VB6读写含Unicode文件名的二进制文件 现有代码报错如何解决

问题原因 #

VB6 原生内置的 Open、Get、Put 等文件操作语句是基于ANSI编码实现的，解析文件名时遇到Unicode特殊字符会出现编码转换失败，因此你在打开带特殊符号的文件名时会触发报错。WMI查询返回的文件名本身是Unicode格式，问题完全出在文件读写环节的实现。

解决方案 #

方案1：调用系统Unicode版复制API（最简实现，无需自行处理读写逻辑） #

直接调用kernel32提供的CopyFileWAPI，原生支持Unicode文件名，只需少量改动即可兼容：

1. 首先在代码模块顶部声明API：

Private Declare Function CopyFileW Lib "kernel32.dll" (ByVal lpExistingFileName As Long, ByVal lpNewFileName As Long, ByVal bFailIfExists As Long) As Long

2. 重写你的cpyBIN函数：

Function cpyBIN(cpFilename As String) As Boolean
    ' StrPtr将VB字符串转为Unicode指针传入API，第三个参数0表示备份文件已存在时直接覆盖
    cpyBIN = CopyFileW(StrPtr(cpFilename), StrPtr(cpFilename & "Backup"), 0) <> 0
End Function

无需修改你现有窗体的调用逻辑，直接替换即可正常支持Unicode文件名。

方案2：使用Unicode版文件操作API自行实现二进制读写 #

如果你需要在读写文件过程中做额外处理（比如加密、修改内容等），可以用CreateFileW系列API替换原生文件操作语句：

1. 模块顶部声明依赖API和常量：

Private Declare Function CreateFileW Lib "kernel32.dll" (ByVal lpFileName As Long, 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
Private Declare Function ReadFile Lib "kernel32.dll" (ByVal hFile As Long, lpBuffer As Any, ByVal nNumberOfBytesToRead As Long, lpNumberOfBytesRead As Long, Optional ByVal lpOverlapped As Long = 0) As Long
Private Declare Function WriteFile Lib "kernel32.dll" (ByVal hFile As Long, lpBuffer As Any, ByVal nNumberOfBytesToWrite As Long, lpNumberOfBytesWritten As Long, Optional ByVal lpOverlapped As Long = 0) As Long
Private Declare Function GetFileSize Lib "kernel32.dll" (ByVal hFile As Long, lpFileSizeHigh As Long) As Long
Private Declare Function CloseHandle Lib "kernel32.dll" (ByVal hObject As Long) As Long

Private Const GENERIC_READ = &H80000000
Private Const GENERIC_WRITE = &H40000000
Private Const OPEN_EXISTING = 3
Private Const CREATE_ALWAYS = 2

2. 重写cpyBIN函数：

Function cpyBIN(cpFilename As String) As Boolean
    Dim hSrcFile As Long, hDstFile As Long
    Dim fileSize As Long, bytesRead As Long, bytesWritten As Long
    Dim litefile() As Byte
    
    ' 打开源文件
    hSrcFile = CreateFileW(StrPtr(cpFilename), GENERIC_READ, 0, 0, OPEN_EXISTING, 0, 0)
    If hSrcFile = -1 Then Exit Function
    
    ' 获取文件大小
    fileSize = GetFileSize(hSrcFile, 0)
    If fileSize <= 0 Then
        CloseHandle hSrcFile
        Exit Function
    End If
    ReDim litefile(fileSize - 1)
    
    ' 读取源文件内容
    Call ReadFile(hSrcFile, litefile(0), fileSize, bytesRead, 0)
    Call CloseHandle(hSrcFile)
    If bytesRead <> fileSize Then Exit Function
    
    ' 创建备份文件
    hDstFile = CreateFileW(StrPtr(cpFilename & "Backup"), GENERIC_WRITE, 0, 0, CREATE_ALWAYS, 0, 0)
    If hDstFile = -1 Then Exit Function
    
    ' 写入备份内容
    Call WriteFile(hDstFile, litefile(0), fileSize, bytesWritten, 0)
    Call CloseHandle(hDstFile)
    
    cpyBIN = (bytesWritten = fileSize)
End Function

附加说明 #

你原有窗体代码中调用cpyBIN (objfile.Name)的写法建议调整为Call cpyBIN(objfile.Name)，避免VB隐式按值传参导致的异常。

内容的提问来源于stack exchange，提问作者enddie onskynet