.net DataVisualisition.Charting.Chart区域类型图表打印为PDF时不是纯色

当我将使用DataVisualistion.Charting.chart类生成的面积类型图表打印到PDF时，会引入一些奇怪的线条，这些线条不是原始图像的一部分。我怎样才能摆脱这些

当转换为PDF或XPS时，所有打印输出上似乎都有这些行。到目前为止，我已经尝试过CutePDF、Postscript->Adobe、XPS打印机

考虑下面的代码，它可以粘贴到一个新表单中，以便快速重新创建

    Imports System.Windows.Forms.DataVisualization.Charting

    Public Class Form1
        Friend WithEvents Chart1 As System.Windows.Forms.DataVisualization.Charting.Chart
        Friend WithEvents Button1 As System.Windows.Forms.Button

        Private Sub IC()
            Me.Button1 = New System.Windows.Forms.Button()
            Dim ChartArea1 As System.Windows.Forms.DataVisualization.Charting.ChartArea = New System.Windows.Forms.DataVisualization.Charting.ChartArea()
            Dim Legend1 As System.Windows.Forms.DataVisualization.Charting.Legend = New System.Windows.Forms.DataVisualization.Charting.Legend()
            Dim Series1 As System.Windows.Forms.DataVisualization.Charting.Series = New System.Windows.Forms.DataVisualization.Charting.Series()
            Dim Series2 As System.Windows.Forms.DataVisualization.Charting.Series = New System.Windows.Forms.DataVisualization.Charting.Series()
            Me.Chart1 = New System.Windows.Forms.DataVisualization.Charting.Chart()

            CType(Me.Chart1, System.ComponentModel.ISupportInitialize).BeginInit()

            Me.Chart1.Anchor = CType((((System.Windows.Forms.AnchorStyles.Top Or System.Windows.Forms.AnchorStyles.Bottom) _
        Or System.Windows.Forms.AnchorStyles.Left) _
        Or System.Windows.Forms.AnchorStyles.Right), System.Windows.Forms.AnchorStyles)
            ChartArea1.Name = "ChartArea1"
            Me.Chart1.ChartAreas.Add(ChartArea1)
            Legend1.Name = "Legend1"
            Me.Chart1.Legends.Add(Legend1)
            Me.Chart1.Location = New System.Drawing.Point(12, 12)
            Me.Chart1.Name = "Chart1"
            Series1.ChartArea = "ChartArea1"
            Series1.ChartType = System.Windows.Forms.DataVisualization.Charting.SeriesChartType.StackedArea
            Series1.Legend = "Legend1"
            Series1.Name = "Series1"
            Series2.ChartArea = "ChartArea1"
            Series2.ChartType = System.Windows.Forms.DataVisualization.Charting.SeriesChartType.StackedArea
            Series2.Legend = "Legend1"
            Series2.Name = "Series2"
            Me.Chart1.Series.Add(Series1)
            Me.Chart1.Series.Add(Series2)
            Me.Chart1.Size = New System.Drawing.Size(553, 343)
            Me.Chart1.TabIndex = 0
            Me.Chart1.Text = "Chart1"

            Me.Button1.Anchor = CType((System.Windows.Forms.AnchorStyles.Top Or System.Windows.Forms.AnchorStyles.Right), System.Windows.Forms.AnchorStyles)
            Me.Button1.FlatStyle = System.Windows.Forms.FlatStyle.Flat
            Me.Button1.Location = New System.Drawing.Point(571, 118)
            Me.Button1.Name = "Button1"
            Me.Button1.Size = New System.Drawing.Size(127, 47)
            Me.Button1.TabIndex = 2
            Me.Button1.Text = "Print"
            Me.Button1.UseVisualStyleBackColor = True

            Me.AutoScaleDimensions = New System.Drawing.SizeF(8.0!, 16.0!)
            Me.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font
            Me.ClientSize = New System.Drawing.Size(710, 367)
            Me.Controls.Add(Me.Chart1)
            Me.Controls.Add(Me.Button1)
            Me.Name = "Form1"
            Me.Text = "Form1"
            CType(Me.Chart1, System.ComponentModel.ISupportInitialize).EndInit()

        End Sub

        Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
            IC()

            Dim generator As New Random
            GenData(generator, Me.Chart1.Series(0))
            GenData(generator, Me.Chart1.Series(1))

        End Sub

        Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
            Dim PD As New PrintDialog
            Dim OK As Boolean = PD.ShowDialog()

            If OK Then
                Me.Chart1.Printing.PrintDocument.PrinterSettings = PD.PrinterSettings
                Me.Chart1.Printing.PrintDocument.Print()
            End If

        End Sub

        Function GenData(ByRef generator As Random, ByRef S As Series)

            For I As Integer = 1 To 30
                Dim randomValue As Integer
                randomValue = generator.Next(10, 100)

                Dim dp As New DataPoint
                dp.XValue = I
                dp.YValues = {randomValue}

                S.Points.Add(dp)
            Next

            Return S
        End Function
    End Class