vb.net applications to reload the INI file - vb.net

Question

i write this code to change default printer in windows and work fine but in reload the INI file have a error
this is a code :
Private Sub SetDefaultPrinter(ByVal PrinterName As String, ByVal DriverName As String, ByVal PrinterPort As String)
Dim DeviceLine As String
'rebuild a valid device line string
DeviceLine = PrinterName & "," & DriverName & "," & PrinterPort
'Store the new printer information in the
'[WINDOWS] section of the WIN.INI file for
'the DEVICE= item
Call WriteProfileString("windows", "Device", DeviceLine)
'Cause all applications to reload the INI file
Call SendMessage(HWND_BROADCAST, WM_WININICHANGE, 0, "windows")
End Sub
Private Declare Function WriteProfileString Lib "kernel32" Alias "WriteProfileStringA" (ByVal lpszSection As String, ByVal lpszKeyName As String, ByVal lpszString As String) As Long
Private Declare Function SendMessage Lib "user32" Alias "SendMessageA" (ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, ByVal lparam As String) As Long
Private Const HWND_BROADCAST As Long = &HFFFF&
Private Const WM_WININICHANGE As Long = &H1A
and this is a error :
A call to PInvoke function 'Test!Test.Form2::SendMessage' 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.
Does anyone have an idea to solve this problem?
Thankful

Answer 1

Private Declare Function SendMessage Lib "user32" Alias "SendMessageA" ( _
ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, _
ByVal lparam As String) As Long
Your data types are wrong. The hwnd parameter is pointer sized, wMsg is a 32 bit value, and wParam, lParam and the return value are pointer sized. Note that Long is a 64 bit type.
Instead it should be
Private Declare Function SendMessage Lib "user32" Alias "SendMessageA" ( _
ByVal hwnd As IntPtr, ByVal wMsg As Integer, ByVal wParam As IntPtr, _
ByVal lparam As String) As IntPtr
Note that I recommend that, in the modern day, you use pinvoke declarations rather than Declare. This offer much more flexibility.