在线程中如何接收通过PostThreadMessage()发送的消息？ - 程序开发常见问...

在线程中如何接收通过PostThreadMessage()发送的消息？
  
最好有实例！

  
// 用 PeekMessage 接收
// 一个例子
unit main;
interface
uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  StdCtrls,MyThread;
const
      WM_MyMessage=WM_USER 100;
type
  TForm1 = class(TForm)
    BtnQuitThread: TButton;
    ListBox1: TListBox;
    BtnPost: TButton;
    BtnStart: TButton;
    BtnExit: TButton;
    procedure BtnQuitThreadClick(Sender: TObject);
    procedure BtnStartClick(Sender: TObject);
    procedure BtnPostClick(Sender: TObject);
    procedure BtnExitClick(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
      MyThread : MsgThread;
  end;
var
  Form1: TForm1;
implementation
{$R *.DFM}
procedure TForm1.BtnQuitThreadClick(Sender: TObject);
begin
//  MyThread.Terminate;
  if MyThread = nil then exit;
  if PostThreadMessage(MyThread.ThreadID,
      WM_QUIT,0,0) then
      Caption := ‘Post Message Ok!‘
  else
      Caption := ‘Post Message Fail!‘;
end;
procedure TForm1.BtnStartClick(Sender: TObject);
begin
  if (MyThread = nil) then
      MyThread := MsgThread.Create(false);
end;
procedure TForm1.BtnPostClick(Sender: TObject);
begin
  if MyThread = nil then exit;
  if PostThreadMessage(MyThread.ThreadID,
      WM_MyMessage,0,0) then
      Caption := ‘Post Message Ok!‘
  else
      Caption := ‘Post Message Fail!‘;
end;
procedure TForm1.BtnExitClick(Sender: TObject);
begin
  MyThread.Free;
  Close;
end;
end.
///////////// MyThread.pas/////////////////
unit MyThread;
interface
uses
  Classes,windows, Messages;
const
      WM_MyMessage=WM_USER 100;
type
  MsgThread = class(TThread)
  private
    { Private declarations }
    FMyString : string;
  protected
    procedure Execute; override;
    procedure ShowString;
  end;
implementation
{ Important: Methods and properties of objects in VCL can only be used in a
  method called using Synchronize, for example,
      Synchronize(UpdateCaption);
  and UpdateCaption could look like,
    procedure PMessage.UpdateCaption;
    begin
      Form1.Caption := ‘Updated in a thread‘;
    end; }
{ PMessage }
uses Main;
procedure MsgThread.Execute;
var Msg : TMsg;
begin
  { Place thread code here }
  FMyString := ‘Thread Start!‘;
  Synchronize(ShowString);
  while  (not Terminated) do
  begin
      if PeekMessage(Msg,0,0,0,PM_REMOVE) then
        begin
if (Msg.message = WM_QUIT) then
  begin
    FMyString := ‘Thread Quit‘;
    Synchronize(ShowString);
    Terminate;
  end;
if (Msg.message = WM_MyMessage) then
  begin
    FMyString := ‘Thread Get a USER Message!‘;
    Synchronize(ShowString);
  end;
        end;
  end;
end;
procedure MsgThread.ShowString;
begin
   Form1.ListBox1.Items.Add(FMyString);
end;
end.