.net - IO.FileInfo 奇怪的异常 "Illegal characters in path"当有任何非法字符

Question

我收到“路径中的非法字符”异常，但字符串似乎没有任何非法字符。

我该如何解决这个问题？:

Private Sub Button_Send_Click(sender As Object, e As EventArgs) Handles Button_Send.Click

    For Each item As ListViewItem In ListView1.Items

        Clipboard.SetText(item.SubItems(0).Text)
        ' First I copy the text to the clipboard to ensure in Explorer.exe if all is ok and also ifthe file exists... and yes, it exists.
        ' The example text is this:
        ' C:\Electro\Nueva carpeta\Aggresivnes - Dance Or Die.mp3
        ' (without any quotes)


        ' ...But this throws an "not exists":
        If IO.File.Exists(item.SubItems(0).Text) Then MsgBox("exists") Else MsgBox("not exists")


        ' And here throws an exception of "*Illegal characters in path*" :
        Dim File As New IO.FileInfo(item.SubItems(0).Text)

    Next

End Su

UPDATE 2

我在自己的代码中犯了一个错误，没有注意到当没有问题时返回 true 而当问题存在时返回 false，所以我决定删除我的旧更新并编辑这个:

我做了一个函数来(再次)验证文件名转换或字符串变量中的某些内容是否有任何无效字符，遵循@Jim Mischel 回答指示:

#Region " Validate Windows FileName "

    ' [ Validate Windows FileName Function ]
    '
    ' By Elektro H@cker
    '
    ' Examples :
    ' MsgBox(Validate_Windows_FileName("C:\Test.txt"))  ' Result: True
    ' MsgBox(Validate_Windows_FileName("C:\Te|st.txt")) ' Result: False

    Private Function Validate_Windows_FileName(ByRef FileName As String)
        Dim Directory As String = Nothing
        Dim File As String = Nothing

        Try
            Directory = FileName.Substring(0, FileName.LastIndexOf("\")) & "\"
            File = FileName.Split("\").Last
        Catch
            If Directory Is Nothing Then File = FileName
        End Try

        If Directory Is Nothing AndAlso File Is Nothing Then Return False

        If Not Directory Is Nothing Then
            For Each InvalidCharacter As Char In IO.Path.GetInvalidPathChars
                If Directory.Contains(InvalidCharacter) Then
                    ' MsgBox(InvalidCharacter)
                    Return False
                End If
            Next
        End If

        If Not File Is Nothing Then
            For Each InvalidCharacter As Char In IO.Path.GetInvalidFileNameChars
                If File.Contains(InvalidCharacter) Then
                    ' MsgBox(InvalidCharacter)
                    Return False
                End If
            Next
        End If

        Return True ' FileName is valid
    End Function

#End Region

好吧...现在我使用该函数再次确保完整路径/文件名和结果为“false”，这意味着该字符串包含无效字符，而该字符类似于“空格”。

 MsgBox(Validate_Windows_FileName(item.SubItems(0).Text))

我不知道如何解决这个问题。

如果你想看完整的类(class)，这里是:

Public Class Main

    Dim WinAmpTitle As String = String.Empty
    Dim WinAmpFile As String = String.Empty

    Dim Sendto_Path As String

    Dim WithEvents WinAmp_Timer As New Timer With {.Interval = 25, .Enabled = True}

    Private Sub Main_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        ' Nothing to do here at the momento...
    End Sub

    Private Sub WinAmp_Timer_Tick(sender As Object, e As EventArgs) Handles WinAmp_Timer.Tick

        WinAmpTitle = WinAmpInfo.Title
        WinAmpFile = WinAmpInfo.FileName

        If Not TextBox_Title.Text = WinAmpTitle Then TextBox_Title.Text = WinAmpTitle

        If Not TextBox_Filename.Text = WinAmpFile Then TextBox_Filename.Text = WinAmpFile

    End Sub

    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button_Copy.Click
        Dim item = ListView1.Items.Add(WinAmpFile)
        item.SubItems.Add(ComboBox_Sendto.Text)

    End Sub

    Private Sub Button_Send_Click(sender As Object, e As EventArgs) Handles Button_Send.Click

        For Each item As ListViewItem In ListView1.Items


            Clipboard.SetText(item.SubItems(0).Text)
            ' First I copy the text to the clipboard to ensure in Explorer.exe if the file exists... and yes, it exists.
            ' The example text is this:
            ' C:\Electro\Nueva carpeta\Aggresivnes - Dance Or Die.mp3
            ' (without any quotes)


            ' ...But this throws an "not exists":
            If IO.File.Exists(item.SubItems(0).Text) Then MsgBox("exists") Else MsgBox("not exists")

            MsgBox(Validate_Windows_FileName(item.SubItems(0).Text)) ' Result: False (any invalid character)


            ' Here, an exception: "Illegal characters in path" :
            Dim File As New IO.FileInfo(item.SubItems(0).Text)

            ' If item.SubItems(1).Text.ToLower = "electro" Then Sendto_Path = "C:\Electro"
            ' If item.SubItems(1).Text.ToLower = "techno" Then Sendto_Path = "C:\Techno"
            ' If item.SubItems(1).Text.ToLower = "trance" Then Sendto_Path = "C:\Trance"

            'IO.File.Copy(File.FullName, IO.Path.Combine(Sendto_Path, File.Name))

        Next

    End Sub


#Region " Validate Windows FileName "

    ' [ Validate Windows FileName Function ]
    '
    ' By Elektro H@cker
    '
    ' Examples :
    ' MsgBox(Validate_Windows_FileName("C:\Test.txt"))  ' Result: True
    ' MsgBox(Validate_Windows_FileName("C:\Te|st.txt")) ' Result: False

    Private Function Validate_Windows_FileName(ByRef FileName As String)
        Dim Directory As String = Nothing
        Dim File As String = Nothing

        Try
            Directory = FileName.Substring(0, FileName.LastIndexOf("\")) & "\"
            File = FileName.Split("\").Last
        Catch
            If Directory Is Nothing Then File = FileName
        End Try

        If Directory Is Nothing AndAlso File Is Nothing Then Return False

        If Not Directory Is Nothing Then
            For Each InvalidCharacter As Char In IO.Path.GetInvalidPathChars
                If Directory.Contains(InvalidCharacter) Then
                    ' MsgBox(InvalidCharacter)
                    Return False
                End If
            Next
        End If

        If Not File Is Nothing Then
            For Each InvalidCharacter As Char In IO.Path.GetInvalidFileNameChars
                If File.Contains(InvalidCharacter) Then
                    ' MsgBox(InvalidCharacter)
                    Return False
                End If
            Next
        End If

        Return True ' FileName is valid
    End Function

#End Region

End Class

...第二部分(我认为不太重要):

#Region " WinAmp Info "

' [ WinAmp Info Functions ]
'
' // By Elektro H@cker
'
' Examples:
' MsgBox(WinAmpInfo.Title)    ' Result: Artist - Title
' MsgBox(WinAmpInfo.FileName) ' Result: C:\Title.ext

Public Class WinAmpInfo

    Private Const WinampClassName As String = "Winamp v1.x"

    Private Declare Auto Function FindWindow Lib "user32" (ByVal lpClassName As String, ByVal lpWindowName As String) As IntPtr
    Private Declare Auto Function GetWindowText Lib "user32" (ByVal hwnd As IntPtr, ByVal lpString As String, ByVal cch As Integer) As Integer
    Private Declare Function GetWindowThreadProcessId Lib "user32" (ByVal hWnd As Long, ByRef lpdwProcessId As Long) As Long
    Private Declare Function OpenProcess Lib "kernel32" (ByVal dwDesiredAccess As Long, ByVal bInheritHandle As Long, ByVal dwProcessId As Long) As Long
    Private Declare Function SendMessage Lib "user32" Alias "SendMessageA" (ByVal hWnd As Long, ByVal Msg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long
    Private Declare Function ReadProcessMemory Lib "kernel32" (ByVal hProcess As Long, ByVal lpBaseAddress As Long, ByRef lpBuffer As Byte, ByVal nSize As Long, ByRef lpNumberOfBytesRead As Long) As Long
    Private Declare Function CloseHandle Lib "kernel32" (ByVal hObject As Long) As Long

    Public Shared Function Title() As String

        Dim hwnd As IntPtr = FindWindow(WinampClassName, vbNullString)

        Dim lpText As String = String.Empty
        Dim strTitle As String = String.Empty

        Dim intLength As Integer = 0
        Dim intName As Integer = 0
        Dim intLeft As Integer = 0
        Dim intRight As Integer = 0
        Dim intDot As Integer = 0

        If hwnd.Equals(IntPtr.Zero) Then Return "WinAmp is not running"

        lpText = New String(Chr(0), 100)
        intLength = GetWindowText(hwnd, lpText, lpText.Length)

        If (intLength <= 0) _
        OrElse (intLength > lpText.Length) _
        Then Return "Unknown"

        strTitle = lpText.Substring(0, intLength)
        intName = strTitle.IndexOf(" - Winamp")
        intLeft = strTitle.IndexOf("[")
        intRight = strTitle.IndexOf("]")

        If (intName >= 0) _
        AndAlso (intLeft >= 0) _
        AndAlso (intName < intLeft) _
        AndAlso (intRight >= 0) _
        AndAlso (intLeft + 1 < intRight) _
        Then Return strTitle.Substring(intLeft + 1, intRight - intLeft - 1)

        If (strTitle.EndsWith(" - Winamp")) _
        AndAlso (strTitle.Length > " - Winamp".Length) _
        Then strTitle = strTitle.Substring(0, strTitle.Length - " - Winamp".Length)

        intDot = strTitle.IndexOf(".")

        If (intDot > 0) _
        AndAlso (IsNumeric(strTitle.Substring(0, intDot))) _
        Then strTitle = strTitle.Remove(0, intDot + 1)

        Return strTitle.Trim

    End Function

    Public Shared Function FileName() As String

        Dim lp As Long, lpWinamp As Long, iIndex As Long, PID As Long, bRet As Long, dwRead As Long
        Dim Buffer(260) As Byte

        Dim hWndWinamp As IntPtr = FindWindow(WinampClassName, vbNullString)
        If hWndWinamp = 0 Then Return Nothing

        iIndex = SendMessage(hWndWinamp, &H400, 0, 125)

        lp = SendMessage(hWndWinamp, &H400, iIndex, 211)
        If lp = 0 Then Return Nothing

        Call GetWindowThreadProcessId(hWndWinamp, PID)

        lpWinamp = OpenProcess(&H10, 0, PID)
        If lpWinamp = 0 Then Return Nothing

        bRet = ReadProcessMemory(lpWinamp, lp, Buffer(0), 260, dwRead)

        Call CloseHandle(lpWinamp)

        Return System.Text.UnicodeEncoding.Default.GetString(Buffer)

    End Function

End Class

#End Region

UPDATE 3:

我的新尝试......一切都解释清楚了，我得到了一个无效的字符，我不知道为什么......

Private Sub Button_Send_Click(sender As Object, e As EventArgs) Handles Button_Send.Click

    For Each item As ListViewItem In ListView1.Items

        Dim filenameee As String = item.SubItems(0).Text.Trim ' The trim is...fuck, is just 'cause I don't know what more try to get a valid path...)

        Clipboard.SetText(filenameee) ' result: "C:\Test.mp3" (Without any double quote of course)

        ' ...but this launchs an "not exists" msgbox with the filename "C:\Test.mp3":
        If IO.File.Exists(filenameee) Then MsgBox("exists") Else MsgBox("not exists")

        MsgBox(filenameee) ' this showns "C:\Test.mp3" /without double quotes)
        MsgBox("filename is vlaid?:" & Validate_Windows_FileName(filenameee)) ' Result: False (path is invalid) (REALLY!!!!??? WTF)


        ' Here, an exception: "Illegal characters in path" :
        Dim File As New IO.FileInfo(item.SubItems(0).Text) ' (REALLY!!!!???)

    Next

End Sub

UPDATE 4:

照片:

应用本身:

(C:\Test.mp3为filenameee变量文本)

Io.file.exists 证明:

显示filenameee变量内容:

检查文件名是否有效:

显示文件名中假定的非法字符:

(空格？)

异常:

UPDATE 5

我认为真正的问题在于我在第 2 次更新中发布的 winamp 类的“filename()”函数:

Return System.Text.UnicodeEncoding.Default.GetString(Buffer)

因为它似乎返回了一个有效的字符串，正如您在图像中看到的那样，但在“Autos”中似乎是一个大字符串:

如果有人可以帮我解决这个问题...

谢谢。

UPDATE 6:

这是有效的，我想知道是否存在一种方法或其他方法来改进它以避免使用 For 循环:

Dim i As Int32 = 0
For Each by In System.Text.Encoding.Default.GetString(Buffer)
    If by = Nothing Then Exit For 'MsgBox(i)
    i += 1
Next

Return System.Text.Encoding.Default.GetString(Buffer, 0, i)

Answer 1

根据无效路径字符 (GetInvalidPathChars) 和无效文件名字符 (GetInvalidFilenameChars) 检查您的文件名。这应该会告诉您哪些字符不好。

请注意 File.Exists 不会“抛出”任何东西。它返回 false 表示该文件不存在。作为the documentation状态:

The Exists method should not be used for path validation, this method merely checks if the file specified in path exists. Passing an invalid path to Exists returns false. To check whether the path contains any invalid characters, you can call the GetInvalidPathChars method to retrieve the characters that are invalid for the file system. You can also create a regular expression to test the whether the path is valid for your environment.

换句话说，File.Exists 不在乎你传递给它的是不是垃圾。它会告诉您不存在具有该垃圾名称的文件。它不会告诉您您为它指定了错误的路径名。

评论后更新

我不知道你在那里用 ReadProcessMemory 等做什么，但你的问题可能出在这段代码上:

    bRet = ReadProcessMemory(lpWinamp, lp, Buffer(0), 260, dwRead)

    Call CloseHandle(lpWinamp)

    Return System.Text.UnicodeEncoding.Default.GetString(Buffer)

在这里，您将数据读入一个 260 字节的缓冲区，然后创建一个字符串，但您没有告诉 GetString 要使用该缓冲区的多少字节，因此它将使用 (或尝试使用)所有这些。所以你最终会在你的字符串末尾得到各种各样的垃圾(可能)。

此外，我不清楚您是要尝试使用 Unicode 编码还是默认编码。您有 System.Text.UnicodeEncoding.Default。这将为您提供 Default 的编码代码页，这是系统默认的ANSI代码页。如果您想要默认编码，则只需使用 System.Text.Encoding.Default。

假设您需要以 null 结尾的 ANSI 字符串，那么您需要让代码在调用 GetString 之前找到字符串的长度。通过在缓冲区中搜索第一个 0 字节来做到这一点。这会给你长度，然后你可以调用GetString(buffer, 0, length) .

要找到长度，请执行以下操作:

Dim Len as Integer
For Len = 0 to 260
    if Buffer(Len) = 0 Then Exit For
Next
Return System.Text.Encoding.Default.GetString(Buffer, 0, Len)