如何解决 UnmapViewOfFile 错误 487？

Question

不确定我应该在哪里做这个，但我发布这个问题是为了节省一些人的时间。我已经找到了答案。如果这不是最好的地方，请告诉我在哪里可以做到这一点。

这是在 UnmapViewOfFile 行之后创建错误 487：

Option Explicit

Private Const PAGE_READWRITE As Long = &H4
Private Const FILE_MAP_WRITE As Long = &H2
Private Const GENERIC_READ = &H80000000
Private Const GENERIC_WRITE = &H40000000
Private Const OPEN_ALWAYS = 4
Private Const FILE_ATTRIBUTE_NORMAL = &H80

'http://www.cadsharp.com/docs/Win32API_PtrSafe.txt

 Declare Function CreateFile Lib "kernel32" Alias "CreateFileA" (ByVal lpFileName As String, _
    ByVal dwDesiredAccess As Long, ByVal dwShareMode As Long, _
    ByVal lpSecurityAttributes As Long, ByVal dwCreationDisposition As Long, _
    ByVal dwFlagsAndAttributes As Long, ByVal hTemplateFile As Long) As Long

 Declare Function CreateFileMapping Lib "kernel32.dll" Alias "CreateFileMappingA" ( _
    ByVal hFile As Long, _
    ByVal lpFileMappigAttributes As Long, _
    ByVal flProtect As Long, _
    ByVal dwMaximumSizeHigh As Long, _
    ByVal dwMaximumSizeLow As Long, _
    ByVal lpName As String) As Long

 Declare Function MapViewOfFile Lib "kernel32.dll" ( _
    ByVal hFileMappingObject As Long, _
    ByVal dwDesiredAccess As Long, _
    ByVal dwFileOffsetHigh As Long, _
    ByVal dwFileOffsetLow As Long, _
    ByVal dwNumberOfBytesToMap As Long) As Long

 Declare Sub CopyMemory Lib "kernel32" Alias _
    "RtlMoveMemory" (Destination As Any, Source As Any, _
    ByVal Length As Long)

 Declare Function CloseHandle Lib "kernel32.dll" ( _
    ByVal hObject As Long) As Long

 Declare Function UnmapViewOfFile Lib "kernel32.dll" ( _
    ByRef lpBaseAddress As Any) As Long


Public hMMF As Long
Public pMemFile As Long

Sub IntoMemoryFileOutOfMemoryFile()
Err.Clear
    Dim sFile As String
    Dim hFile As Long
     Dim bBytes As Variant
    sFile = "C:\test1.txt"
Debug.Print Err.LastDllError
    'https://msdn.microsoft.com/en-us/library/windows/desktop/aa363858%28v=vs.85%29.aspx
    hFile = CreateFile(sFile, GENERIC_READ Or GENERIC_WRITE, 0, 0, OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, 0)
Debug.Print Err.LastDllError
    'https://msdn.microsoft.com/en-us/library/windows/desktop/aa366537%28v=vs.85%29.aspx

    hMMF = CreateFileMapping(hFile, 0, PAGE_READWRITE, 0, 1000000, "MyMemoryMappedFilex")
Debug.Print Err.LastDllError
    'https://msdn.microsoft.com/en-us/library/windows/desktop/aa366761%28v=vs.85%29.aspx
    pMemFile = MapViewOfFile(hMMF, FILE_MAP_WRITE, 0, 0, 1000000)

Debug.Print Err.LastDllError
    UnmapViewOfFile pMemFile '< - produced error 487
Debug.Print Err.LastDllError
    CloseHandle hMMF
Debug.Print Err.LastDllError
    CloseHandle hFile
Debug.Print Err.LastDllError

End Sub

Answer 1

更改此行：

 Declare Function UnmapViewOfFile Lib "kernel32.dll" ( _
    ByRef lpBaseAddress As Any) As Long

到...

 Declare Function UnmapViewOfFile Lib "kernel32.dll" ( _
    ByVal lpBaseAddress As Any) As Long

刚刚将 ByRef 更改为 ByVal。

如何解决 UnmapViewOfFile 错误 487？

how to solve UnmapViewOfFile error 487?

vba

excel

memory-mapped-files