Question

VB时实写入文件

用VB写日志文件，VB默认是在文件关闭的时候才将文件内容写入磁盘，没关闭的时候写入的内容存在缓冲区里面，请写代码可以将写入的内容时实的写入到磁盘上（内容为文本形式），用API也可以。

每写入一行就把文件打开并关闭一次的方法不考虑。

写入动作并不连续，基本上每一个函数里面写入一次，但希望每执行一次写入动作就将内容真正写入到磁盘上

Answer 1

Dim FileNum As Long

Private Sub Command1_Click()
Print #FileNum, "按钮单击事件 " & Now
End Sub

Private Sub Command1_MouseMove(Button As Integer, Shift As Integer, X As Single, Y As Single)
Print #FileNum, "按钮鼠标移动事件 " & Now
End Sub

Private Sub Form_Load()
FileNum = FreeFile
Open App.Path & "\log.txt" For Append As #FileNum
End Sub

Private Sub Form_QueryUnload(Cancel As Integer, UnloadMode As Integer)
Close #FileNum
End Sub

追问

这个程序没退出前，文件里面都是空的，并没有真正写在磁盘上

追答

你好好测试下我的代码在说 OK？

Answer 2

可以考虑用ini文件,这个可以实时写入,而且不用打开关闭文件,代码如下:
'--------cIniFile.cls 代码----------------
'这里定义了一个cIniFile类
Option Explicit

'// Private member that holds a reference to
'// the path of our ini file
Private strInI As String

'// Win API Declares
Private Declare Function WritePrivateProfileString _
Lib "kernel32" Alias "WritePrivateProfileStringA" _
(ByVal lpApplicationName As String, _
ByVal lpKeyName As Any, _
ByVal lpString As Any, _
ByVal lpFileName As String) As Long

Private Declare Function GetPrivateProfileString _
Lib "kernel32" Alias "GetPrivateProfileStringA" _
(ByVal lpApplicationName As String, _
ByVal lpKeyName As Any, _
ByVal lpDefault As String, _
ByVal lpReturnedString As String, _
ByVal nSize As Long, _
ByVal lpFileName As String) As Long

Private Function MakePath(ByVal strDrv As String, _
ByVal strDir As String) As String

'// Makes an INI file: Guarantees a sub dir
Do While Right$(strDrv, 1) = "\"
strDrv = Left$(strDrv, Len(strDrv) - 1)
Loop

Do While Left$(strDir, 1) = "\"
strDir = Mid$(strDir, 2)
Loop

'// Return the path
MakePath = strDrv & "\" & strDir
End Function

Public Sub CreateIni(strDrv As String, strDir As String)

'// Make a new ini file
strInI = MakePath(strDrv, strDir)
End Sub

Public Sub WriteFile(strSection As String, _
strKey As String, _
strValue As String)

'// Write to strINI
WritePrivateProfileString strSection, _
strKey, strValue, strInI
End Sub

Public Function GetFile(strSection As String, _
strKey As String) As String

Dim strTmp As String
Dim lngRet As String

strTmp = String$(100, Chr(32))
lngRet = GetPrivateProfileString(strSection, _
strKey, "", strTmp, _
Len(strTmp), strInI)
'strUser = Trim(myIniFile.GetFile("setting", "username"))
'strUser = Left(strUser, Len(strUser) - 1)
strTmp = Trim(strTmp)
strTmp = Left(strTmp, Len(strTmp) - 1)
GetFile = strTmp

End Function

Public Property Let INIFile(ByVal New_IniPath As String)

'// Sets the new ini path
strInI = New_IniPath

End Property

Public Property Get INIFile() As String

'// Returns the current ini path
INIFile = strInI

End Property

'--------cIniFile.cls 使用举例----------------

' Dim myIniFile As New cIniFile

'---指定访问的ini文件
' If Len(App.Path) > 3 Then
'under disk root dir , eg: "C:\"
' myIniFile.INIFile = App.Path & "\setting.ini"
' Else
' myIniFile.INIFile = App.Path & "setting.ini"
' End If

'---写入ini文件
' myIniFile.WriteFile "setting", "username", strUser

'---读出ini文件的数据
' 注意，如果是字符串，则去掉末尾一个字符
' ----flybird@chinaasp.com
' strUser = Trim(myIniFile.GetFile("setting", "username"))
' strUser = Left(strUser, Len(strUser) - 1)

追问

我的日志文件不想写成 n=xxxxxxxx 这种形式的

Answer 3

这个你的告诉我你是用哪个接口写文件的。
如果是windows api，你可以考虑这个
FlushFileBuffers

追问

我用的是VB的OPEN 打开文件的，不行，FlushFileBuffers 这个API好像能行，但请给出完整的代码

追答

FlushFileBuffers 就一个参数，就是你的文件句柄。
BOOL FlushFileBuffers( HANDLE hFile);
没有flush以前在内存，flush就是把内存的东西放在磁盘上。