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.