public FullWindowPopup()
        {
            _contentControl = new ContentControl()
            {
                HorizontalContentAlignment = HorizontalAlignment.Stretch,
                VerticalContentAlignment = VerticalAlignment.Stretch
            };

            _popup = new Popup()
            {
                Child = _contentControl
            };
            var binding = new Binding()
            {
                Source = this,
                Path = new PropertyPath(nameof(IsOpen)),
                Mode = BindingMode.TwoWay
            };
            _popup.SetBinding(Popup.IsOpenProperty, binding);

            Action keepPopupSize = () =>
            {
                Window.Current.SizeChanged += delegate
                {
                    ReSize();
                };
                ReSize();
            };

            var app = Bootstrapper.Current;
            if (app != null && app.IsInConstructing)
            {
                // 应用程序的 App 类继承自 Bootstrapper,并且当前处于 App 类的构造函数中,将保持 Popup 大小的方法放至构造函数执行完成后再执行。
                app._waitForConstructedActions.Add(() =>
                {
                    keepPopupSize.Invoke();
                    return Task.FromResult<object>(null);
                });
            }
            else
            {
                keepPopupSize.Invoke();
            }
        }