Hosting CLR in Delphi with/without JCL - example

Question

Can somebody please post here an example how to host CLR in Delphi? I have read similar question here but I cannot use JCL as I want to host it in Delphi 5. Thank you.

Answer 1

Here you go:

program CallDotNetFromDelphiWin32;

{$APPTYPE CONSOLE}

uses
  Variants, JclDotNet, mscorlib_TLB, SysUtils;

var
  Host: TJclClrHost;
  Obj: OleVariant;
begin
  try
    Host := TJclClrHost.Create;
    Host.Start;
    WriteLn('CLRVersion = ' + Host.CorVersion);

    Obj := Host.DefaultAppDomain.CreateInstance('DelphiNET', 'DelphiNET.NETAdder').UnWrap;
    WriteLn('2 + 3 = ' + IntToStr(Obj.Add3(2)));

    Host.Stop;
  except
    on E: Exception do
      Writeln(E.Classname, ': ', E.Message);
  end;
end.

Note: Assumes that the DelphiNET.NETAdder type and the Add3 method in DelphiNet.dll is ComVisible. Thanks to Robert.

Update:

When using reflection you do not need the ComVisible attribute. Next example even works without being ComVisible.

Assm := Host.DefaultAppDomain.Load_2('NetAddr');
T := Assm.GetType_2('DelphiNET.NETAdder');
Obj := T.InvokeMember_3('ctor', BindingFlags_CreateInstance, nil, null, nil);
Params := VarArrayOf([2]);
WriteLn('2 + 3 = ' + IntToStr(T.InvokeMember_3('Add3', BindingFlags_InvokeMethod, nil, Obj, PSafeArray(VarArrayAsPSafeArray(Params)))));