VB.NET基于排序对Excel列进行排名

Question

Okay, I fought through a good amount of this and have gotten to the point where I can sort my arrays. What I need to do now is take the following code and sort the elements in descending order instead of ascending order. I don't know how to do that with the two arguments in the code:

Dim Cols(3) As Int16
Cols(0) = ColumnNumber + 1
Cols(1) = ColumnNumber + 2
Cols(2) = ColumnNumber + 3
Cols(3) = ColumnNumber + 4

Dim Vals(3) As Double
Vals(0) = xlsWorkSheet.Cells(r, ColumnNumber + 1).value
Vals(1) = xlsWorkSheet.Cells(r, ColumnNumber + 2).value
Vals(2) = xlsWorkSheet.Cells(r, ColumnNumber + 3).value
Vals(3) = xlsWorkSheet.Cells(r, ColumnNumber + 4).value

Array.Sort(Vals, Cols)

Answer 1

If I understand your question correctly, you can implement a descending sort order by reversing the sort results.

You should be able to provide an IComparer instance that reverses the sort order.

Public Class myReverserClass
    Implements IComparer

    ' Calls CaseInsensitiveComparer.Compare with the parameters reversed.
    Function Compare(x As [Object], y As [Object]) As Integer _
        Implements IComparer.Compare
        Return New CaseInsensitiveComparer().Compare(y, x)
    End Function 'IComparer.Compare

End Class 'myReverserClass

Perform the reverse sort like so:

Dim myComparer = New myReverserClass()
Array.Sort(Vals, Cols, myComparer)

There's an example on MSDN that does this: http://msdn.microsoft.com/en-us/library/system.array.sort(v=vs.71).aspx