摘要： In the WPF example the Popup and the ToggleButton (the arrow on the right) are bound with the property IsDropDownOpen:在模版里面设置<Popup IsOpen="{TemplateBinding IsDropDownOpen}" ...<ToggleButton IsChecked="{Binding Path=IsDropDownOpen,Mode=TwoWay,RelativeSource={RelativeSource Templ 阅读全文