delphi XE7 编写DLL与调用

1、DLL部分代码

library HelloDll;

{ Important note about DLL memory management: ShareMem must be the
first unit in your library's USES clause AND your project's (select
Project-View Source) USES clause if your DLL exports any procedures or
functions that pass strings as parameters or function results. This
applies to all strings passed to and from your DLL--even those that
are nested in records and classes. ShareMem is the interface unit to
the BORLNDMM.DLL shared memory manager, which must be deployed along
with your DLL. To avoid using BORLNDMM.DLL, pass string information
using PChar or ShortString parameters. }

uses
System.SysUtils,
System.Classes;

{$R *.res}
function SayHello(sInPar:WideString;var sOutPar :WideString) :Integer; stdcall;
begin
try
Result:=0;
sOutPar:='Hello,'+sInPar;
Result:=1;
except
on e:exception do
begin
sOutPar:='异常:'+e.Message;
end;
end;
end;
exports
SayHello;
begin
end.

2、‘exe 部分代码

unit Unit1;

interface

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls;

type
TForm1 = class(TForm)
Button1: TButton;
procedure Button1Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;

var
Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
type
//TMyfun = function(iJYLX: Integer; pInpar:PChar;pOutPar: PChar): Integer; stdcall;
TMyfun=function(sInPar:WideString;var sOutPar :WideString) :Integer; stdcall;
var
MyHandle: THandle;
Myfunc:TMyfun;
iRet:Integer;
sInPar,sOutPar:WideString;
//pInPar,pOutPar:PChar;
begin
try

sInPar:='bill';
//StrPCopy(pInpar,sInPar);
//MyHandle:=LoadLibRaRy('hy.intf.ybjkfw.dll');

MyHandle:=LoadLibRaRy('HelloDll.dll');
if MyHandle=0 then
begin
ShowMessage('动态连接库加载失败，其原因（错误代码）是：'+IntToStr(GetLastError));
end;
@MyFunc:=GetProcAddress(MyHandle,'SayHello');
if @Myfunc <> nil then
begin
// iRet := Myfunc(2,pInpar,pOutPar);
// sOutPar :=IntToStr(iRet)+'|'+StrPas(pOutPar);
iRet:= Myfunc(sInPar,sOutPar);
ShowMessage(sOutPar);
end;

except
on e:Exception do
begin
ShowMessage('异常:'+e.Message);
end;
end;
end;

end.

3、设置宿主进程与调试