extra spaces in string when returned from a dll

[slaphap]

I have a dll that takes a string and character length. It is supposed to returned the string justified based on the character length (fixed field sizes). However, when the string returns from the dll its length is twice that specified by the character length variable passed to it. If anyone could provide some insight to this phenomenon I would appreciate it.

[Pinky98]

If I had to guess i would say there is some kind of issue between converting this string between ACSII and UNICODE (wide character) formats.

[slaphap]

Thanks Pinky98.

Is there any work around for this tha I can implement?

[rxbagain]

How are you calling the DLL? Is it using the "Private Declare" method. Try to change the parameter type. Instead of using "Byval var As String", make it a "Byref var as Any" and pass a pointer to a byte array to it.

This is the original code (for example)

Private Declare Function GetWindowsDirectoryW Lib "kernel32" ( _
   ByVal lpBuffer As String, ByVal nSize As String) As Long

Private Sub Form_Load()
   Dim strText As String
   strText = Space(255)
   Call GetWindowsDirectoryW(strText, 255)
   MsgBox strText
End Sub

It will give the result same as yours (as I can understand ur problem). Make the changes like this

Private Declare Function GetWindowsDirectoryW Lib "kernel32" ( _
   ByRef lpBuffer As Any, ByVal nSize As String) As Long

Private Sub Form_Load()
   Dim strText As String, bArrStr() As Byte
   bArrStr = Space(255)
   Call GetWindowsDirectoryW(bArrStr(LBound(bArrStr)), 255)
   strText = bArrStr
   MsgBox strText
End Sub

Hope it will help you

[slaphap]

no luck rxbagain

[rxbagain]

How is the function declared and how are you calling it? Can you post your declaration and the code that calls it here?