unit Unit1;

interface

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


type
tyw = class
public
TmpIntA: integer;
TmpIntB: integer;
TmpIntC: integer;
end;

pyw = ^tyw;

type
TForm1 = class(TForm)
Button1: TButton;
procedure Button1Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
function ExecThread(tmpA,tmpB:integer):integer;
function GetSumAB(Tmpyw:pyw):integer;
end;

type
TMyThread = class(TThread)
private

protected
procedure Execute;override;
public
ptmpYW :PYW;
constructor Create(Tmpyw:pyw);virtual;

end;

var
Form1: TForm1;

implementation

{$R *.DFM}


function TForm1.ExecThread(tmpA,tmpB:integer):integer;
var
yw : pyw;
fyw: tyw;
begin
fyw := tyw.Create;
yw := @fyw;
fyw.TmpIntA := 1;
fyw.TmpIntB := 2;
if GetSumAB(yw) = 0 then
showmessage(IntToStr(yw.TmpIntC));
end;

function TForm1.GetSumAB(Tmpyw:pyw):integer;
begin
//这里创建一个线程，在线程中执行fyw.TmpIntA和fyw.TmpIntB的和，然后赋给fyw.TmpIntC
result := 1;
try
TMyThread.Create(Tmpyw);
result := 0;
except
result := 1;
end;
end;


constructor TMyThread.Create(Tmpyw:pyw);
begin
inherited Create(True);
FreeOnTerminate := True;
　 Resume;
end;

procedure TMyThread.Execute;
begin
ptmpYW.TmpIntC := ptmpYW.TmpIntB + ptmpYW.TmpIntA;
/////////////////在此处设置断点后，ptmpYW.TmpIntC的值是Inaccessible value//////////////////
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
ExecThread(1,2);
end;

end.