从事件处理程序中显示GWT对话框

Question

当我捕获一个异常时，我试图显示一个GWT对话框事件处理程序。对话框不显示。我已经确认了这件事调用处理程序是因为

Window.alert("some msg") 

显示。当我在View对象的事件处理程序外部创建对话框时，它确实会显示。我假设对话框无法访问当前显示。有办法把这个显示出来吗?

下面是一个代码片段:

eventBus.addHandler(ProcessingExceptionEvent.TYPE, new ProcessingExceptionEventHandler() {
    public void onProcessingException(ProcessingExceptionEvent event) {
        // Window.alert("some msg");
        final WiseAlertPanel errorAlert = new WiseAlertPanel("ERROR MESSAGE: " + event.getMessage());
        errorAlert.autoPositionAndShow();
    }
});
public class WiseAlertPanel extends DialogBox {
    VerticalPanel vpPopupl = new VerticalPanel();
    public WiseAlertPanel(String text) {
        setGlassEnabled(true);
        Button button = new Button("Close");
        button.addClickHandler(new ClickHandler() {
            public void onClick(ClickEvent event) {
                WiseAlertPanel.this.hide();
            }
        });
        HorizontalPanel hPanel = new HorizontalPanel();
        hPanel.setHorizontalAlignment(HasHorizontalAlignment.ALIGN_RIGHT);
        hPanel.add(button);
        TextArea label = new TextArea();
        label.setText(text);
        label.setReadOnly(true);
        label.setVisibleLines(5);
        vpPopupl.add(label);
        vpPopupl.add(hPanel);
        setWidget(vpPopupl);
    }
    public void autoPositionAndShow() {
        setPopupPositionAndShow(new PopupPanel.PositionCallback() {
            public void setPosition(int offsetWidth, int offsetHeight) {
                int left = (Window.getClientWidth() - offsetWidth) / 3;
                int top = (Window.getClientHeight() - offsetHeight) / 3;
                WiseAlertPanel.this.setPopupPosition(left, top);
            }
        });
    }

Answer 1

看起来你刚刚在内存中创建了对话框"WiseAlertPanel errorAlert"。

尝试像下面这样调用"autoPositionAndShow"中的show方法

public void autoPositionAndShow() {
    setPopupPositionAndShow(new PopupPanel.PositionCallback() {
        public void setPosition(int offsetWidth, int offsetHeight) {
            int left = (Window.getClientWidth() - offsetWidth) / 3;
            int top = (Window.getClientHeight() - offsetHeight) / 3;
            WiseAlertPanel.this.setPopupPosition(left, top);
            show();
        }
    });
}

参考GWT对话框show()