isbadreadptru.pas

来自「DelphiWin32核心API参考光盘内容.是学习书籍中的源码,便于学习.」· PAS 代码 · 共 52 行

unit IsBadReadPtru;

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;   // pointer to memory block of unknown access
  TestArray: array[1..64] of Integer;
begin
  {try for valid read access}
  Testptr := @TestArray;
  if IsBadReadPtr(Testptr, SizeOf(TestArray))
    then ShowMessage('no read access')
    else ShowMessage('valid read access');
end;

procedure TForm1.Button2Click(Sender: TObject);
var
  Testptr: Pointer;   // pointer to memory block of unknown access
begin
  {try for invalid read access}
  Testptr := nil;
  if IsBadReadPtr(Testptr, 9)
    then ShowMessage('no read access')
    else ShowMessage('valid read access');
end;

end.