isbadwriteptru.pas

DelphiWin32核心API参考光盘内容.是学习书籍中的源码,便于学习.

unit IsBadWritePtru;

interface

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

type
  TForm1 = class(TForm)
    Button1: TButton;
    Button2: TButton;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.DFM}

procedure TForm1.Button1Click(Sender: TObject);
var
  Testptr: pointer;                       // a pointer of unknown access
  AnArray: array[1..100] of integer;      // test data
begin
  {test for valid write access}
  Testptr := @AnArray;
  if IsBadWritePtr(Testptr,SizeOf(AnArray))
    then ShowMessage('no write access')
    else ShowMessage('valid write access');
end;

procedure TForm1.Button2Click(Sender: TObject);
var
  Testptr: Pointer;                       // a pointer of unknown access
begin
  {test for invalid write access}
  Testptr := Pointer($3FFFFFFF);          // points to a random memory address
  if IsBadWritePtr(Testptr, 1000)
    then ShowMessage('no write access')
    else ShowMessage('valid write access');
end;

end.