为什么第一个随机数总是一样的？

Question

我正在开发一个宏，该宏选择一系列随机的员工 ID 号进行随机测试。我的代码运行良好，除了返回的第一个数字总是相同的。例如，如果我的 ID 号是 1-100，并且我想要 10 个随机数，那么第一个数字将始终为 1，然后是随机数。

作为一项额外的挑战，是否有可能在列表循环完成之前不会选择相同的数字？

这是我正在使用的代码。

Sub Macro1()
   '
   '
   '
'
 Dim CountCells
 Dim RandCount
Dim LastRow
Dim Counter1
Dim Counter2
Worksheets.Add().Name = "Sheet1"
Worksheets("Employee ID#").Select
 Range("a2:A431").Select
Selection.Copy
Worksheets("Sheet1").Select
Selection.PasteSpecial

Worksheets("Sheet1").Select
Range("A1").Select
CountCells = WorksheetFunction.Count(Range("A:A")) 'quantity of random numbers to pick from
If CountCells = 0 Then Exit Sub
On Error Resume Next
Application.DisplayAlerts = False
RandCount = Application.InputBox(Prompt:="How many random numbers do you want?", _
      Title:="Random Numbers Selection", Type:=1)
On Error GoTo 0
Application.DisplayAlerts = True
RandCount = Int(RandCount)
If Int(RandCount) <= 0 Or RandCount = False Then Exit Sub
If RandCount > CountCells Then
    MsgBox "Requested quantity of numbers is greater than quantity of available data"
    Exit Sub
End If


LastRow = Cells(Rows.Count, "A").End(xlUp).Row
'clear working area
Range("B:C").ClearContents
'clear destination area
Range("Sheet2!A:A").ClearContents
'create index for sort use
Range("B1") = 1
Range(Cells(1, 2), Cells(LastRow, 2)).DataSeries , Step:=1
'create random numbers for sort
Range("C1") = "=RAND()"
Range("C1").Copy Range(Cells(1, 3), Cells(LastRow, 3))
'randomly sort data
Range(Cells(1, 1), Cells(LastRow, 3)).Sort Key1:=Range("C1"), Order1:=xlAscending, Header:=xlGuess, _
    Orientation:=xlTopToBottom, DataOption1:=xlSortNormal
'data has been sorted randomly, cells in column A, rows 1 through the quantity desired will be chosen
Counter1 = 1
Counter2 = 1
Do Until Counter1 > RandCount
    If IsNumeric(Cells(Counter2, 1).Value) And Cells(Counter2, 1).Value <> Empty Then
        Range("Sheet2!A" & Counter1) = Cells(Counter2, 1).Value
        Counter1 = Counter1 + 1
        'Selection.ClearContents
    End If
    Counter2 = Counter2 + 1

Loop
'resort data into original order and clear working area
Range(Cells(1, 1), Cells(LastRow, 3)).Sort Key1:=Range("B1"), Order1:=xlAscending, Header:=xlGuess, _
    Orientation:=xlTopToBottom, DataOption1:=xlSortNormal
Range("B:C").ClearContents
Sheets("Sheet2").Select
'Sheets("Sheet2").PrintOut





End Sub

提前感谢您的帮助。

Answer 1

要获得不同的第一个数字，只需在函数开头添加一行 Randomize。

您可以将员工列表加载到一个数组中，然后当一个被选中时，从数组中删除该员工，这样他们就不能再次被选中。

-编辑-

我想出了这段代码，应该对你有用。它将员工 ID#s 加载到一个数组中，因此您不必处理选择和重新排列单元格，这是一个缓慢的操作。然后代码从所有员工的数组中挑选员工，并将他们添加到员工数组中进行检查。然后它从所有员工的数组中删除员工，这样他们就不能再次被选中。一旦代码选择了需要检查的员工人数，它就会将他们写入所需的工作表中。

Sub SelectRandomEntries()

    Dim WSEmp As Worksheet
    Dim WSCheckedEmps As Worksheet
    Dim AllEmps() As Long 'An array to hold the employee numbers
                         'Assuming Column A is an integer employee #
    Dim CheckedEmps() As Long
    Dim FirstRow As Long
    Dim LastRow As Long
    Dim RandCount As Long
    Dim RandEmp As Long
    Dim i As Long

    'Set the worksheets to variables.  Make sure they're set to the appropriate sheets in YOUR workbook.
    Set WSEmp = ThisWorkbook.Worksheets("Employee ID#") 'Sheet with all employees
    Set WSCheckedEmps = ThisWorkbook.Worksheets("Checked Employees") 'Sheet with checked employees
    FirstRow = 1
    LastRow = WSEmp.Cells(WSEmp.Rows.Count, "A").End(xlUp).Row 'Find the last used row in a ColumnA

    Randomize 'Initializes the random number generator.

    'Load the employees into an array
    ReDim AllEmps(FirstRow To LastRow) 'Make the array large enough to hold the employee numbers
    For i = FirstRow To LastRow
        AllEmps(i) = WSEmp.Cells(i, 1).Value
    Next

    'For this example, I sent RandCount to a random number between the first and last entries.
    'Rnd() geneates a random number between 0 and 1 so the rest of line converts it to a usable interger.
    RandCount = Int((LastRow - FirstRow + 1) * Rnd() + FirstRow)
    MsgBox (RandCount & "will be checked")
    ReDim CheckedEmps(1 To RandCount)

    'Check random employees in the array
    For i = 1 To RandCount
        RandEmp = Int((LastRow - FirstRow + 1) * Rnd() + FirstRow) 'pick a random employee to check
        If IsNumeric(AllEmps(RandEmp)) And AllEmps(RandEmp) <> Empty Then 'If the emp# is valid
            CheckedEmps(i) = AllEmps(RandEmp) 'Move the employee to the checked employee list.
            AllEmps(RandEmp) = Empty 'Clear the employee from the full list so they can't get picked again
        Else
            i = i - 1 'If you checked a RandEmp that wasn't suitable, you'll need to check another one.
        End If
    Next

    'Write the employees to the results sheet
    For i = 1 To RandCount
        WSCheckedEmps.Cells(i, 1) = CheckedEmps(i)
    Next i

End Sub

您可能需要添加与您的数据集特别相关的检查（我只是使用了一些随机整数），并且您需要重新实现一种方法，让人们选择检查多少员工。