循环文件夹中的所有文件 (VBA) - 运行时错误 52

如何解决循环文件夹中的所有文件 (VBA) - 运行时错误 52

Option Explicit

Sub AllWorkbooks()
    Dim MyFolder As String
    Dim MyFile As String
    Dim wbk As Workbook
    
Application.ScreenUpdating = False

With Application.FileDialog(msoFileDialogFilePicker)
    .Title = "Please select a folder"
    .Show
    .AllowMultiSelect = False
    If .SelectedItems.Count = 0 Then
        MsgBox "You did not select a folder"
        Exit Sub
    End If
    
    MyFolder = .SelectedItems(1) & "\"
End With

MyFile = Dir(MyFolder)
do while MyFile <> ""
    Set wbk = Workbooks.Open(Filename:=MyFolder & MyFile)
    Sheets(2).Range("A1").Value = "hi!"
    wbk.Close savechanges:=True
    MyFile = Dir
Loop
Application.ScreenUpdating = True
    
    
End Sub

我复制了此视频 https://www.youtube.com/watch?v=J0PeXcAVaUM&t=169s 中的代码。 当我尝试运行此代码时，它显示“运行时错误 52：错误的文件名或编号” 似乎“MyFile = Dir(MyFolder)”有问题。 我该如何解决这个问题？非常感谢！