Question

I’m trying to compile This Example for unmanaged export in XE but I getting (PE9) Unknown identifier “UnmanagedExport” error when build.

1. Under Compatibility select “Allow unsafe code”
2. Under Build, find the General Section and change CPU Type to “x86”
3. Right Click on the “ClassLibraryX” tab that was created and select “Save selected Items”

namespace exptest;

interface
    uses
      System.Runtime.InteropServices;

type
  clstest = public static class
  private
  protected
  public

     [UnmanagedExport('xmsg',CallingConvention.StdCall)]
      function xmsg(amsg : String):String;
  end;

implementation

    function clstest.xmsg(amsg: String):String;
    Begin
        Result := amsg + ' mesajı için geri dönüş';
    end;



end.

Error Window

Any idea?

@David:Thanks for answer. I’ve tried your tip

public

     [UnmanagedExport('xmsg',CallingConvention.StdCall)]
      class method xmsg(amsg : String):String;
  end;

implementation

    class method clstest.xmsg(amsg: String):String;
    Begin
        Result := amsg + ' mesajı için geri dönüş';
    end;

but same error is continues.

@David 2 :):

I’ve changed code in this way:

namespace exptest;

interface
    uses
      RemObjects.Oxygene.System;

type
  clstest = public class
  private
  protected
  public

     [UnmanagedExport('xmsg',CallingConvention.StdCall)]
      class method xmsg(amsg : String):String;
  end;

implementation

    class method clstest.xmsg(amsg: String):String;
    Begin
        Result := amsg + ' mesajı için geri dönüş';
    end;



end.

Same error 🙂

@david 3

namespace exptest;

interface
    uses
      RemObjects.Oxygene.System,System.Runtime.InteropServices;


type
  clstest = public class
  private
  protected
  public

     [UnmanagedExport('xmsg',CallingConvention.StdCall)]
      class method xmsg(amsg : String):String;
  end;

implementation

    class method clstest.xmsg(amsg: String):String;
    Begin
        Result := 'a return value for '+amsg ;
    end;



end.

still same error. :,(
Can you try on your prism ide my sample project for me please? Thanks for answers.

    C:\Program Files\Embarcadero\Delphi Prism\bin>oxygene -version
RemObjects Oxygene for .NET - Version 4.0.25.791
Copyright RemObjects Software 2003-2009. All rights reserved.
Exclusively licensed for Delphi Prism.

  Configuration Release not found

my oxygene version 4.0.25.791 I suppose.

…………………………

@David: I tried compile on command line too. here is results

C:\Documents and Settings\XPMUser\Desktop\exptest\exptest>oxygene /allowunsafe:y
es /type:library /cputype:x86 clstest.pas
RemObjects Oxygene for .NET - Version 4.0.25.791
Copyright RemObjects Software 2003-2009. All rights reserved.
Exclusively licensed for Delphi Prism.

  Preparing resources...
  Compiling...
  C:\Documents and Settings\XPMUser\Desktop\exptest\exptest\clstest.pas(14,22) :
 Error : (PE9) Unknown identifier "UnmanagedExport"

  Exiting with 1.

C:\Documents and Settings\XPMUser\Desktop\exptest\exptest>

probably your right. maybe something wrong with my compiler. But i didnt see any error during install Delphi prism.

@Rudy: I was tried VS2010 ide before this. As I Said. Maybe i reinstall delphi prism or try different machine. I’ll write results if solve.

Answer 1

I Solved problem this way.
RGiesecke.DllExport

using System;
using System.Collections.Generic;
using System.Text;
using RGiesecke.DllExport;
using System.Runtime.InteropServices;
using System.IO;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Windows.Forms;
using System.Configuration;


namespace thenamespace
{

   {

      private static some_members
      ...
      ...
      ...

      [DllExport(CallingConvention = System.Runtime.InteropServices.CallingConvention.StdCall)]
      [return: MarshalAs(UnmanagedType.LPStr)]
      static String GetValue(
          [MarshalAs(UnmanagedType.LPStr)] String _url,
          [MarshalAs(UnmanagedType.LPStr)] String _username,
          [MarshalAs(UnmanagedType.LPStr)] String _password, 
          int _method,
          [MarshalAs(UnmanagedType.LPStr)] String _identid,
          int _isTestMode,
          int _TimeOutAsSecond,
          [MarshalAs(UnmanagedType.LPStr)] String _ProxyAddr,
          [MarshalAs(UnmanagedType.LPStr)] String _ProxyUsername,
          [MarshalAs(UnmanagedType.LPStr)] String _ProxyPassword)
      {
        ...
         return result;
      }



   }
}

And pascal side

_fGetValue = function(_url, _username, _password: pAnsiChar; _method: Integer;
    _identid: pAnsiChar; _isTestMode : Integer; _TimeOutAsSecond:Integer;
    _ProxyAddr:PAnsiChar;_ProxyUsername:PAnsiChar;_ProxyPassword:PAnsiChar): pAnsiChar; stdcall;


...
...
...

var
  dllHandle: cardinal;
  dllFunc: _fGetValue;

  __url, __username, __password, __tckimlik, __result: pAnsiChar;
  __metod: Integer;__ProxyAddr:PAnsiChar;
  __ProxyUsername:PAnsiChar;__ProxyPassword:PAnsiChar;
begin
  Result := '';
  __result := '';

  dllHandle := LoadLibrary('thelib.dll');
  If dllHandle <> 0 then
  begin
    dllFunc := nil;
    @dllFunc := GetProcAddress(dllHandle, 'GetValue');

    if Assigned(dllFunc) then
      __result := dllFunc(__url, __username, __password, __metod, __identid,
      _isTestMode,_TimeOutAsSecond,__ProxyAddr,__ProxyUsername,__ProxyPassword)
    else
    Begin
      raise Exception.Create('Method is not found');
    End;
    Result := __result;
    FreeLibrary(dllHandle);
  end
else
begin
  raise Exception.Create('Library not found thelib.dll');
end;
end;