GWT-在运行时隐藏或显示一个DIV

如果使用回调机制,则必须在回调函数中进行。

例如,如果您使用的是GWT的请求生成器,则必须在收到请求回调的响应中执行此操作:

   public ModelClass() {
      isAdmin();
   }

   private void isAdmin() {
        RequestBuilder builder = new RequestBuilder(
                RequestBuilder.GET, webserviceurl);
        try {
            request = builder.sendRequest(null, new RequestCallback() {

                public void onResponseReceived(Request request, 
                        Response response) {
                    int code = response.getStatusCode();

                    if(code >= 400) {
                        Window.alert(response.getStatusText());
                        return;
                    }

                    if(code == 200)  {
                         // if admin is logged in
                        // hide your div
                    }
                }

                public void onError(Request request, Throwable exception) {
                   Window.alert("Error checking admin status");
                }

            });
        }catch(RequestException re) {
            Window.alert("Error checking admin status");
        }
    }