关于多线程同步，搞来搞去总搞不好，不知道是什么原因！请高手帮帮忙

Question

在窗体上放一个button和两个label，我想让两个label的caption通过两个线程来赋值，但是总得执行完第一个线程后再执行第二个，这还叫多线程么？郁闷！！代码如下，请高手指点。unit Unit1;interfaceuses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;type
  TForm1 = class(TForm)
    Label1: TLabel;
    Label2: TLabel;
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure FormDestroy(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;  TmyThread=Class(TThread)
  public
    Lb:Tlabel;
    constructor Create(Lab:TLabel);
    procedure Execute;
    procedure myVoid;
  end;
  TmyThread2=Class(TThread)
  public
    Lb:Tlabel;
    constructor Create(Lab:TLabel);
    procedure Execute;
    procedure myVoid;
  end;var
  Form1: TForm1;
  T1:TmyThread;
  T2:TmyThread2;
implementation{$R *.dfm}constructor TmyThread.Create(Lab:Tlabel);
begin
  Lb := Lab;
  inherited Create(true);
  FreeOnTerminate := true;
end;procedure TmyThread.Execute;
begin
  Synchronize(myVoid);
end;procedure TmyThread.myVoid;
  var
    i:integer;
begin
  for i:=0 to 10000 do
  begin
    Application.ProcessMessages;
    Lb.Caption := InttoStr(i);
  end;
end;constructor TmyThread2.Create(Lab:Tlabel);
begin
  Lb := Lab;
  inherited Create(true);
  FreeOnTerminate := true;
end;procedure TmyThread2.Execute;
begin
  Synchronize(myVoid);
end;procedure TmyThread2.myVoid;
  var
    i:integer;
begin
  for i:=0 to 10000 do
  begin
    Application.ProcessMessages;
    Lb.Caption := InttoStr(i);
  end;
end;procedure TForm1.Button1Click(Sender: TObject);
begin
  T1.execute;
  T2.Execute;
end;procedure TForm1.FormCreate(Sender: TObject);
begin
  T1 := TmyThread.Create(Label1);
  T2 := TmyThread2.Create(Label2);
end;procedure TForm1.FormDestroy(Sender: TObject);
begin
  T1.Terminate;
  T2.Terminate;
end;end.

Answer 1

不会编译错误吧？记得button1,lable1,label2添加这三个控件

Answer 2

unit Unit1;interfaceuses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;type
  TForm1 = class(TForm)
    Label1: TLabel;
    Label2: TLabel;
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;  TmyThread=Class(TThread)
  private
    Lb:Tlabel;
  public
    procedure Execute;override;
    procedure myVoid;
  end;
var
  Form1: TForm1;
  T1,T2:TmyThread;
implementation{$R *.dfm}procedure TmyThread.Execute;
begin
  Synchronize(myVoid);
end;procedure TmyThread.myVoid;
  var
    i:integer;
begin
  for i:=0 to 10000 do
  begin
    Application.ProcessMessages;
    Lb.Caption := InttoStr(i);
  end;
end;procedure TForm1.Button1Click(Sender: TObject);
begin
  T1 := TmyThread.Create(false);
  T2 := TmyThread.Create(false);
  T1.Lb:=label1;T2.Lb:=label2;
  T1.FreeOnTerminate:=true;T2.FreeOnTerminate:=true;
  T1.Resume;T2.Resume;
end;end.

Answer 3

改一下
procedure TForm1.Button1Click(Sender: TObject);
begin
  T1 := TmyThread.Create(false);
  T2 := TmyThread.Create(false);
  T1.Lb:=label1;T2.Lb:=label2;
  T1.FreeOnTerminate:=true;T2.FreeOnTerminate:=true;
  T1.Resume;T2.Resume;
end;

Answer 4

晕，什么也没改，对不起，应该是
TmyThread.Create(true);

Answer 5

改为true一样，第一个跑了点，然后就停了，接着第二个跑到完，然后第一个再接着跑

Answer 6

就是了，两个中一个只跑了一半，我认为是application.ProcessMessages;的原因

Answer 7

如果没有这个我就看不到label在变化了啊

Answer 8

解决了：
用Synchronize同步访问VCL不可能完全有你的效果
如果你这样就解决了，只不过效果要差些：
procedure TmyThread.Execute;
begin
  Synchronize(myVoid);
end;
改为
procedure TmyThread.Execute;
begin
  myVoid;
end;

Answer 9

当然还是要application.ProcessMessages

Answer 10

好了，完整的代码：
unit Unit1;interfaceuses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;type
  TForm1 = class(TForm)
    Label1: TLabel;
    Label2: TLabel;
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;  TmyThread=Class(TThread)
  private
    Lb:Tlabel;
  public
    procedure Execute;override;
    procedure myVoid;
  end;
var
  Form1: TForm1;
  T1,T2:TmyThread;
implementation{$R *.dfm}procedure TmyThread.Execute;
begin
  myVoid;
end;procedure TmyThread.myVoid;
  var
    i:integer;
begin
  for i:=0 to 10000 do
  begin
    Lb.Caption := InttoStr(i);
    application.ProcessMessages;
  end;
end;procedure TForm1.Button1Click(Sender: TObject);
begin
  T1 := TmyThread.Create(true);
  T2 := TmyThread.Create(true);
  T1.Lb:=label1;T2.Lb:=label2;
  T1.FreeOnTerminate:=true;
  T2.FreeOnTerminate:=true;
  T1.Resume;T2.Resume;
end;end.