Question

如何级联列表，如果用户更改selectedCategory列表中的选择，则应更新selectedTo列表。

这是我的代码：

<h:selectOneMenu id="selectedCategory" value="#{converterBean.selectedCategory}">
  <f:ajax execute="selectedCategory" render="selectedFrom"/>
  <f:selectItems value="#{converterBean.categories}"/>
</h:selectOneMenu>
<h:selectOneListbox id="selectedFrom" value="#{converterBean.selectedFrom}" size="5">
  <f:selectItems value="#{converterBean.fromList}"/>
  <f:ajax execute="selectedCategory selectedFrom" render="selectedTo"/>
</h:selectOneListbox>
<h:selectOneListbox id="selectedTo" value="#{converterBean.selectedTo}" size="5">
  <f:selectItems value="#{converterBean.toList}"/>
</h:selectOneListbox>

我注意到它更新了selectedFrom列表，但没有进一步级联到selectTo列表。

根据建议尝试渲染selectedFrom和selectedTo进行类别选择，从页面发布的请求是：

POST http://localhost:8081/converter_web/faces/converter.xhtml HTTP/1.1
Accept: */*
Faces-Request: partial/ajax
Content-Type: application/x-www-form-urlencoded;charset=UTF-8
Referer: http://localhost:8081/converter_web/
Accept-Language: en-us
Accept-Encoding: gzip, deflate
User-Agent: Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; Trident/5.0)
Host: localhost:8081
Content-Length: 1253
Connection: Keep-Alive
Pragma: no-cache
Cookie: JSESSIONID=DDDEA598A60CC468763C36B536513B41

converter_form=converter_form&converter_form%3AselectedCategory=temperature&converter_form%3AselectedFrom=mm&converter_form%3AselectedTo=cm&converter_form%3Avalue=0.0&javax.faces.ViewState=b%2BArKl5NJujWibUQzHf3dUG2JlT%2Bnq7KygA2%2FXpXXscCouBr5xT9Br%2BmoP78%2FvuPAYG%2Bi7Q0jFEKGqJpFgRo%2BDU4ZV251yac84pu3bZ71V9j%2BHvRPMkWw82S8q0v2p1jmn3msPXxvKrQQ1oVpr7pGBPXc2faQGXHW55Md%2BKSkspIgCxXx3x3T6NDaJ1%2BGTEFkyb1DE%2BdoQHQ4EjqV3jEC5mq56OlsHgEmkQ8TVCQM%2FPmAfUBWiQEHqBYzohXNfFpO3kfdrKjeTrq648UtGPYU88VJ9mtIOptYEfwFKN9y%2FG9MOBKEfRZ9XlJz2bPt1zmATIg3iRT1W7YVtmHq7e9g%2FUxsM82duMxFUWhoFPHfrFk4tt48LFH29Hk60y3eeFxqtg7g1JxPD1aQrLN9sxBduS53nFWObCms1YU40uvMT2yjX0kp4wM8YwqT2jTFDtLHcVBide1RGTnzFGzjOrbCJ8rIEmWfPa1yUMkXRBBsgpKWFIl0ueBQiCT%2BDoD9UXlNOQGS%2F5tIdP%2BVTO%2FkWiBo5X99SpKwKY8%2B2pqzJKDrPRXIwci52Wi%2Fo%2Fw%2B0TkpnVrtDaDl7w2eYjmq7bYZFRDjWy3Jtgc5V1DUF%2BhX3Bfiq7l%2Fq5YL4DYx0NBI2esfJ0LTFCqXu8aCk%2BWOPOWnOCSGA5Y9EGUXgzV6q%2Fp%2FFWa8Kj8E%2FeoB380eFwXAEiyyRGv&javax.faces.source=converter_form%3AselectedCategory&javax.faces.partial.event=change&javax.faces.partial.execute=converter_form%3AselectedCategory&javax.faces.partial.render=converter_form%3AselectedFrom%20converter_form%3AselectedTo&javax.faces.behavior.event=valueChange&javax.faces.partial.ajax=true

我们希望只发送selectedCategory，但是它会在ajax调用中发送所有表单字段。它虽然调用getCategories（），getFromList（），getToList（），但是当它调用getToList时，它使用category = temperature和from = mm。 from = mm是POST请求中传递的内容，如selectedFrom = mm。

此致

米滕。

Answer 1

更改此内容：

  <f:ajax execute="selectedCategory" render="selectedFrom"/>

对此：

  <f:ajax execute="selectedCategory" render="selectedFrom selectedTo"/>

Answer 2

我添加了一个如下所示的ajax监听器，因此表明正在调用类别更改，以便getFromList将selectedFrom设置为列表中的新项而不是一个被发布的项。然后getToList将找到正确的类别，并从单元查询其列表。

<f:ajax execute="selectedCategory" render="selectedFrom"></f:ajax>

到

<f:ajax listener="#{converterBean.categoryChanged}" execute="selectedCategory" render="selectedFrom selectedTo"></f:ajax>

jsf级联列表

2 个答案: