求助：vb2008 用GetPrivateProfileString读取ini文件无法正确读取

[zjcy2007]

程序清单如下：
==========================================================================================================
Option Explicit On
Public Class Form1
Private Declare Function GetPrivateProfileInt Lib "kernel32" Alias "GetPrivateProfileIntA" (ByVal lpApplicationName As String, ByVal lpKeyName As String, ByVal nDefault As Long, ByVal lpFileName As String) As Int16
Private Declare Function GetPrivateProfileString Lib "kernel32" Alias "GetPrivateProfileStringA" (ByVal lpApplicationName As String, ByVal lpKeyName As String, ByVal lpDefault As String, ByVal lpReturnedString As String, ByVal nSize As Long, ByVal lpFileName As String) As Int16
Private Declare Function WritePrivateProfileString Lib "kernel32 " Alias "WritePrivateProfileStringA " (ByVal lpApplicationName As String, ByVal lpKeyName As String, ByVal lpString As String, ByVal lpFileName As String) As Long
Public ErrorMsg As String
Private Sub new_Initialize()
ErrorMsg = vbNullString
End Sub
'写入----------------------------------
Public Function WriteString(ByVal iniFileName As String, ByVal Section As String, ByVal key As String, ByVal Value As String) As Boolean
WriteString = False
ErrorMsg = vbNullString
If iniFileName = " " Then
ErrorMsg = "INI file has not been specifyed! "
Exit Function
End If
If WritePrivateProfileString(Section, key, Value, iniFileName) = 0 Then
ErrorMsg = "Failed to write to the ini file! "
Exit Function
End If
WriteString = True
End Function
'读出字符串----------------------------
Public Function ReadString(ByVal iniFileName As String, ByVal Section As String, ByVal key As String, ByVal Size As Long) As String
Dim ReturnStr As String
Dim ReturnLng As Long
ErrorMsg = vbNullString
ReadString = vbNullString
If iniFileName = " " Then
ErrorMsg = "INI file has not been specifyed! "
Exit Function
End If
ReturnStr = Space(Size)
ReturnLng = GetPrivateProfileString(Section, key, vbNullString, ReturnStr, Size, iniFileName)
If ReturnLng = 0 Then
ReturnLng = GetPrivateProfileInt(Section, key, 1, iniFileName)
If ReturnLng = 1 Then
ErrorMsg = "Can not read the ini file! "
MsgBox(ErrorMsg, MsgBoxStyle.Critical)
Exit Function
End If
End If
ReadString = Microsoft.VisualBasic.Left(ReturnStr, ReturnLng).Trim
End Function
'读出数值-----------------------------
Public Function ReadInt(ByVal iniFileName As String, ByVal Section As String, ByVal key As String) As Long
Dim ReturnLng As Long
ReadInt = 0
ErrorMsg = vbNullString
If iniFileName = " " Then
ErrorMsg = "INI file has not been specifyed! "
Exit Function
End If
ReturnLng = GetPrivateProfileInt(Section, key, 0, iniFileName)
If ReturnLng = 0 Then
ReturnLng = GetPrivateProfileInt(Section, key, 1, iniFileName)
If ReturnLng = 1 Then
ErrorMsg = "Can not read the ini file! "
MsgBox(ErrorMsg, MsgBoxStyle.Critical)
Exit Function
End If
End If
ReadInt = ReturnLng
End Function
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
MsgBox(ReadString("E:\3GPConverter_3.1\BRVideoConverter.ini", "System Settings", "CVMode", 133), MsgBoxStyle.OkOnly, "sys")
End Sub
==========================================================================================================
ini文件可以任意选取。
程序运行后，总是提示无法读取INI文件，分析后，发现GETPRIVATEPROFILESTING返回的总是0，无论键值是否存在，余百思不得其解，请教大家，问题何在？谢谢

[pjagz]

Public Declare Function GetPrivateProfileString Lib "kernel32" Alias "GetPrivateProfileStringA" (ByVal lpApplicationName As String, ByVal lpKeyName As String, ByVal lpDefault As String, ByVal lpReturnedString As String, ByVal nSize As Int32, ByVal lpFileName As String) As Int32

Dim strIni As New String(" ", 256)
GetPrivateProfileString("Section", "key", "", strIni, 256, iniFileName)
Debug.WriteLine(strIni)

[wuyq11]

Public Class INIClass
Public inipath As String
<DllImport("kernel32")> _
Private Shared Function WritePrivateProfileString(ByVal section As String, ByVal key As String, ByVal val As String, ByVal filePath As String) As Long
End Function
<DllImport("kernel32")> _
Private Shared Function GetPrivateProfileString(ByVal section As String, ByVal key As String, ByVal def As String, ByVal retVal As StringBuilder, ByVal size As Integer, ByVal filePath As String) As Integer
End Function
Public Sub New(ByVal INIPath__1 As String)
inipath = INIPath__1
End Sub
Public Sub IniWriteValue(ByVal Section As String, ByVal Key As String, ByVal Value As String)
WritePrivateProfileString(Section, Key, Value, Me.inipath)
End Sub
Public Function IniReadValue(ByVal Section As String, ByVal Key As String) As String
Dim temp As New StringBuilder(500)
Dim i As Integer = GetPrivateProfileString(Section, Key, "", temp, 500, Me.inipath)
Return temp.ToString()
End Function
Public Function ExistINIFile() As Boolean
Return File.Exists(inipath)
End Function
End Class

[wjq]

lpReturnedString参数声明为StringBuilder

[zjcy2007]

2楼的通过建立一个类也能解决这个问题，但我想知道具体的我这程序那里错了，谢谢

[zjcy2007]

1楼的代码，我试过了，还是不行，问题没解决

[zjcy2007]

3楼给的stringbuild,好像没这个类型吧，在vb2008里

[wjq]

[Quote=引用 6 楼 zjcy2007 的回复:]
3楼给的stringbuild,好像没这个类型吧，在vb2008里
[/Quote]StringBuilder是.NET Framework 1.0开始就有的类…….NET Framework3.5怎么可能没有……

[wangismybliss]

2楼的那个好像也不好用啊，我试过了，得到的值是空

[yanlongwuhui]

API函数声明有误，改成如下试试：
Private Declare Function GetPrivateProfileString Lib "kernel32" Alias "GetPrivateProfileStringA" (ByVal lpApplicationName As String, ByVal lpKeyName As String, ByVal lpDefault As String, ByVal lpReturnedString As String, ByVal nSize As integer, ByVal lpFileName As String) As integer
Private Declare Function WritePrivateProfileString Lib "kernel32" Alias "WritePrivateProfileStringA" (ByVal lpApplicationName As String, ByVal lpKeyName As String, ByVal lpString As String, ByVal lpFileName As String) As integer

[ckp00001]

'将lpReturnedString设成StringBuilder类,代码如下:
Imports system.Text
.........
Private Declare Function GetPrivateProfileString Lib "kernel32" Alias "GetPrivateProfileStringA" (ByVal lpMainKey As String, ByVal lpKey As String, ByVal lpDefault As String, ByVal lpReturnedString As StringBuilder, ByVal nSize As Integer, ByVal lpFileName As String) As Integer
'=================================================================================
Dim ReturnSTR As New StringBuilder()
dim Rt as integer = GetPrivateProfileString("RFID01", "RFID01_Write_1", String.Empty, ReturnSTR, 512, "..\..\cfg.ini")
Console.WriteLine(ReturnSTR.ToString)