从文件夹中的图片循环播放图像幻灯片时出错

Question

我正在尝试通过循环遍历预定义文件夹中的所有图像来更改图像控件 .picture 属性来创建图像幻灯片

C:\图片

我正在使用的代码：

    Public pixpaths As Collection
    Public pix_path As String
    Public pixnum As Integer
    Public fs As YtoFileSearch
    Public k As Integer

    Public Sub Image_set()
    Set pixpaths = New Collection
    pix_path = "C:\Images"
    Set fs = New YtoFileSearch
    With fs
      .NewSearch
      .LookIn = pix_path
      .fileName = "*.jpg"
      If fs.Execute() > 0 Then
        For k = 1 To .FoundFiles.Count
          pixpaths.Add Item:=.FoundFiles(k)
        Next k
      Else
        MsgBox "No files found!"
        DoCmd.OpenForm "Fr_Sketchpad"    ' If no images found in folder the set image from another form 'Sketchpad' image control
        Forms!Fr_Sketchpad.Visible = False
        Forms!Fr_Main!imgPixHolder.Picture = "" 'Forms!Fr_Sketchpad!Img_Std.Picture   Was getting another error here so commented this
        pixnum = 0
        Exit Sub
      End If
    End With
    'load first pix
    Forms!Fr_Main.imgPixHolder.Picture = pixpaths(1)
    pixnum = 1
    End Sub

    Public Sub Image_loop()
          If pixnum = pixpaths.Count Then
          pixnum = 1
        ElseIf pixnum = 0 Then
            Exit Sub
        Else
          pixnum = pixnum + 1
          Forms!Fr_Main!imgPixHolder.Picture = pixpaths(pixnum)
        End If
    End Sub

    Private Sub Form_Open(Cancel As Integer)
     Call Image_set
    End Sub

    Private Sub Form_Timer()
     Call Image_loop
    End Sub

Image_Set()、Image_loop() 和变量在一个模块中，在 Form_open 和 Form_timer 事件中调用 该代码在一个循环周期内运行良好，但在下一个循环周期内显示错误：

错误 91 对象变量或未设置块变量

开

If pixnum = pixpaths.Count Then

在调试模式下，我检查 pixnum 的值为 0

[更新] 类模块 YtoFileSearch

    Option Compare Database
Option Explicit

' How this is not another proof that doing VBA is a bad idea?
' Nevertheless, we'll try to make the scripts relying on Application.FileSearch works again.

' The interface of this YtoFileSearch class aims to stick to the original
' Application.FileSearch class interface.
' Cf is https://msdn.microsoft.com/en-us/library/office/aa219847(v=office.11).aspx

' For now it do not handle recursive search and only search for files.
' More precisely the following filters are not implemented:
' * SearchSubFolders
' * MatchTextExactly
' * FileType
' If that's something you need, please create an issue so we have a look at it.

' Our class attributes.
Private pDirectoryPath As String
Private pFileNameFilter As String
Private pFoundFiles As Collection

' Set the directory in which we will search.
Public Property Let LookIn(directoryPath As String)
    pDirectoryPath = directoryPath
End Property

' Allow to filter by file name.
Public Property Let fileName(fileName As String)
    pFileNameFilter = fileName
End Property

'Property to get all the found files.
Public Property Get FoundFiles() As Collection
    Set FoundFiles = pFoundFiles
End Property

' Reset the FileSearch object for a new search.
Public Sub NewSearch()
    'Reset the found files object.
    Set pFoundFiles = New Collection
    ' and the search criterions.
    pDirectoryPath = ""
    pFileNameFilter = ""
End Sub

' Launch the search and return the number of occurrences.
Public Function Execute() As Long
    'Lance la recherche
    doSearch

    Execute = pFoundFiles.Count
End Function

' Do the nasty work here.
Private Sub doSearch()
    Dim directoryPath As String
    Dim currentFile As String
    Dim filter As String

    directoryPath = pDirectoryPath
    If InStr(Len(pDirectoryPath), pDirectoryPath, "\") = 0 Then
        directoryPath = directoryPath & "\"
    End If

    ' If no directory is specified, abort the search.
    If Len(directoryPath) = 0 Then
        Exit Sub
    End If

    ' Check that directoryPath is a valid directory path.
    ' http://*.com/questions/15480389/excel-vba-check-if-directory-exists-error
    If Dir(directoryPath, vbDirectory) = "" Then
        Debug.Print "Directory " & directoryPath & " does not exists"
        Exit Sub
    Else
        If (GetAttr(directoryPath) And vbDirectory) <> vbDirectory Then
            Debug.Print directoryPath & " is not a directory"
            Exit Sub
        End If
    End If

    ' We rely on the Dir() function for the search.
    ' cf https://msdn.microsoft.com/fr-fr/library/dk008ty4(v=vs.90).aspx

    ' Create the filter used with the Dir() function.
    filter = directoryPath

    If Len(pFileNameFilter) > 0 Then
        ' Add the file name filter.
        filter = filter & "*" & pFileNameFilter & "*"
    End If

    ' Start to search.
    currentFile = Dir(filter)
    Do While currentFile <> ""
        ' Use bitwise comparison to make sure currentFile is not a directory.
        If (GetAttr(directoryPath & currentFile) And vbDirectory) <> vbDirectory Then
            ' Add the entry to the list of found files.
            pFoundFiles.Add directoryPath & currentFile
        End If
        ' Get next entry.
        currentFile = Dir()
    Loop
End Sub

请指教如何解决！

Answer 1

我必须在这里回答您对我提出的评论问题。这可能无法解决您的问题，但它可能会帮助您找到它，特别是如果错误来自您按照 @dbmitch 的建议在另一个函数中设置 pixpaths = nothing。

您可以像使用 pixpath 一样引用 Image_Set 中的 .FoundFiles，该集合由 .Execute 函数中的 doSearch 子填充，因此以下代码应该可以正常工作。此外，除非您在另一个模块中使用您的参数，否则您可能需要考虑像我在这里所做的那样将它们设为私有。

Private pix_path As String
Private pixnum As Integer
Private fs As YtoFileSearch

Public Sub Image_set()
    pix_path = "C:\Images"
    Set fs = New YtoFileSearch

    With fs
        .NewSearch
        .LookIn = pix_path
        .fileName = "*.jpg"

        If fs.Execute() > 0 Then
            'load first pix
            Forms!Fr_Main.imgPixHolder.Picture = .FoundFiles(1)
            pixnum = 1
        Else
            MsgBox "No files found!"
            DoCmd.OpenForm "Fr_Sketchpad"    ' If no images found in folder the set image from another form 'Sketchpad' image control
            Forms!Fr_Sketchpad.Visible = False
            Forms!Fr_Main!imgPixHolder.Picture = "" 
            'Forms!Fr_Sketchpad!Img_Std.Picture   Was getting another error here so commented this
            pixnum = 0
        End If
    End With
End Sub

Public Sub Image_loop()
    With fs
        If pixnum = .FoundFiles.Count Then
            pixnum = 1
        ElseIf pixnum <> 0 Then
            pixnum = pixnum + 1
            Forms!Fr_Main!imgPixHolder.Picture = .FoundFiles(pixnum)
        End If
    End With
End Sub