Question

在dropdownBox中我有页面列表。当我选择一个时，我想去那个页面。

我该如何实施？我应该添加此代码，但我不知道该怎么做 onUpdate 。我没有找到任何方法来更改页面

new AjaxFormComponentUpdatingBehavior() {

  private static final long serialVersionUID = 1L;

  @Override
  protected void onUpdate(AjaxRequestTarget target) {
  }
}

更新：

我尝试第一次回复时出现异常：

29 Jun 2012 10:07:01,772 ERROR [1215661@qtp-28488784-5] org.apache.wicket.DefaultExceptionMapper : Unexpected error occurred
org.apache.wicket.WicketRuntimeException: Method onRequest of interface org.apache.wicket.behavior.IBehaviorListener targeted at cz.isvs.reg.rob.monitor.web.BasePage$1 {event='onchange'} on component [DropDownChoice [Component id = vyjimkyPage]] threw an exception
    at org.apache.wicket.RequestListenerInterface.internalInvoke(RequestListenerInterface.java:270)
    at org.apache.wicket.RequestListenerInterface.invoke(RequestListenerInterface.java:241)
    at org.apache.wicket.request.handler.ListenerInterfaceRequestHandler.invokeListener(ListenerInterfaceRequestHandler.java:255)
    at org.apache.wicket.request.handler.ListenerInterfaceRequestHandler.respond(ListenerInterfaceRequestHandler.java:234)
    at org.apache.wicket.request.cycle.RequestCycle$HandlerExecutor.respond(RequestCycle.java:784)
    at org.apache.wicket.request.RequestHandlerStack.execute(RequestHandlerStack.java:64)
    at org.apache.wicket.request.cycle.RequestCycle.execute(RequestCycle.java:255)
    at org.apache.wicket.request.cycle.RequestCycle.processRequest(RequestCycle.java:212)
    at org.apache.wicket.request.cycle.RequestCycle.processRequestAndDetach(RequestCycle.java:283)
    at org.apache.wicket.protocol.http.WicketFilter.processRequest(WicketFilter.java:188)
    at org.apache.wicket.protocol.http.WicketFilter.doFilter(WicketFilter.java:244)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:388)
    at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
    at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
    at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765)
    at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:440)
    at org.mortbay.jetty.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:230)
    at org.mortbay.jetty.handler.HandlerCollection.handle(HandlerCollection.java:114)
    at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
    at org.mortbay.jetty.Server.handle(Server.java:326)
    at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
    at org.mortbay.jetty.HttpConnection$RequestHandler.content(HttpConnection.java:943)
    at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:756)
    at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:218)
    at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
    at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:410)
    at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582)
Caused by: java.lang.reflect.InvocationTargetException
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:616)
    at org.apache.wicket.RequestListenerInterface.internalInvoke(RequestListenerInterface.java:260)
    ... 27 more
Caused by: java.lang.IllegalStateException: Attempt to set model object on null model of component: vyjimkyPage
    at org.apache.wicket.Component.setDefaultModelObject(Component.java:3054)
    at org.apache.wicket.markup.html.form.FormComponent.setModelObject(FormComponent.java:1498)
    at org.apache.wicket.markup.html.form.FormComponent.updateModel(FormComponent.java:1059)
    at org.apache.wicket.ajax.form.AjaxFormComponentUpdatingBehavior.onEvent(AjaxFormComponentUpdatingBehavior.java:154)
    at org.apache.wicket.ajax.AjaxEventBehavior.respond(AjaxEventBehavior.java:184)
    at org.apache.wicket.ajax.AbstractDefaultAjaxBehavior.onRequest(AbstractDefaultAjaxBehavior.java:369)
    ... 32 more

Answer 1

你可以做这样的事情

  protected void onUpdate(AjaxRequestTarget target){
   target.prependJavaScript("window.location.href='"+urlFor(new YourPage())+'");
  }

它会更改浏览器的网址，从而重定向。

Answer 2

AbstractSingleSelectChoice 组件（ DropDownChoice 的父级）无法使用 AjaxFormComponentUpdatingBehavior 。类javadoc将您引用到 AjaxFormChoiceComponentUpdatingBehavior ：

注意：此行为不适用于选择或组使用AjaxFormChoiceComponentUpdatingBehavior。

如果您使用AjaxFormChoiceComponentUpdatingBehavior，那么您应该使用模型，因为它将执行字段转换，验证和推送到模型...请记住，您不关心值的ID，可以简单地提供一个你以后从未读过的空模型。

最后，在Wicket中，您可以执行重定向，通过抛出 RedirectException （一个需要 Page 类和可选 PageParameters ）或 RedirectToUrlException ，它需要一个字符串url：

throw new RedirectToUrlException("http://www.supercoolwebsite.com/supercoolexternalpage");

VS

throw new RedirectException(SuperCoolWicketPage.class);

如何在wicket dropDownBox中选择项目时更改页面

2 个答案: