Excel VBA Array（）函數導致類型不匹配？

Question

我創建了以下函數來查找文件並在找不到文件時給出錯誤：

Public Function checkFileExistence(arrFileNames() As String, Optional bShowErrMsg As Boolean = False) As Boolean
' This function looks for every file name in arrFileNames and returns True if all exist else False
' Optional: bShowErrMsg = True will tell the user which file was missing with a MsgBox
Dim file As Variant

For Each file In arrFileNames
    If Len(Dir(file, vbNormal)) = 0 Then
        checkFileExistence = False
        If bShowErrMsg = True Then MsgBox (file & " was not found.")
        Exit Function
    End If
Next file
checkFileExistence = True
End Function

當我去調用它時，我得到了類型不匹配錯誤。 使用預定義的數組以及嘗試使用Array（）函數時會發生這種情況：

.
Dim filesToFind(1 To 3) As String
filesToFind(1) = "image.png"
filesToFind(2) = "test.png"
filesToFind(3) = "test.fred"

Debug.Print checkFileExistence(filesToFind, True)
Debug.Print checkFileExistence(Array("image.png", "test.png", "test.fred"), True)

如果arrFileNames（）是Variant，也會發生這種情況。 我究竟做錯了什么？

Answer 1

Array不返回類型化數組（例如String() ）。

更改您的簽名以取代Variant ：

Public Function checkFileExistence(arrFileNames As Variant, Optional bShowErrMsg As Boolean = False) As Boolean

您可以使用IsArray函數始終驗證您正在查看實際數組：

    If Not IsArray(arrFileNames) Then Err.Raise 5, "CheckFileExistence", "Expected array, but received a " & TypeName(arrFileNames) & "."

另外，我強烈建議將循環更改為For...Next循環。 數組不希望使用For Each進行迭代 - 請參閱此文章 。

For i = LBound(arrFileNames) To UBound(arrFileNames)