vb.net – 等待多个BackgroundWorkers完成

我必须使用多个大的二维数组(例如1024 x 128),在我的代码的一部分中,我需要转置一些(最多12个).
该过程需要相当长的时间,我试图尽可能加快速度.知道VB.NET支持多线程我在这里和那里读了不同的源,并且可以在主子例程中提出以下代码：

RunXTransposingThreads(Arr1,Arr2,Arr3,...)

使用BackgroundWorkers作为我的解决方案的一部分：

Private Sub RunXTransposingThreads(ParamArray ArraysToTranspose() As Array)
    Dim x = CInt(ArraysToTranspose.GetLength(0)) - 1
    Dim i As Integer
    For i = 0 To x
        Dim worker As New System.ComponentModel.BackgroundWorker
        AddHandler worker.DoWork,AddressOf RunOneThread
        AddHandler worker.RunWorkerCompleted,AddressOf HandleThreadCompletion
        worker.RunWorkerAsync(ArraysToTranspose(i))
    Next
End Sub

Private Sub RunOneThread(ByVal sender As System.Object,ByVal e As System.ComponentModel.DoWorkEventArgs)
    Dim Transposed(,) As Single = Array.CreateInstance(GetType(Single),0) ' I need this to be like that in order to use other functions later
    Transposed = Transpose2dArray(CType(e.Argument,Single(,)))
    e.Result = Transposed
End Sub

Private Sub HandleThreadCompletion(ByVal sender As Object,ByVal e As System.ComponentModel.RunWorkerCompletedEventArgs)
    Debug.Print("Process complete")
End Sub

Function Transpose2dArray(Of Array)(ByVal inArray As Array(,)) As Array(,)

    Dim x = CInt(inArray.GetLength(1))
    Dim y = CInt(inArray.GetLength(0))
    Dim outArray(x - 1,y - 1) As Array

    For i = 0 To x - 1
        For j = 0 To y - 1
            outArray(i,j) = inArray(j,i)
        Next
    Next

    Transpose2dArray = outArray

End Function

线程似乎有效,因为在执行RunXTransposingThreads后的某个时刻,我在屏幕上看到了一些“Process complete”.问题是：如果我还没有转置数组,如何停止执行main中的代码？

Function RunXTransposingTasks(ParamArray ArraysToTranspose() As Array) As Array
    Dim taskList = New List(Of Task(Of Single(,))) ' our tasks returns Arrays

    For Each arr In ArraysToTranspose
        Dim r = arr
        taskList.Add(Task.Run(Function() Transpose2dArray(r)))
    Next

    Task.WhenAll(taskList) ' wait for all tasks to complete. 
    Return taskList.Select(Function(t) t.Result).ToArray()
End Function

Function Transpose2dArray(inArray As Array) As Single(,)
    Dim x = inArray.GetLength(1) - 1
    Dim y = inArray.GetLength(0) - 1
    Dim outArray(x,y) As Single

    For i = 0 To x
        For j = 0 To y
            outArray(i,i)
        Next
    Next

    Return outArray
End Function

' Usage
' Dim result = RunXTransposingTasks(Arr1,...)