如何在转出GWT中的当前视图（onUnLoad）之前设置先前的值？

Question

我已经存储了值onLoad，之后我更改了widget属性，再次卸载之前我想设置以前存储的值，我该怎么办？ widget.addAttachHandler（EventHandler）对我有帮助吗？

Answer 1

只需简单地design your own widget使用事件监听器。在自定义窗口小部件类中，覆盖加载和卸载方法。

// This method is called when a widget is attached to the browser's document
  @Override
  protected void onLoad() {
    setEventListener(inputElem, this);
    // ... 
  }  


  // This method is called when a widget is detached from the browser's document 
  @Override   protected void onUnload() {
    // Clear out the inputElem's event listener (breaking the circular
    // reference between it and the widget); avoid memory leaks
    setEventListener(inputElem, null);
    // ...
  }