本例效果图:
Dll 文件:
library Lib;uses SysUtils, Classes;{$R *.res}procedure Test(p: PChar);const Title = 'Title ';var str: string;begin str := p; StrCopy(p, Title); StrCat(p, PChar(str));end;exports Test;beginend. 调用的代码文件: unit Unit1;interfaceuses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls;type TForm1 = class(TForm) Button1: TButton; procedure Button1Click(Sender: TObject); end;var Form1: TForm1;implementation{$R *.dfm}procedure Test(p: PChar); external 'Lib.dll';var num: Integer;procedure TForm1.Button1Click(Sender: TObject);var p: PChar;begin Inc(num); p := StrAlloc(255); StrCopy(p, PChar(IntToStr(num))); Test(p); Text := p; StrDispose(p);end;end. 调用的窗体文件: object Form1: TForm1 Left = 0 Top = 0 Caption = 'Form1' ClientHeight = 103 ClientWidth = 173 Color = clBtnFace Font.Charset = DEFAULT_CHARSET Font.Color = clWindowText Font.Height = -11 Font.Name = 'Tahoma' Font.Style = [] OldCreateOrder = False PixelsPerInch = 96 TextHeight = 13 object Button1: TButton Left = 48 Top = 40 Width = 75 Height = 25 Caption = 'Button1' TabOrder = 0 OnClick = Button1Click endend