使用e.graphics.drawellips绘制表单上的圆圈？

Question

我想在圈子里画圈，我试过了，但有困难。

这是我的密码

Private Sub DrawCircle()
Dim g As Graphics
g = Panel1.CreateGraphics
Dim yellowPen As New Pen(Color.Yellow, 20)
Dim bluePen As New Pen(Color.Blue, 30)
Dim greenPen As New Pen(Color.Green, 20)
Dim skybluePen As New Pen(Color.AliceBlue, 20)
Dim voiletPen As New Pen(Color.Violet, 15)
Dim blackPen As New Pen(Color.Black, 2)

' Draw ellipses
g.DrawEllipse(yellowPen, 260, 180, 10, 10)

g.DrawEllipse(greenPen, 240, 160, 50, 50)

g.DrawEllipse(bluePen, 220, 140, 90, 90)

g.DrawEllipse(greenPen, 200, 120, 130, 130)

g.DrawEllipse(skybluePen, 180, 100, 170, 170)

g.DrawEllipse(blackPen, 180, 100, 170, 170)

g.DrawEllipse(voiletPen, 170, 90, 190, 190)


End Sub

 Private Sub Panel1_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles Panel1.Paint
DrawCircle()
End Sub

它运行良好，但如果有其他选择，因为如果您在这段代码中做了一点改动，所有的事情都会出错，请帮助我解决问题。

Answer 1

也许我没有正确地理解你的观点，我认为你在寻找另一种解决方案。

Private colorForAllCircles As Color
Private ReadOnly rand As New Random

Function RandomColor() As Color
Return Color.FromArgb(rand.Next(0, 256), rand.Next(0, 256), rand.Next(0, 256))
End Function

Private Sub Form1_Paint(ByVal sender As System.Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles MyBase.Paint
Dim centerX, centerY As Integer
Dim cornerX, cornerY As Integer
Dim radius As Integer
Dim greenPen As New Pen(Brushes.Blue)

centerX = 300
centerY = 200
Dim i As Integer
For i = 20To 200 Step 20
  greenPen = New Pen(RandomColor, 20)
  radius = i
  cornerX = centerX - radius / 2
  cornerY = centerY - radius / 2
  e.Graphics.DrawEllipse(greenPen, cornerX, cornerY, radius, radius)

Next

End Sub