java - 如何在 GWT 中退出当前 View (onUnLoad)之前设置先前的值？

Question

我已经在加载时存储了值，之后我更改了小部件属性，并且在卸载之前再次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

就这么简单design your own widget使用事件监听器。并在您的自定义小部件类中使用 ovveride 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);
    // ...
  }