Delphi线程类(二)

{*******************************************************}
{                                                       }
{       Delphi Thread Sample 2                          }                            
{       Creation Date 2011.06.30                        }
{       Created By: ming                                }
{                                                       }
{*******************************************************}
unit unitWorkThread;

interface

uses
  Classes,Windows, Messages, SysUtils, Graphics, StdCtrls;

type
  TWorkThread = class(TThread)
  private
    { Private declarations }
    FEvent: HWND;
    FMsg: string;
    FMemo:  TMemo;
    FInterval: Cardinal;
    procedure doSyncProc1;
    procedure doSomething;
    procedure syncOutputMsg;
    procedure doOutputMsg(const msg: string);
    procedure _sleep(millisecond:Cardinal);
  protected
    procedure Execute; override;
  public
    constructor Create(Suspend: boolean); overload;
    constructor Create(Suspend: boolean; mmoOutput: TMemo); overload;
    destructor Destroy; override;
  public
    procedure exitThread;
  public
    property Interval:Cardinal read FInterval write FInterval;
  end;

var
  WorkThread: TWorkThread;
const
  WM_TEST1 = WM_USER + 1000;  //range (WM_USER - $7FFF)
  WM_TEST2 = WM_APP  + 100;   //range (WM_APP  - $BFFF)

implementation

{ TWorkThread }

constructor TWorkThread.Create(Suspend: boolean);
begin
  inherited Create(Suspend);
  FEvent := CreateEvent(nil,False,False,nil);
  FreeOnTerminate := True;
  FInterval := 100;
end;

constructor TWorkThread.Create(Suspend: boolean; mmoOutput: TMemo);
begin
  inherited Create(Suspend);
  FEvent := CreateEvent(nil,False,False,nil);
  FreeOnTerminate := True;
  FInterval := 100;  
  FMemo := mmoOutput;
  doOutputMsg('Thread Create');
end;

destructor TWorkThread.Destroy;
begin
  CloseHandle(FEvent);
  doOutputMsg('Thread Destroy');
  inherited;
end;

procedure TWorkThread.doSyncProc1;
begin

end;

procedure TWorkThread.doOutputMsg(const msg: string);
begin
  FMsg := msg;
  Synchronize(syncOutputMsg);
end;

procedure TWorkThread.syncOutputMsg;
begin
  if Assigned(FMemo) then
    FMemo.Lines.Add(FMsg);
end;

procedure TWorkThread.doSomething;
begin
  //Synchronize(doSyncProc1);
  doOutputMsg(FormatDateTime('HH:NN:SS',now));
end;

{
GetMessage   阻塞模式类似于SendMessage
PeekMessage  非阻塞模式类似于PostMessage
}
{.$DEFINE _BLOCKMSG}
procedure TWorkThread.Execute;
var
  aMsg: TMsg;
begin
  inherited;
  {$IFDEF _BLOCKMSG}
  while GetMessage(aMsg,0,0,0) do
  begin
    case aMsg.message of
      WM_QUIT:
            begin
              Break;
            end;
      WM_TEST1:
            begin
              doOutputMsg('Received Msg1');
              doSomething;
            end;
      WM_TEST2:
            begin
              doOutputMsg('Received Msg2');
              doSomething;
            end;
    end;
  end;
  {$ELSE}
  while not Terminated do
  begin
    if PeekMessage(aMsg,0,0,0,PM_REMOVE) then
    begin
      case aMsg.message of
        WM_QUIT:
              begin
                Break;
              end;
        WM_TEST1:
              begin
                doOutputMsg('Received Msg1');
              end;
        WM_TEST2:
              begin
                doOutputMsg('Received Msg2');
              end;
      end;
    end;
    doSomething;
    _sleep(FInterval);
  end;
  {$ENDIF}
end;

procedure TWorkThread.exitThread;
begin
  PostThreadMessage(Self.ThreadID,WM_QUIT,0,0);
  if Suspended then Resume;
end;

procedure TWorkThread._sleep(millisecond: Cardinal);
begin
  WaitForSingleObject(Self.Handle,millisecond);
end;

{=============================================================}
{uses unitWorkThread;

procedure TForm1.btnCreateThreadClick(Sender: TObject);
begin
  if Assigned(WorkThread) then exit;
  WorkThread := TWorkThread.Create(False,mmoOutput);
  WorkThread.Interval := 1000;
  if WorkThread.Suspended then
    WorkThread.Resume;
end;

procedure TForm1.btnDestroyThreadClick(Sender: TObject);
begin
  if Assigned(WorkThread) then
  begin
    WorkThread.exitThread;
    WorkThread := nil;
  end;
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
  if Assigned(WorkThread) then
    PostThreadMessage(WorkThread.ThreadID,WM_TEST1,0,0);
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
  if Assigned(WorkThread) then
    PostThreadMessage(WorkThread.ThreadID,WM_TEST2,0,0);
end;
}

end.