PtrToStructure Marshal

[krascso]

Hi everybody.

I have a structure in unmanaged C++:

struct TLogonParams
{
    char name[100];
    char pswd[100];
    char alias[100];
 
    int  loggedon;
    int  DBType;         
    int  super;           
    int  idUser;          
    char UserName[100];  
};
 

and a function:

EXPORT_TYPE TLogonParams* __stdcall GetLogonParams(bool AUseDefault = true);
 
///////////////////////////////////////////////////////////////////////////////////////////////////////////////
 

A would like to call this function from C# and I did this for it:

public class Hdologon3Csharp
{
      public Hdologon3Csharp()
      {
      }
 
[StructLayout(LayoutKind.Explicit)]    
public class LogonParams
{
    [FieldOffset(0)] public char[] name;
    [FieldOffset(100)] public char[] pswd;
    [FieldOffset(200)] public char[] alias;
 
    [FieldOffset(300)] public int  loggedon;
    [FieldOffset(304)] public int  DBType;
    [FieldOffset(308)] public int  super;
    [FieldOffset(312)] public int  idUser;
    [FieldOffset(316)] public char[] UserName; 
}
 
[DllImport("hdologon3.dll", EntryPoint="GetLogonParams", CharSet = CharSet.Ansi, CallingConvention=CallingConvention.StdCall)]        
public static extern IntPtr GetLogonParams( bool AUseDefault );
public unsafe int getLogonParamsCsharp()
{
    try 
    {
        System.IntPtr iptr = Marshal.AllocHGlobal(416);
 
        iptr = GetLogonParams( true );
 
        object o = (LogonParams)Marshal.PtrToStructure ( iptr, typeof  
                                                                          (LogonParams) );
 
        return 0;
    }
    catch ( Exception e)
    {
        string s = e.Message;                
    }
}
 

I get a value 0 for Iptr and so <undefined> for o.

Can anyone help me with this? I'd be very happy. Thanks.