（这个问题已得到解答：How make commandButton not fully refresh page? How to use f:ajax?）
我在JSF中使用Ajax遇到了一些问题。我有返回字符串的方法，并且只想在单击按钮时打印此字符串。这个方法使用两个参数，我想用2个inputBox传递给这个方法。这里是我到目前为止提供的代码，但是它还没有完成：
<h:commandButton id="submit" value="Submit">
<f:ajax event="click" />
</h:commandButton>
<h:outputText id="result" value="#{cSVobjectCtrl.getJson(48.866667, 2.33333)}" />
这段代码的问题是在单击按钮之前直接得到字符串。我应该更改什么来使代码按照我想要的方式工作？
更新 1 :
<?xml version="1.0" encoding="UTF-8"?>
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<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:h="http://xmlns.jcp.org/jsf/html"
xmlns:c="http://xmlns.jcp.org/jsp/jstl/core"
xmlns:f="http://xmlns.jcp.org/jsf/core">
<h:head>
<title>JsonValue</title>
<meta name="viewport" content="width=device-width, initial-scale=1.0"/>
<script>
var show = function(){
document.getElementById('result').style.display = 'block';
}
</script>
</h:head>
<h:form>
<h:commandButton id="submit" value="Submit" onclick="show();" >
<f:ajax event="click" render="result"/>
</h:commandButton>
<h:outputText id="result" value="#{cSVobjectCtrl.getJson(48.866667, 2.33333)}"
style="display:'none'"/>
</h:form>
</html>
但是问题仍然存在：在单击按钮之前就显示字符串。
This is the solution that have worked for me:
JSF Page
<h:commandButton id="submit" value="Submit">
<f:ajax event="click" render="resultGroup" listener="#{cSVobjectCtrl.doRender}"/>
</h:commandButton>
<h:panelGroup id = "resultGroup" layout="block" >
<h:panelGroup rendered="#{cSVobjectCtrl.rendered}">
<h:outputText id="result" value="#{cSVobjectCtrl.getJson(48.866667, 2.33333)}}" />
</h:panelGroup>
</h:panelGroup>
Backing Bean
@ManagedBean
@ViewScoped // this is important
public class CSVobjectCtrl{
private boolean rendered = false;
public boolean isRendered() {
return rendered;
}
public void setRendered(boolean rendered) {
this.rendered = rendered;
}
public void doRender(AjaxBehaviorEvent event){
rendered = true;
}
}
On the side, in an ajax event you have to explicitly specify which component to refresh / render (if you wont nothing is):
render - Evaluates to Collection. The clientIds of components that will participate in the "render" portion of the Request Processing Lifecycle. If a literal is specified the identifiers must be space delimited. Any of the keywords "@this", "@form", "@all", "@none" may be specified in the identifier list. If not specified, the default value of "@none" is assumed. For example, @this clientIdOne clientIdTwo.