利用delphi dll wizard进行dll的编写。创建：保存时改dll名称library test2;uses  SysUtils,  Classes,  forms,  dialogs;{$R *.res}function test():string;begin  showmessage('a');end;exports  test;//必须的beginend.调用：在调用单元的implement下面 function test():string;external 'xxxxxxx\test2.dll';button中调用test方法即可。动态调用dll：type  //晚绑定，也就是动态调用外部函数主要用以下三个命令：  //LoadLibrary：获取 DLL  //GetProcAddress：获取函数  //FreeLibrary：释放  //定义一个过程类型，参数要和需要的函数一致  TMB = function(hWnd: HWND; lpText, lpCaption: PChar; uType: UINT): Integer; stdcall;  TForm1 = class(TForm)    Button1: TButton;    procedure Button1Click(Sender: TObject);    procedure FormCreate(Sender: TObject);    procedure FormDestroy(Sender: TObject);  private    MB: TMB;  {声明函数 MB}    inst: LongWord;  {声明一个变量来记录要使用的 DLL 句柄}  public    { Public declarations }  end;procedure TForm1.FormCreate(Sender: TObject);begin  inst := LoadLibrary('user32.dll');  if inst <> 0 then    MB := GetProcAddress(inst, 'MessageBoxW');end;procedure TForm1.FormDestroy(Sender: TObject);begin  FreeLibrary(inst);  {记得释放}end;