WinAPI 字符及字符串函数(11): lstrcpyn - 复制字符串, 同时指定要复制的长度
unit Unit1;

interface

uses
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 TForm1.Button1Click(Sender: TObject);
var
p: PChar;
buf: array[0..255] of Char;
begin
p := 'Delphi';

lstrcpyn(buf, p, 3+1);
ShowMessage(buf); {Del}

lstrcpyn(buf, p, -1);
ShowMessage(buf); {Delphi}
end;

end.