WPF工具提示绑定未更新

大家下午好,

我创建工具提示对象的单个全局实例。我已经绑定了其中的控件,我的应用程序设置了工具提示的datacontext。我可以手动显示和隐藏工具提示只是罚款。当我第一次将鼠标悬停在一个对象上时,它会完美地拾取绑定的数据,效果非常好。当我移到另一个控件上时,工具提示datacontext会更改,但显示的数据永远不会重新加载。

我尝试实现一个属性更改事件,并在绑定到的对象中使用INotifyPropertyChanged接口。wpf工具提示似乎没有侦听事件。

我尝试将绑定模式设置为单向(这是一个仅显示的工具提示)。

// build the tooltip window.
System.Windows.Controls.Image img = new System.Windows.Controls.Image();
img.Width = 50;
img.Height = 60;

// bind the image
System.Windows.Data.Binding imageBinding = new System.Windows.Data.Binding("PatientImage.Data");
imageBinding.Mode = System.Windows.Data.BindingMode.OneWay;
imageBinding.Source = bed;
img.SetBinding(System.Windows.Controls.Image.SourceProperty, imageBinding);

// wrap image in a border
System.Windows.Controls.Border brdr = new System.Windows.Controls.Border();
brdr.BorderBrush = System.Windows.Media.Brushes.Blue;
brdr.Margin = new System.Windows.Thickness(6);
brdr.Child = img;

System.Windows.Controls.WrapPanel wp = new System.Windows.Controls.WrapPanel();

System.Windows.Controls.TextBlock tb = new System.Windows.Controls.TextBlock();
tb.Background = System.Windows.Media.Brushes.LightBlue;
tb.Foreground = System.Windows.Media.Brushes.Blue;

// bind the text block
System.Windows.Data.Binding textBlockBinding = new System.Windows.Data.Binding("TooltipText");
textBlockBinding.Mode = System.Windows.Data.BindingMode.OneWay;
textBlockBinding.Source = bed;
tb.SetBinding(System.Windows.Controls.TextBlock.TextProperty, textBlockBinding);

wp.Children.Add(brdr);
wp.Children.Add(tb);

bedTooltip = new System.Windows.Controls.ToolTip();
bedTooltip.Content = wp;