fail while reading string

[jimpie]

Hi,

I'm trying to read a file with my following sub:

Public Declare Function GetPrivateProfileString& Lib "kernel32" Alias "GetPrivateProfileStringA" (ByVal AppName$, ByVal KeyName$, ByVal keydefault$, ByVal ReturnedString$, ByVal RSSize&, ByVal FileName$)

    Function ReadFile(ByVal File As String, Header As String, Var As String) As String
        Dim sSpaces As String   ' Max string length
        Dim szReturn As String  ' Return default value if not found

        szReturn = vbNullString
        sSpaces = Space$(5000)

        Try

            Call GetPrivateProfileString(Header, Var, szReturn, sSpaces, Len(sSpaces), File)

            ReadFile = RTrim$(sSpaces)
            ReadFile = Left$(ReadFile, Len(ReadFile) - 1)

        Catch ex As Exception

            MsgBox(String.Format("Error: [{0}] <Yerbato.Text.Files.ReadFile>", ex.Message))
            ReadFile = ""

        End Try

    End Function

but after calling the sub

            MsgBox(File.ReadFile(Application.StartupPath & "/Data/Accounts/" & Username & ".bin", "ACCOUNT", "Username"))

I'll get this error:

PInvokeStackImbalance was detected
Message: A call to PInvoke function 'Yerbato.Text.Files!Yerbato.Text.Files.clsFiles::GetPrivateProfileString' has unbalanced the stack. This is likely because the managed PInvoke signature does not match the unmanaged target signature. Check that the calling convention and parameters of the PInvoke signature match the target unmanaged signature.

How can I fix this?

[jmcilhinney]

I suggest that you get out of the habit of using those suffixes to specify the type of something. It's a great way to make your code difficult to read. I know that $ makes something a String but I have no recollection what & does because I never use it, never want to use it and never want to see anyone else use it. I'm going to guess that it makes something a Long, because that error message usually results from using a declaration written for VB6 in VB.NET. Most API functions work with 32-bit numbers, which means Long in VB6. A Long in VB.NET is 64-bit though, which is what causes the issue. Any declaration that uses Long in VB6 must use Integer in VB.NET.

[Niya]

The function signature is wrong and I agree with jmc, you should avoid those suffixes like a plague. Use this declaration:-

Public Declare Function GetPrivateProfileString Lib "Kernel32.dll" Alias "GetPrivateProfileStringA" (ByVal lpAppName As String, ByVal lpKeyName As String, ByVal lpDefault As String, ByVal lpReturn As String, ByVal nSize As Integer, ByVal lpFileName As String) As Integer

[jimpie]

I suggest that you get out of the habit of using those suffixes to specify the type of something. It's a great way to make your code difficult to read. I know that $ makes something a String but I have no recollection what & does because I never use it, never want to use it and never want to see anyone else use it. I'm going to guess that it makes something a Long, because that error message usually results from using a declaration written for VB6 in VB.NET. Most API functions work with 32-bit numbers, which means Long in VB6. A Long in VB.NET is 64-bit though, which is what causes the issue. Any declaration that uses Long in VB6 must use Integer in VB.NET.

Hi,

How would I do this in vb.net langlauge then? (instead of vb6)

the code must easy write and read files, like possible with my code above (in vb6)

I need it to save and load accounts from my server.

in vb6 my file looked like this:

[ACCOUNT]
login=test
password=12345
name=herodimus
level=1

it was pretty easy to get the values of username, password, name and the level.

How can I make a code what can easily write and read a specific thing of the file?

[jimpie]

The function signature is wrong and I agree with jmc, you should avoid those suffixes like a plague. Use this declaration:-

Public Declare Function GetPrivateProfileString Lib "Kernel32.dll" Alias "GetPrivateProfileStringA" (ByVal lpAppName As String, ByVal lpKeyName As String, ByVal lpDefault As String, ByVal lpReturn As String, ByVal nSize As Integer, ByVal lpFileName As String) As Integer

Actually it does not fix the error :/

[Niya]

You posted same time as me so you missed my post.....I gave you the proper signature.

EDIT:-
Are you still getting a stack imbalanced error ?

[jimpie]

You posted same time as me so you missed my post.....I gave you the proper signature.

EDIT:-
Are you still getting a stack imbalanced error ?

Yes,

PInvokeStackImbalance was detected
Message: A call to PInvoke function 'Yerbato.Text.Files!Yerbato.Text.Files.clsFiles::GetPrivateProfileString' has unbalanced the stack. This is likely because the managed PInvoke signature does not match the unmanaged target signature. Check that the calling convention and parameters of the PInvoke signature match the target unmanaged signature.

[Niya]

Try this:-

Function ReadFile(ByVal File As String, ByVal Header As String, ByVal Var As String) As String
        Dim BUFFERLEN As Integer = 5000
        Dim szReturn As String = Space(BUFFERLEN)
        Dim i As Integer
 
        Try
 
            i = GetPrivateProfileString(Header, Var, Nothing, szReturn, BUFFERLEN, File)
 
            ReadFile = szReturn.Substring(0, i)
 
 
        Catch ex As Exception
 
            MsgBox(String.Format("Error: [{0}] <Yerbato.Text.Files.ReadFile>", ex.Message))
            ReadFile = ""
 
        End Try
 
    End Function

[Niya]

Actually that Try....Catch block is pointless....

Function ReadFile(ByVal File As String, ByVal Header As String, ByVal Var As String) As String
        Dim BUFFERLEN As Integer = 5000
        Dim szReturn As String = Space(BUFFERLEN)
        Dim i As Integer
 
        i = GetPrivateProfileString(Header, Var, Nothing, szReturn, BUFFERLEN, File)
 
        If i > 0 Then
            Return szReturn.Substring(0, i)
        Else
            Return ""
        End If
    End Function

[jimpie]

Actually that Try....Catch block is pointless....

Function ReadFile(ByVal File As String, ByVal Header As String, ByVal Var As String) As String
        Dim BUFFERLEN As Integer = 5000
        Dim szReturn As String = Space(BUFFERLEN)
        Dim i As Integer
 
        i = GetPrivateProfileString(Header, Var, Nothing, szReturn, BUFFERLEN, File)
 
        If i > 0 Then
            Return szReturn.Substring(0, i)
        Else
            Return ""
        End If
    End Function

thanks, works fine so far =)

[DataMiser]

Just so you guys know the functions with $ on the end are a bit faster than those without.

I have did some testing in VB6 and in every case I have tested There is a very small increase in speed when using functions like CHR$() Mid$() Right$() vs CHR() Mid() Right() as well as others I have tried.

Personally I usually do not use the $ just for readability but there is a small hit to performance for not using it. In VB6 anyway.

[SJWhiteley]

Just so you guys know the functions with $ on the end are a bit faster than those without.

I have did some testing in VB6 and in every case I have tested There is a very small increase in speed when using functions like CHR$() Mid$() Right$() vs CHR() Mid() Right() as well as others I have tried.

Personally I usually do not use the $ just for readability but there is a small hit to performance for not using it. In VB6 anyway.

Since those functions no longer exist, except as perhaps wrappers to .NET functions, it isn't really relevant. We aren't shoeing horses any more

[DataMiser]

True but part of that piece of code looked like it was actually written in VB6

[Niya]

The reason Chr$ would be faster than Chr in VB6 is because Chr operates on Variants so every time you pass a string to Chr it would have to internally convert it into a Variant hence the performance hit. Such things are not a concern in VB.Net though.