vb.net图表动态更新数组

Question

我有一个计算图形的数组，并绘制图形的另一个子。 有两个线程用于计算（getArrayForGraph（）），另一个用于绘图图形。

现在我希望图形沿边阵列更新函数绘图，因为数组很长（10 000 000），使得整个过程非常缓慢。

我如何开始更新图表，只要点可用于图表。或者哪个是解决性能问题的最佳途径。

Sub getArrayForGraph() 

    Dim time As Single = 0, finalTime As Single = 0 

    Dim timeinterval As Decimal 'function calulates values in picoseconds 
    Dim timeforGraph() As Long 
    ReDim timeforGraph(TotalSample - 1) 

    For index = 0 To TotalSample - 1 
     If index = 0 Then 
      finalTime = time 
     Else 
      finalTime += timeinterval 
     End If 
     timeforGraph(index) = Math.Round(finalTime, 3) 
    Next 
End Sub 

Sub plotGraph() 

    Chart1.Series("series1").Points.DataBindXY(timeforGraph, bufferDMv) 
     'bufferAMV is array calculated from another for loop 
end sub 

Answer 1

下面是一个完整的例子。它使用BackgroundWorker来执行工作，该工作向UI发送信号以进行更新。它也汇总数据。我选择只显示2000点，因为1. MSChart不能处理很多点，2.我的显示器只有1920像素宽，所以没有必要尝试显示更多。此示例将为每5k（10M/2k）点绘制1点，即x：最新时间，y：平均值。如果你愿意的话，你也可以选择平均时间，但这种情节会更加平庸。

它不包括您的具体变量，因为有一些缺少的信息。但你应该明白它是如何工作的并使其在你的环境中工作

Public Class Form1 

    Private worker As System.ComponentModel.BackgroundWorker 

    Private chartX As New List(Of Long)() 
    Private chartY As New List(Of Long)() 

    ' settings for demo 
    Private count As Long = 10000000 
    Private numberOfGroups As Long = 2000 
    Private groupSize As Long = count/numberOfGroups 

    Private Sub doWork(sender As Object, e As System.ComponentModel.DoWorkEventArgs) 
     ' holds chunk of data to be grouped 
     Dim temp As New List(Of Tuple(Of Long, Long))() 
     For i As Long = 1 To count 
      ' generate some scientific data! 
      temp.Add(New Tuple(Of Long, Long)(i, Convert.ToInt64(i * Math.Sin(Math.PI * i/count) * Math.Sin(i)))) 
      ' make this happen 10 times 
      If i Mod count/10 = 0 Then 
       ' group the time and data into same groupings 
       Dim aggregate = 
        temp. 
        Select(Function(d, index) New Tuple(Of Integer, Tuple(Of Long, Long))(index, d)). 
        GroupBy(Function(d) Math.Floor(d.Item1/groupSize)) 
       ' take the latest time 
       Dim xAggregate = 
        aggregate. 
        Select(Function(a) a.Max(Function(b) b.Item2.Item1)). 
        ToArray() 
       ' take the average data 
       Dim yAggregate = 
        aggregate. 
        Select(Function(a) Convert.ToInt64(a.Average(Function(b) b.Item2.Item2))). 
        ToArray() 
       ' clear temp data 
       temp.Clear() 
       ' -- calling resetChartData() here would make the chart display only the currently processed data 
       ' -- might be useful if you were displaying data from an oscilloscope for instance 
       ' resetChartData() 
       ' add the aggregate data to the chart source data 
       chartX.AddRange(xAggregate) 
       chartY.AddRange(yAggregate) 
       ' report progress (initiate charting) 
       DirectCast(sender, System.ComponentModel.BackgroundWorker).ReportProgress(Convert.ToInt32(100 * i/count)) 
      End If 
     Next 
    End Sub 

    Private Sub progressChanged(sender As Object, e As System.ComponentModel.ProgressChangedEventArgs) 
     ' ui thread runs here. 
     ' perform minimal ui operations as not to slow down ui thread 
     ' added a progress bar, nice to see 
     ProgressBar1.Value = e.ProgressPercentage 
     ' databind the data 
     Chart1.Series("Series1").Points.DataBindXY(chartX, chartY) 
    End Sub 

    Private Sub resetChartData() 
     chartX.Clear() 
     chartY.Clear() 
    End Sub 

    Private Sub runWorkerCompleted(sender As Object, e As System.ComponentModel.RunWorkerCompletedEventArgs) 
     Button1.Enabled = True 
    End Sub 

    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click 
     ' to prevent double clicks 
     Button1.Enabled = False 
     worker = New System.ComponentModel.BackgroundWorker() 
     AddHandler worker.DoWork, AddressOf doWork 
     AddHandler worker.ProgressChanged, AddressOf progressChanged 
     AddHandler worker.RunWorkerCompleted, AddressOf runWorkerCompleted 
     worker.WorkerReportsProgress = True 
     ' do work on background thread 
     worker.RunWorkerAsync() 
    End Sub 

    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load 
     ' set up chart 
     Chart1.Series.Add("Series1") 
     Chart1.Series.Single().MarkerStyle = DataVisualization.Charting.MarkerStyle.None 
     Chart1.Series.Single().ChartType = DataVisualization.Charting.SeriesChartType.FastLine 
     Chart1.Legends.Clear() 
    End Sub 

End Class