VBA访问中的全局变量

Question

在页面顶部，在我声明任何函数或子例程之前，我声明了一个公共变量i。 在子例程addRow（）和removeRow（）中，他们可以毫无问题地访问i，但是当我尝试在函数generateIf（s As String，x As Integer）中访问它时，它表示它已脱离上下文。为什么会这样，我该如何解决？

Option Compare Database
Public i As Integer

Private Sub buttonSubmit_Click()
    sql = generateSQL()
End Sub

Private Sub Form_Load()
    i = 0
End Sub

Private Sub buttonCancel0_Click()
    removeRow
End Sub

Private Sub buttonAdd0_Click()
    addRow
End Sub

Private Sub addRow()
    Dim f As Form
    DoCmd.OpenForm "Create_Report"
    Set f = Forms!Create_Report

    If i = 4 Then
        GoTo LastLine
    End If

    i = i + 1
    'Sets next row visible
    f.Controls("cmbNum" & CStr(i)).Visible = True
    f.Controls("cmbMetric" & CStr(i)).Visible = True
    f.Controls("cmbCond" & CStr(i)).Visible = True

LastLine:
End Sub

Private Sub removeRow()
    Dim f As Form
    DoCmd.OpenForm "Create_Report"
    Set f = Forms!Create_Report

    'Sets next row visible
    If i = 0 Then
        GoTo LastLine
    End If
    f.Controls("cmbNum" & CStr(i)).Visible = False
    f.Controls("cmbMetric" & CStr(i)).Visible = False
    f.Controls("cmbCond" & CStr(i)).Visible = False
    i = i - 1

LastLine:
End Sub

Public Function generateSQL() As String
    Dim sql, transform, sel, from, where, groupBy, oderBy, pivot, ifStatement  As String
    transform = "TRANSFORM Count([9_0_result_data].[Current Proposal Status]) AS Expr2"
    from = "FROM 9_0_result_data"
    where = "WHERE ((([9_0_result_data].DayDiff)>=0) AND (([9_0_result_data].[Current Proposal Status])='Funded'))"
    ifStatement = generateIf("", 0, i)
    sel = ""
End Function


Public Function generateIf(s As String, x As Integer) As String
    Dim sql As String
    sql = s

    Dim f As Form
    DoCmd.OpenForm "Create_Report"
    Set f = Forms!Create_Report

    sql = sql & "IIf(DateDiff('" & LCase(Left$(f.Controls("cmbMetric" & CStr(x)).Value, 1)) & "',[" & cmbCompare0.Value & "],[" & cmbCompare1.Value _
            & "])" & f.Controls("cmbCond" & CStr(x)).Value & f.Controls("cmbNum" & CStr(x)).Value & ",'" _
            & f.Controls("cmbNum" & CStr(x)).Value & f.Controls("cmbMetric" & CStr(x)).Value & "',"

    x = x + 1

    If x >= i Then
        sql = sql & "'" & f.Controls("cmbMetric" & CStr(x)).Value & f.Controls("cmbNum" & CStr(x)).Value & "'"
    Else
        sql = generateIf(sql, x)
    End If

    sql = sql & ")"

    'Stupid VBA return values
    generateIf = sql
End Function