由于一些平台对UTF-8的支持不够,导致程序开发上的一些困难,于是查到一些资料,还是很有意义的。发出来参考一下
支持常见的ANSI、UTF-8、UTF-16LE、UTF-16BE这几种编码文本
[code]
Option Explicit
'mTextUTF.bas
'模块:UTF文本文件访问
'作者:zyl910
'版本:1.0
'日期:2006-1-23
'== 说明 ===================================================
'支持Unicode编码的文本文件读写。暂时支持ANSI、UTF-8、UTF-16LE、UTF-16BE这几种编码文本
'== 更新记录 ===============================================
'[V1.0] 2006-1-23
'1.支持最常见的ANSI、UTF-8、UTF-16LE、UTF-16BE这几种编码文本
'## 编译预处理常数 #########################################
'== 全局常数 ===============================================
'IncludeAPILib:引用了API库,此时不需要手动写API声明
'## API ####################################################
#If IncludeAPILib = 0 Then
'== File ===================================================
Private 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
Private Declare Function CloseHandle Lib “kernel32” (ByVal hObject As Long) As Long
Private Declare Function ReadFile Lib “kernel32” (ByVal hFile As Long, lpBuffer As Any, ByVal nNumberOfBytesToRead As Long, lpNumberOfBytesRead As Long, ByVal lpOverlapped As Long) As Long
Private Declare Function WriteFile Lib “kernel32” (ByVal hFile As Long, lpBuffer As Any, ByVal nNumberOfBytesToWrite As Long, lpNumberOfBytesWritten As Long, ByVal lpOverlapped As Long) As Long
Private Declare Function GetFileSize Lib “kernel32” (ByVal hFile As Long, lpFileSizeHigh As Long) As Long
Private Declare Function SetFilePointer Lib “kernel32” (ByVal hFile As Long, ByVal lDistanceToMove As Long, lpDistanceToMoveHigh As Long, ByVal dwMoveMethod As Long) As Long
Private Const INVALID_HANDLE_VALUE = -1
Private Const GENERIC_READ = &H80000000
Private Const GENERIC_WRITE = &H40000000
Private Const FILE_SHARE_READ = &H1
Private Const FILE_SHARE_WRITE = &H2
Private Const Create_NEW = 1
Private Const Create_ALWAYS = 2
Private Const OPEN_EXISTING = 3
Private Const OPEN_ALWAYS = 4
Private Const TRUNCATE_EXISTING = 5
Private Const FILE_ATTRIBUTE_NORMAL = &H80
Private Const FILE_BEGIN = 0
Private Const FILE_CURRENT = 1
Private Const FILE_END = 2
'== Unicode ================================================
Private Declare Function MultiByteToWideChar Lib “kernel32” (ByVal CodePage As Long, ByVal dwFlags As Long, ByRef lpMultiByteStr As Any, ByVal cchMultiByte As Long, ByRef lpWideCharStr As Any, ByVal cchWideChar As Long) As Long
Private Declare Function WideCharToMultiByte Lib “kernel32” (ByVal CodePage As Long, ByVal dwFlags As Long, ByRef lpWideCharStr As Any, ByVal cchWideChar As Long, ByRef lpMultiByteStr As Any, ByVal cchMultiByte As Long, ByRef lpDefaultChar As Any, ByVal lpUsedDefaultChar As Long) As Long
Private Const CP_UTF8 As Long = 65001
#End If
'###########################################################
'Unicode编码格式
Public Enum UnicodeEncodeFormat
UEF_ANSI = 0 'ANSI+DBCS
UEF_UTF8 'UTF-8
UEF_UTF16LE 'UTF-16LE
UEF_UTF16BE 'UTF-16BE
UEF_UTF32LE 'UTF-32LE
UEF_UTF32BE 'UTF-32BE
UEF_Auto = -1 '自动识别编码
'隐藏项目
[_UEF_Min] = UEF_ANSI
[_UEF_Max] = UEF_UTF32BE
End Enum
'ANSI+DBCS方式的文本所使用的代码页。默认为0,表示使用系统当前代码页。可以利用该参数实现读取其他代码编码的文本,比如想在 简体中文平台下 读取 繁体中文平台生成的txt,就将它设为950
Public UEFCodePage As Long
'判断BOM
'返回值:BOM所占字节
'dwFirst:[in]文件最开始的4个字节
'fmt:[out]返回编码类型
Public Function UEFCheckBOM(ByVal dwFirst As Long, ByRef fmt As UnicodeEncodeFormat) As Long
If dwFirst = &HFEFF& Then
fmt = UEF_UTF32LE
UEFCheckBOM = 4
ElseIf dwFirst = &HFFFE0000 Then
fmt = UEF_UTF32BE
UEFCheckBOM = 4
ElseIf (dwFirst And &HFFFF&) = &HFEFF& Then
fmt = UEF_UTF16LE
UEFCheckBOM = 2
ElseIf (dwFirst And &HFFFF&) = &HFFFE& Then
fmt = UEF_UTF16BE
UEFCheckBOM = 2
ElseIf (dwFirst And &HFFFFFF) = &HBFBBEF Then
fmt = UEF_UTF8
UEFCheckBOM = 3
Else
fmt = UEF_ANSI
UEFCheckBOM = 0
End If
End Function
'生成BOM
'返回值:BOM所占字节
'fmt:[in]编码类型
'dwFirst:[out]文件最开始的4个字节
Public Function UEFMakeBOM(ByVal fmt As UnicodeEncodeFormat, ByRef dwFirst As Long) As Long
Select Case fmt
Case UEF_UTF8
dwFirst = &HBFBBEF
UEFMakeBOM = 3
Case UEF_UTF16LE
dwFirst = &HFEFF&
UEFMakeBOM = 2
Case UEF_UTF16BE
dwFirst = &HFFFE&
UEFMakeBOM = 2
Case UEF_UTF32LE
dwFirst = &HFEFF&
UEFMakeBOM = 4
Case UEF_UTF32BE
dwFirst = &HFFFE0000
UEFMakeBOM = 4
Case Else
dwFirst = 0
UEFMakeBOM = 0
End Select
End Function
'判断文本文件的编码类型
'返回值:编码类型。文件无法打开时,返回UEF_Auto
'FileName:文件名
Public Function UEFCheckTextFileFormat(ByVal FileName As String) As UnicodeEncodeFormat
Dim hFile As Long
Dim dwFirst As Long
Dim nNumRead As Long
'打开文件
hFile = CreateFile(FileName, GENERIC_READ, FILE_SHARE_READ or FILE_SHARE_WRITE, ByVal 0&, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, ByVal 0&)
If INVALID_HANDLE_VALUE = hFile Then '文件无法打开
UEFCheckTextFileFormat = UEF_Auto
Exit Function
End If
'判断BOM
dwFirst = 0
Call ReadFile(hFile, dwFirst, 4, nNumRead, ByVal 0&)
nNumRead = UEFCheckBOM(dwFirst, UEFCheckTextFileFormat)
'Debug.Print nNumRead
'关闭文件
Call CloseHandle(hFile)
End Function
'读取文本文件
'返回值:读取的文本。返回vbNullString表示文件无法打开
'FileName:[in]文件名
'fmt:[in,out]使用何种文本编码格式来读取文本。为UEF_Auto时表示自动判断,且在fmt参数返回文本所用编码格式
Public Function UEFLoadTextFile(ByVal FileName As String, Optional ByRef fmt As UnicodeEncodeFormat = UEF_Auto) As String
Dim hFile As Long
Dim nFileSize As Long
Dim nNumRead As Long
Dim dwFirst As Long
Dim CurFmt As UnicodeEncodeFormat
Dim cbBOM As Long
Dim cbTextData As Long
Dim CurCP As Long
Dim byBuf() As Byte
Dim cchStr As Long
Dim I As Long
Dim byTemp As Byte
'判断fmt范围
If fmt <> UEF_Auto Then
If fmt < [_UEF_Min] or fmt > [_UEF_Max] Then
GoTo FunEnd
End If
End If
'打开文件
hFile = CreateFile(FileName, GENERIC_READ, FILE_SHARE_READ or FILE_SHARE_WRITE, ByVal 0&, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, ByVal 0&)
If INVALID_HANDLE_VALUE = hFile Then '文件无法打开
GoTo FunEnd
End If
'判断文件大小
nFileSize = GetFileSize(hFile, nNumRead)
If nNumRead <> 0 Then '超过4GB
GoTo FreeHandle
End If
If nFileSize < 0 Then &#\n39;超过2GB GoTo FreeHandle End If '判断BOM dwFirst = 0 Call ReadFile(hFile, dwFirst, 4, nNumRead, ByVal 0&) cbBOM = UEFCheckBOM(dwFirst, CurFmt) '恢复文件指针 If fmt = UEF_Auto Then '自动判断 fmt = CurFmt 'cbBOM = cbBOM Else '手动设置编码 If fmt = CurFmt Then '若编码相同,则忽略BOM标记 'cbBOM = cbBOM Else '编码不同,那么都是数据 cbBOM = 0 End If End If Call SetFilePointer(hFile, cbBOM, ByVal 0&, FILE_BEGIN) cbTextData = nFileSize - cbBOM '读取数据 UEFLoadTextFile = "" Select Case fmt Case UEF_ANSI, UEF_UTF8 '判断应使用的CodePage CurCP = IIf(fmt = UEF_UTF8, CP_UTF8, UEFCodePage) '分配缓冲区 On Error GoTo FreeHandle ReDim byBuf(0 To cbTextData - 1) On Error GoTo 0 '读取数据 nNumRead = 0 Call ReadFile(hFile, byBuf(0), cbTextData, nNumRead, ByVal 0&) '取得Unicode文本长度 cchStr = MultiByteToWideChar(CurCP, 0, byBuf(0), nNumRead, ByVal 0&, ByVal 0&) If cchStr > 0 Then
'分配字符串空间
On Error GoTo FreeHandle
UEFLoadTextFile = String$(cchStr, 0)
On Error GoTo 0
'取得文本
cchStr = MultiByteToWideChar(CurCP, 0, byBuf(0), nNumRead, ByVal StrPtr(UEFLoadTextFile), cchStr + 1)
End If
Case UEF_UTF16LE
cchStr = (cbTextData + 1) \\ 2
'分配字符串空间
On Error GoTo FreeHandle
UEFLoadTextFile = String$(cchStr, 0)
On Error GoTo 0
'取得文本
nNumRead = 0
Call ReadFile(hFile, ByVal StrPtr(UEFLoadTextFile), cbTextData, nNumRead, ByVal 0&)
'修正文本长度
cchStr = (nNumRead + 1) \\ 2
If cchStr > 0 Then
If Len(UEFLoadTextFile) > cchStr Then
UEFLoadTextFile = Left$(UEFLoadTextFile, cchStr)
End If
Else
UEFLoadTextFile = “”
End If
Case UEF_UTF16BE
'分配缓冲区
On Error GoTo FreeHandle
ReDim byBuf(0 To cbTextData – 1)
On Error GoTo 0
'读取数据
nNumRead = 0
Call ReadFile(hFile, byBuf(0), cbTextData, nNumRead, ByVal 0&)
If nNumRead > 0 Then
'隔两字节翻转相邻字节
For I = 0 To nNumRead – 1 – 1 Step 2 '再-1是为了避免最后多出的那个字节
byTemp = byBuf(I)
byBuf(I) = byBuf(I + 1)
byBuf(I + 1) = byTemp
Next I
'取得文本
UEFLoadTextFile = byBuf 'VB允许String中的字符串数据与Byte数组直接转换
End If
Case UEF_UTF32LE
UEFLoadTextFile = vbNullString '暂时不支持
Case UEF_UTF32BE
UEFLoadTextFile = vbNullString '暂时不支持
Case Else
Debug.Assert False
End Select
FreeHandle:
'关闭文件
Call CloseHandle(hFile)
FunEnd:
End Function
'保存文本文件
'返回值:是否成功
'FileName:[in]文件名
'sText:[in]欲输出的文本
'IsAppend:[in]是否是添加方式
'fmt:[in,out]使用何种文本编码格式来存储文本。当IsAppend=True时允许UEF_Auto自动判断,且在fmt参数返回文本所用编码格式
'DefFmt:[in]当使用添加模式时,若文件不存在且fmt = UEF_Auto时应使用的编码格式
Public Function UEFSaveTextFile(ByVal FileName As String, _
ByRef sText As String, Optional ByVal IsAppend As Boolean = False, _
Optional ByRef fmt As UnicodeEncodeFormat = UEF_Auto, Optional ByVal DefFmt As UnicodeEncodeFormat = UEF_ANSI) As Boolean
Dim hFile As Long
Dim nFileSize As Long
Dim nNumRead As Long
Dim dwFirst As Long
Dim cbBOM As Long
Dim CurCP As Long
Dim byBuf() As Byte
Dim cbBuf As Long
Dim I As Long
Dim byTemp As Byte
'判断fmt范围
If IsAppend And (fmt = UEF_Auto) Then
Else
If fmt < [_UEF_Min] or fmt > [_UEF_Max] Then
GoTo FunEnd
End If
End If
'打开文件
hFile = CreateFile(FileName, GENERIC_READ or GENERIC_WRITE, FILE_SHARE_READ or FILE_SHARE_WRITE, ByVal 0&, IIf(IsAppend, OPEN_ALWAYS, Create_ALWAYS), FILE_ATTRIBUTE_NORMAL, ByVal 0&)
If INVALID_HANDLE_VALUE = hFile Then '文件无法打开
GoTo FunEnd
End If
'判断文件大小
nFileSize = GetFileSize(hFile, nNumRead)
If nFileSize = 0 And nNumRead = 0 Then '文件大小为0字节
IsAppend = False '此时需要写BOM标志
If fmt = UEF_Auto Then fmt = DefFmt
End If
'判断BOM
If IsAppend And (fmt = UEF_Auto) Then
dwFirst = 0
Call ReadFile(hFile, dwFirst, 4, nNumRead, ByVal 0&)
cbBOM = UEFCheckBOM(dwFirst, fmt)
ElseIf IsAppend = False Then
cbBOM = UEFMakeBOM(fmt, dwFirst)
End If
'文件指针定位
Call SetFilePointer(hFile, 0, ByVal 0&, IIf(IsAppend, FILE_END, FILE_BEGIN))
'写BOM
If IsAppend = False Then
If cbBOM > 0 Then
Call WriteFile(hFile, dwFirst, cbBOM, nNumRead, ByVal 0&)
End If
End If
'写文本数据
If Len(sText) > 0 Then
Select Case fmt
Case UEF_ANSI, UEF_UTF8
'判断应使用的CodePage
CurCP = IIf(fmt = UEF_UTF8, CP_UTF8, UEFCodePage)
'取得缓冲区大小
cbBuf = WideCharToMultiByte(CurCP, 0, ByVal StrPtr(sText), Len(sText), ByVal 0&, 0, ByVal 0&, ByVal 0&)
If cbBuf > 0 Then
'分配缓冲区
On Error GoTo FreeHandle
ReDim byBuf(0 To cbBuf)
On Error GoTo 0
'转换文本
cbBuf = WideCharToMultiByte(CurCP, 0, ByVal StrPtr(sText), Len(sText), byBuf(0), cbBuf + 1, ByVal 0&, ByVal 0&)
'写文件
Call WriteFile(hFile, byBuf(0), cbBuf, nNumRead, ByVal 0&)
UEFSaveTextFile = True
End If
Case UEF_UTF16LE
'写文件
Call WriteFile(hFile, ByVal StrPtr(sText), LenB(sText), nNumRead, ByVal 0&)
UEFSaveTextFile = True
Case UEF_UTF16BE
'将字符串中的数据复制到byBuf
On Error GoTo FreeHandle
byBuf = sText
On Error GoTo 0
cbBuf = UBound(byBuf) – LBound(byBuf) + 1
'隔两字节翻转相邻字节
For I = 0 To cbBuf – 1 – 1 Step 2 '再-1是为了避免最后多出的那个字节
byTemp = byBuf(I)
byBuf(I) = byBuf(I + 1)
byBuf(I + 1) = byTemp
Next I
'写文件
Call WriteFile(hFile, byBuf(0), cbBuf, nNumRead, ByVal 0&)
UEFSaveTextFile = True
Case UEF_UTF32LE
UEFSaveTextFile = False '暂时不支持
Case UEF_UTF32BE
UEFSaveTextFile = False '暂时不支持
Case Else
Debug.Assert False
End Select
Else
UEFSaveTextFile = True
End If
FreeHandle:
'关闭文件
Call CloseHandle(hFile)
FunEnd:
End Function[/code]