Gwt 使复合小部件可拖动的问题

我对gwt n dnd比较陌生。。我已经创建了一个复合小部件。。当我试图使复合小部件的对象可拖动时，它会抛出一个异常 “dragHandle必须实现HasMouseDownHandlers、HasMouseHandlers、HasMouseMoveHandlers和HasMouseOutHandlers才能拖动”我是否遗漏了一些非常重要的东西

谢谢，

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sindhu

您可以这样实现它们：

public class MyWidget extends Composite implements HasAllMouseHandlers, HasClickHandlers {

...

      public HandlerRegistration addClickHandler(ClickHandler handler) {
        return addDomHandler(handler, ClickEvent.getType());
      }

      public HandlerRegistration addMouseDownHandler(MouseDownHandler handler) {
          return addDomHandler(handler, MouseDownEvent.getType());
      }

      public HandlerRegistration addMouseMoveHandler(MouseMoveHandler handler) {
        return addDomHandler(handler, MouseMoveEvent.getType());
      }

      public HandlerRegistration addMouseOutHandler(MouseOutHandler handler) {
        return addDomHandler(handler, MouseOutEvent.getType());
      }

      public HandlerRegistration addMouseOverHandler(MouseOverHandler handler) {
        return addDomHandler(handler, MouseOverEvent.getType());
      }

      public HandlerRegistration addMouseUpHandler(MouseUpHandler handler) {
        return addDomHandler(handler, MouseUpEvent.getType());
      }

      public HandlerRegistration addMouseWheelHandler(MouseWheelHandler handler) {
        return addDomHandler(handler, MouseWheelEvent.getType());
      }

}

要使小部件d'n'd正常工作，请参见此