US\')';
  List<KnowledgeArticleVersion> articleList= Database.query(qryString);
  maxSize = articleList.size() ;
  }

<apex:page showHeader="false" standardStyleSheets="false" controller="KeywordSearchController">

<apex:form>

 <select id="groupSelect" value="{!groupCategory}">
  <knowledge:categoryList categoryVar="category" categoryGroup="Group" rootCategory="All" level="-1">
   <option value="Group:{!category.name}">{!category.label}</option>
  </knowledge:categoryList>
 </select>

 <div class="field is-grouped">
  <p class="control is-expanded has-icons-left">
   <apex:inputText styleClass="input is-medium" value="{!searchstring}"  />
    <span class="icon is-left">
     <i class="fa fa-search"></i>
    </span>
  </p>

 <p class="control">
  <apex:commandButton value="Search" id="submitButton" styleClass="button is-primary is-medium"  reRender="theSearchResults"/>
 </p>
 </div>
</apex:form>

<apex:form >
 <apex:messages />
 <apex:pageBlock title=""> 
 <apex:panelGroup id="theSearchResults" >
 <apex:panelGrid width="100%">
 <table class="table is-striped is-narrow">
 <thead>
 <tr>
  <th>Title</th>
  <th>Article Type</th>
  <th>Summary</th>
 </tr>
 </thead>
<knowledge:articleList articleVar="article" categories="{!groupCategory}" 
 pageNumber="{!currentPageNumber}" Keyword="{!searchstring}" 
 hasMoreVar="false" pageSize="5">
 <tbody>
 <tr>
  <td>
   <apex:outputLink target="" value="{!URLFOR($Action.KnowledgeArticle.View, article.id,['popup' = 'false'])}">{!article.title}</apex:outputLink>
  </td>
  <td><apex:outputText >{!article.articleTypeLabel}</apex:outputText></td>
  <td><apex:outputText >{!article.abstract}</apex:outputText></td>
 </tr>
 </tbody>
 </knowledge:articleList>
 </table>
 </apex:panelGrid> 
</apex:panelGroup>
</apex:pageBlock>
</apex:form>