嗯。我可能会用一个装饰器来做这个:
Imports System.Windows
Imports System.Windows.Documents
Imports System.Windows.Media
Public Class Annotation
Inherits Adorner
Private _fill As Brush
Private _pen As Pen
Private _text As FormattedText
Private _annotationText as String
Public Sub New(ByVal adornedElement As UIElement, ByVal annotationText as String)
MyBase.New(adornedElement)
_annotationText = annotationText
_fill = New SolidColorBrush(Color.FromArgb(&H33, &HB0, &HC4, &HDE))
_fill.Freeze()
_pen = New Pen(Brushes.LightSteelBlue, 3.0)
_pen.Freeze()
_text = New FormattedText(_annotationText, Globalization.CultureInfo.InvariantCulture, FlowDirection.LeftToRight, New Typeface("Verdana"), 11.0, Brushes.Black)
Me.IsHitTestVisible = False
End Sub
Protected Overrides Sub OnRender(ByVal drawingContext As DrawingContext)
MyBase.OnRender(drawingContext)
Dim adornedRect As New Rect(MyBase.AdornedElement.RenderSize)
drawingContext.DrawRectangle(_fill, _pen, adornedRect)
drawingContext.DrawText(_text, New Point(0,0))
End Sub
End Class
然后您可以通过以下方式使用它:
Private Sub AddAnnotation(ByVal uie As UIElement, ByVal annotationText as String)
Dim annotation = New Annotation(uie)
Dim adornerLayer = AdornerLayer.GetAdornerLayer(uie, annotationText)
adornerLayer.Add(annotation)
End Sub
我会让你调整注释的位置和实际外观,但你明白了。这适用于任何UIElement,包括自定义控件。
这是基于我与 Adorners 所做的其他一些工作的即兴回答。上面的代码可能编译也可能不编译。我没有提供编辑注释的方法,但您可以通过删除“Me.IsHitTestVisible = False”行并在装饰器中处理 MouseUp 事件来轻松完成此操作。