javascript - Wicket:当 Form.MultiPart(true) 时如何显示 Javascript 对话框

Question

当我尝试在 Wicket 中上传文件时出现以下异常:

"ERROR org.apache.wicket.RequestCycle.logRuntimeException(RequestCycle.java:1529) - ServletRequest does not contain multipart content. One possible solution is to explicitly call Form.setMultipart(true), Wicket tries its best to auto-detect multipart forms but there are certain situation where it cannot.
java.lang.IllegalStateException: ServletRequest does not contain multipart content. One possible solution is to explicitly call Form.setMultipart(true), Wicket tries its best to auto-detect multipart forms but there are certain situation where it cannot.
at org.apache.wicket.protocol.http.servlet.MultipartServletWebRequest.<init>(MultipartServletWebRequest.java:113)..."

但是，当我设置 form.MultiPart(true) 时，我无法使用以下方法获取 Javascript 对话框:

target.appendJavascript("Some Message");

有人知道在 Form.Multipart(true) 时如何使用 Javascript 吗？

谢谢!

Answer 1

如果你想调用警告对话框作为对 ajax 请求的响应，你可以使用 appendJavascript() 方法(参数是 javascript 代码，而不是简单的字符串，就像你的代码一样发布):

target.appendJavaScript("alert('Some message');");

如果您想在页面加载时调用警报，您可以使用一种行为:

add(new AbstractBehavior() { // or Behavior, on Wicket 1.5
    @Override
    public void renderHead(Component component, IHeaderResponse response) {
        response.renderOnLoadJavaScript("alert('Some message');");
    }
});

也可以使用标签，并直接渲染到 <script> 标签。请记住调用 setEscapeModelStrings(false):

add(new Label("alert", "alert('Some message');").setEscapeModelStrings(false));

和

<script type="text/javascript" wicket:id="alert"></script>