java - 无法在层次结构中的指定点插入节点[GWT]

Question

我创建了这样的类

public class FinalizeEvalutionReportPanel extends VerticalPanel{

    //other code...

    public class PopupPanel extends DialogBox
    {
        public PopupPanel() {
            this.setStyleName("gwt-DialogBoxNew");
            this.setText(WorkFlowUtil.getPropertyValue(propertyKeys.showAgreement));
            this.setWidth(StringUtil.getWidthByGivenPercentage(30)+"px");
            this.add(this);
            this.center();
            addHandler();
        }
        private void addHandler() {
            final DialogBox box=this;
            giveFeedbackBtn.addClickHandler(new ClickHandler() {

                @Override
                public void onClick(ClickEvent event) {
                    box.hide();
                }
            });
        }
    }

}

我尝试在单击按钮时从其他类(class)调用它。

showAgreementBtn.addClickHandler(new ClickHandler() {

        @Override
        public void onClick(ClickEvent event) {
        new FinalizeEvalutionReportPanel().showPopUp();//this give Java Script error

        }
    });

我收到此错误...

com.google.gwt.core.client.JavaScriptException: (NS_ERROR_DOM_HIERARCHY_REQUEST_ERR) @com.google.gwt.dom.client.Node::appendChild(Lcom/google/gwt/dom/client/Node;)([JavaScript object(7280)]): Node cannot be inserted at the specified point in the hierarchy

Answer 1

问题可能出在下面一行:

this.add(this);

您无法添加组件本身。