有关c#程序和用delphi作的dll之间的参数传递问题

Question

library CalcExps;uses
  ShareMem,
  SysUtils,
  Classes,
  ExPars;{$R *.RES}function CalcExpars(pwsExp:pwidechar):pwidechar; stdcall; //
var srel:string;
    ExprParser: TExParser;
    tsExp:tstringlist;
    pya:pbytearray;
    i:integer;
    strExp:string;
begin
  strExp:=WideCharToString(pwsExp);
  if strExp='abc' then
    result:='abc is true'
  else
    result:='abc is false';
end;
exports
  CalcExpars;
begin
end.