真ん中にテキストがあるディアガノール分割を使用して、黄色と緑の2色の長方形を描画しようとしています。
問題は、中央のテキストが緑の上にある場合は白になり、黄色の上にある場合は黒になることです。
ここでの例:
黄色、緑、およびテキストを黒または白で描画できますが、テキストをマスキングして目的の効果を得るにはどうすればよいでしょうか?
これまでの私のコードは次のとおりです。
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim colour1Brush As New SolidBrush(Color.Yellow)
Dim colour2Brush As New SolidBrush(Color.Green)
Dim g As Graphics = Me.CreateGraphics
Dim rect As New Rectangle(New Point(50, 50), New Size(100, 50))
With g
'draw the background yellow
.FillRectangle(colour1Brush, rect)
'put in the black text
DrawText(g, rect, "12", Brushes.Black)
'draw the green triangle
Dim triPoints(2) As Point
triPoints(0) = New Point(rect.Left + rect.Width, rect.Top)
triPoints(1) = New Point(rect.Left + rect.Width, rect.Top + rect.Height)
triPoints(2) = New Point(rect.Left, rect.Top + rect.Height)
.FillPolygon(colour2Brush, triPoints)
'now we need white text that doesn't overwrite the existing black text
'?????? DrawText(g, rect, "12", Brushes.White)
End With
End Sub
Private Sub DrawText(ByRef g As Graphics, ByVal rect As Rectangle, ByVal text As String, ByVal brush As Brush)
Dim fnt As New Font("Segoe UI", 8)
Dim textSize As SizeF = g.MeasureString(text, fnt)
Dim x As Integer = CInt(rect.Left + ((rect.Width / 2) - (textSize.Width / 2)))
Dim y As Integer = CInt(rect.Height + ((rect.Height / 2) - (textSize.Height / 2)))
g.DrawString(text, fnt, brush, New Point(x, y))
End Sub