如何允许用户在WPF中向UI控件添加注释?

嗯,我可能会用一个 adorner :

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

我将让您调整注释的位置和实际外观,但您可以理解。这对我有用 UIElement,包括自定义控件。

这是一个即兴的回答,基于我对装饰师所做的其他工作。上面的代码可以编译,也可以不编译。我没有提供编辑注释的方法,但是您可以通过删除“Me.ishitsetvisible=False”行并在装饰器中处理MouseUp事件来轻松编辑注释。