简单创建并调用DLL(DLL)

//通过 DLL Wizard 建立： 

library TestDll;

{ 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
SysUtils,
Classes; 


{$R *.res}
function Sum(x,y:Integer):Integer;stdcall;
begin
Result:=x+y;
end;

exports
Sum;

begin
end.

 

//在其他工程调用，如果不在一个工程组，需要在相同目录下、System32下或指定路径； //声明可以在实现区或接口区，这里的函数名要一致，甚至大小写。 
//调用测试： 

unit Main;

interface

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

type
TForm1 =class(TForm)
btn1: TButton;
procedure btn1Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;

var
Form1: TForm1;
function Sum(x,y:Integer):Integer;stdcall;

implementation
function Sum;external'TestDll.dll';

{$R *.dfm}

procedure TForm1.btn1Click(Sender: TObject);
begin
ShowMessage(IntToStr(Sum(1,8)));
end;

end.