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在delphi线程中实现消息循环

2007-04-27 09:45 281 查看
在delphi线程中实现消息循环

Delphi的TThread类使用很方便,但是有时候我们需要在线程类中使用消息循环,delphi没有提供.花了两天的事件研究了一下win32的消息系统,写了一个线程内消息循环的测试.但是没有具体应用过,贴出来给有这方面需求的DFW参考一下.
希望大家和我讨论.

{-----------------------------------------------------------------------------
 Unit Name: uMsgThread
 Author:    xwing
 eMail :    xwing@263.net ; MSN : xwing1979@hotmail.com
 Purpose:   Thread with message Loop
 History:

 2003-6-19, add function to Send Thread Message.            ver 1.0
            use Event List and waitforsingleObject
            your can use WindowMessage or ThreadMessage
 2003-6-18, Change to create a window to Recving message
 2003-6-17, Begin.
-----------------------------------------------------------------------------}
unit uMsgThread;

interface
{$WARN SYMBOL_DEPRECATED OFF}
{$DEFINE USE_WINDOW_MESSAGE}
uses
    Classes, windows, messages, forms, sysutils;

type
    TMsgThread = class(TThread)
    private
        {$IFDEF USE_WINDOW_MESSAGE}
        FWinName    : string;
        FMSGWin     : HWND;
        {$ELSE}
        FEventList  : TList;
        FCtlSect    : TRTLCriticalSection;
        {$ENDIF}
        FException  : Exception;
        fDoLoop     : Boolean;
        FWaitHandle : THandle;
        {$IFDEF USE_WINDOW_MESSAGE}
        procedure MSGWinProc(var Message: TMessage);
        {$ELSE}
        procedure ClearSendMsgEvent;
        {$ENDIF}
        procedure SetDoLoop(const Value: Boolean);
        procedure WaitTerminate;

    protected
        Msg         :tagMSG;
       
        procedure Execute; override;
        procedure HandleException;
        procedure DoHandleException;virtual;
        //Inherited the Method to process your own Message
        procedure DoProcessMsg(var Msg:TMessage);virtual;
        //if DoLoop = true then loop this procedure
        //Your can use the method to do some work needed loop.        
        procedure DoMsgLoop;virtual;
        //Initialize Thread before begin message loop        
        procedure DoInit;virtual;
        procedure DoUnInit;virtual;

        procedure PostMsg(Msg:Cardinal;wParam:Integer;lParam:Integer);
        //When Use SendMsg method Must not use Synchronize Method in ThreadLoop !!!
        //otherwise will caurse DeadLock
        procedure SendMsg(Msg:Cardinal;wParam:Integer;lParam:Integer);
       
    public
        constructor Create(Loop:Boolean=False;ThreadName: string='');
        destructor destroy;override;
        procedure AfterConstruction;override;

        //postMessage to Quit,and Free(if FreeOnTerminater = true)
        //can call this in thread loop, don't use terminate property.
        procedure QuitThread;
        //PostMessage to Quit and Wait, only call in MAIN THREAD
        procedure QuitThreadWait;
        //just like Application.processmessage.
        procedure ProcessMessage;
        //enable thread loop, no waitfor message
        property DoLoop: Boolean read fDoLoop Write SetDoLoop;

    end;

implementation

{ TMsgThread }
{//////////////////////////////////////////////////////////////////////////////}
constructor TMsgThread.Create(Loop:Boolean;ThreadName:string);
begin
    {$IFDEF USE_WINDOW_MESSAGE}
    if ThreadName <> '' then
        FWinName := ThreadName
    else
        FWinName := 'Thread Window';
    {$ELSE}
    FEventList := TList.Create;
    InitializeCriticalSection(fCtlSect);
    {$ENDIF}

    FWaitHandle := CreateEvent(nil, True, False, nil);

    FDoLoop := Loop;            //default disable thread loop
    inherited Create(False);    //Create thread
    FreeOnTerminate := True;    //Thread quit and free object

    //Call resume Method in Constructor Method
    Resume;
    //Wait until thread Message Loop started    
    WaitForSingleObject(FWaitHandle,INFINITE);
end;

{------------------------------------------------------------------------------}
procedure TMsgThread.AfterConstruction;
begin
end;

{------------------------------------------------------------------------------}
destructor TMsgThread.destroy;
begin
    {$IFDEF USE_WINDOW_MESSAGE}
    {$ELSE}
    FEventList.Free;
    DeleteCriticalSection(FCtlSect);
    {$ENDIF}
   
    inherited;
end;

{//////////////////////////////////////////////////////////////////////////////}
procedure TMsgThread.Execute;
var
    mRet:Boolean;
    aRet:Boolean;
    {$IFNDEF USE_WINDOW_MESSAGE}
    uMsg:TMessage;
    {$ENDIF}
begin
{$IFDEF USE_WINDOW_MESSAGE}
    FMSGWin := CreateWindow('STATIC',PChar(FWinName),WS_POPUP,0,0,0,0,0,0,hInstance,nil);
    SetWindowLong(FMSGWin, GWL_WNDPROC, Longint(MakeObjectInstance(MSGWinProc)));
{$ELSE}
    PeekMessage(Msg,0,WM_USER,WM_USER,PM_NOREMOVE); //Force system alloc a msgQueue
{$ENDIF}

    //notify Conctructor can returen.
    SetEvent(FWaitHandle);
    CloseHandle(FWaitHandle);

    mRet := True;
    try
        DoInit;
        while mRet do   //Message Loop
        begin
            if fDoLoop then
            begin
                aRet := PeekMessage(Msg,0,0,0,PM_REMOVE);
                if aRet and (Msg.message <> WM_QUIT) then
                begin
                    {$IFDEF USE_WINDOW_MESSAGE}
                    TranslateMessage(Msg);
                    DispatchMessage(Msg);
                    {$ELSE}
                    uMsg.Msg := Msg.message;
                    uMsg.wParam := Msg.wParam;
                    uMsg.lParam := Msg.lParam;
                    DoProcessMsg(uMsg);
                    {$ENDIF}

                    if Msg.message = WM_QUIT then
                        mRet := False;
                end;
                {$IFNDEF USE_WINDOW_MESSAGE}
                ClearSendMsgEvent;      //Clear SendMessage Event                
                {$ENDIF}
                DoMsgLoop;
            end
            else begin
                mRet := GetMessage(Msg,0,0,0);
                if mRet then
                begin
                    {$IFDEF USE_WINDOW_MESSAGE}
                    TranslateMessage(Msg);
                    DispatchMessage(Msg);
                    {$ELSE}
                    uMsg.Msg := Msg.message;
                    uMsg.wParam := Msg.wParam;
                    uMsg.lParam := Msg.lParam;
                    DoProcessMsg(uMsg);
                    ClearSendMsgEvent;      //Clear SendMessage Event
                    {$ENDIF}
                end;
            end;
        end;
        DoUnInit;
        {$IFDEF USE_WINDOW_MESSAGE}
        DestroyWindow(FMSGWin);
        FreeObjectInstance(Pointer(GetWindowLong(FMSGWin, GWL_WNDPROC)));
        {$ENDIF}
    except
        HandleException;
    end;
end;

{------------------------------------------------------------------------------}
{$IFNDEF USE_WINDOW_MESSAGE}
procedure TMsgThread.ClearSendMsgEvent;
var
    aEvent:PHandle;
begin
    EnterCriticalSection(FCtlSect);
    try
        if FEventList.Count <> 0 then
        begin
            aEvent := FEventList.Items[0];
            if aEvent <> nil then
            begin
                SetEvent(aEvent^);
                CloseHandle(aEvent^);
                Dispose(aEvent);
            end;
            FEventList.Delete(0);
        end;
    finally
        LeaveCriticalSection(FCtlSect);
    end;
e
fa87
nd;
{$ENDIF}

{------------------------------------------------------------------------------}
procedure TMsgThread.HandleException;
begin
    FException := Exception(ExceptObject);  //Get Current Exception object
    try
        if not (FException is EAbort) then
            inherited Synchronize(DoHandleException);
    finally
        FException := nil;
    end;
end;

{------------------------------------------------------------------------------}
procedure TMsgThread.DoHandleException;
begin
    if FException is Exception then
        Application.ShowException(FException)
    else
        SysUtils.ShowException(FException, nil);
end;

{//////////////////////////////////////////////////////////////////////////////}
{$IFDEF USE_WINDOW_MESSAGE}
procedure TMsgThread.MSGWinProc(var Message: TMessage);
begin
    DoProcessMsg(Message);
    with Message do
        Result:=DefWindowProc(FMSGWin,Msg,wParam,lParam);
end;
{$ENDIF}

{------------------------------------------------------------------------------}
procedure TMsgThread.DoProcessMsg(var Msg:TMessage);
begin
end;

{------------------------------------------------------------------------------}
procedure TMsgThread.ProcessMessage;
{$IFNDEF USE_WINDOW_MESSAGE}
var
    uMsg:TMessage;
{$ENDIF}
begin
    while PeekMessage(Msg,0,0,0,PM_REMOVE) do
    if Msg.message <> WM_QUIT then
    begin
        {$IFDEF USE_WINDOW_MESSAGE}
        TranslateMessage(Msg);
        DispatchMessage(msg);
        {$ELSE}
        uMsg.Msg := Msg.message;
        uMsg.wParam := Msg.wParam;
        uMsg.lParam := Msg.lParam;
        DoProcessMsg(uMsg);
        {$ENDIF}
    end;
end;

{//////////////////////////////////////////////////////////////////////////////}
procedure TMsgThread.DoInit;
begin
end;

procedure TMsgThread.DoUnInit;
begin
end;

procedure TMsgThread.DoMsgLoop;
begin
    Sleep(1);
end;

{//////////////////////////////////////////////////////////////////////////////}
procedure TMsgThread.QuitThread;
begin
    {$IFDEF USE_WINDOW_MESSAGE}
    PostMessage(FMSGWin,WM_QUIT,0,0);
    {$ELSE}
    PostThreadMessage(ThreadID,WM_QUIT,0,0);
    {$ENDIF}
end;

{------------------------------------------------------------------------------}
procedure TMsgThread.QuitThreadWait;
begin
    QuitThread;
    WaitTerminate;
end;

{------------------------------------------------------------------------------}
procedure TMsgThread.SetDoLoop(const Value: Boolean);
begin
    if Value = fDoLoop then Exit;
    fDoLoop := Value;
    if fDoLoop then
        PostMsg(WM_USER,0,0);
end;

{------------------------------------------------------------------------------}
//Can only call this method in MAIN Thread!!
procedure TMsgThread.WaitTerminate;
var
    xStart:Cardinal;
begin
    xStart:=GetTickCount;
    try
        //EnableWindow(Application.Handle,False);
        while WaitForSingleObject(Handle, 10) = WAIT_TIMEOUT do
        begin
            Application.ProcessMessages;
            if GetTickCount > (xStart + 4000) then
            begin
                TerminateThread(Handle, 0);
                Beep;
                Break;
            end;
        end;
    finally
        //EnableWindow(Application.Handle,True);
    end;
end;

{------------------------------------------------------------------------------}
procedure TMsgThread.PostMsg(Msg: Cardinal; wParam, lParam: Integer);
begin
    {$IFDEF USE_WINDOW_MESSAGE}
    postMessage(FMSGWin,Msg,wParam,lParam);
    {$ELSE}
    EnterCriticalSection(FCtlSect);
    try
        FEventList.Add(nil);
        PostThreadMessage(ThreadID,Msg,wParam,lParam);
    finally
        LeaveCriticalSection(FCtlSect);
    end;
    {$ENDIF}
end;

{------------------------------------------------------------------------------}
procedure TMsgThread.SendMsg(Msg: Cardinal; wParam, lParam: Integer);
{$IFNDEF USE_WINDOW_MESSAGE}
var
    aEvent:PHandle;
{$ENDIF}
begin
    {$IFDEF USE_WINDOW_MESSAGE}
    SendMessage(FMSGWin,Msg,wParam,lParam);
    {$ELSE}
    EnterCriticalSection(FCtlSect);
    try
        New(aEvent);
        aEvent^ := CreateEvent(nil, True, False, nil);
        FEventList.Add(aEvent);
        PostThreadMessage(ThreadID,Msg,wParam,lParam);
    finally
        LeaveCriticalSection(FCtlSect);
    end;
    WaitForSingleObject(aEvent^,INFINITE);
    {$ENDIF}
end;

end.

[align=right]2003-6-22 10:56:00    [/align]

 查看评语»»»   
 2003-6-22 11:02:24   
我参考了一下msdn,还有windows核心编程.
写了一个类来封装这个功能,不知道对不对.
里面使用了两个方法,一个使用一个隐含窗体来处理消息
还有一个是直接使用thread的消息队列来处理,但是这个时候sendmessage无法工作,所以我自己设想了一个方法,虽然不完全达到了要求但是我简单测试了一下,好像还能工作.

切换两种工作方式要修改编译条件
{$DEFINE USE_WINDOW_MESSAGE} 使用隐含窗体来处理消息
{-$DEFINE USE_WINDOW_MESSAGE} 使用线程消息队列来处理消息
.
[align=right] [/align]
 2003-6-22 11:02:54   
还有我想要等待线程开始进行消息循环的时候create函数才返回.但是现在好像还没有这样(用一个事件来处理).只是开始进入了threadexecute函数,线程的create就返回了.可能会出问题.
[align=right] [/align]
 2003-6-23 8:55:22   
通过设置 DoLoop属性可以设定线程是否循环(不阻塞等待消息),这样派生类线程在循环做一些其他事情的同时还可以接受消息. 例如:派生类里面循环发送缓冲区的数据,还可以响应其他线程发送过来的消息(如停止,启动,退出,等等)
[align=right] [/align]
 2003-8-4 10:21:18   
重新修改了一下,现在用起来基本没有问题了。

{-----------------------------------------------------------------------------
 Unit Name: uMsgThread
 Author:    xwing
 eMail :    xwing@263.net ; MSN : xwing1979@hotmail.com
 Purpose:   Thread with message Loop
 History:

 2003-7-15  Write thread class without use delphi own TThread.
 2003-6-19, add function to Send Thread Message.            ver 1.0
            use Event List and waitforsingleObject
            your can use WindowMessage or ThreadMessage
 2003-6-18, Change to create a window to Recving message
 2003-6-17, Begin.
-----------------------------------------------------------------------------}
unit uMsgThread;

interface
{$WARN SYMBOL_DEPRECATED OFF}

{$DEFINE USE_WINDOW_MESSAGE}
uses
    Classes, windows, messages, forms, sysutils;

const
    NM_EXECPROC = $8FFF;
type
    EMsgThreadErr = class(Exception);
   
    TMsgThreadMethod = procedure of object;

    TMsgThread = class
    private
        SyncWindow  : HWND;
        FMethod     : TMsgThreadMethod;
        procedure SyncWindowProc(var Message: TMessage);

    private
        m_hThread   : THandle;
        threadid    : DWORD;

        {$IFDEF USE_WINDOW_MESSAGE}
        FWinName    : string;
        FMSGWin     : HWND;
        {$ELSE}
        FEventList  : TList;
        FCtlSect    : TRTLCriticalSection;
        {$ENDIF}

        FException  : Exception;
        fDoLoop     : Boolean;
        FWaitHandle : THandle;

        {$IFDEF USE_WINDOW_MESSAGE}
        procedure MSGWinProc(var Message: TMessage);
        {$ELSE}
        procedure ClearSendMsgEvent;
        {$ENDIF}

        procedure SetDoLoop(const Value: Boolean);
        procedure Execute;

    protected
        Msg         :tagMSG;

        {$IFNDEF USE_WINDOW_MESSAGE}
        uMsg        :TMessage;
        fSendMsgComp:THandle;
        {$ENDIF}

        procedure HandleException;
        procedure DoHandleException;virtual;

        //Inherited the Method to process your own Message
        procedure DoProcessMsg(var Msg:TMessage);virtual;

        //if DoLoop = true then loop this procedure
        //Your can use the method to do some work needed loop.
        procedure DoMsgLoop;virtual;

        //Initialize Thread before begin message loop
        procedure DoInit;virtual;
        procedure DoUnInit;virtual;

        procedure PostMsg(Msg:Cardinal;wParam:Integer;lParam:Integer);
        //When Use SendMsg method Must not use Synchronize Method in ThreadLoop !!!
        //otherwise will caurse DeadLock
        function SendMsg(Msg:Cardinal;wParam:Integer;lParam:Integer):Integer;

    public
        constructor Create(Loop:Boolean=False;ThreadName: string='');
        destructor destroy;override;

        // Return TRUE if the thread exists. FALSE otherwise
        function ThreadExists: BOOL;

        procedure Synchronize(syncMethod:TMsgThreadMethod);

        function WaitFor:Longword;
        function WaitTimeOut(timeout:DWORD=4000):Longword;

        //postMessage to Quit,and Free(if FreeOnTerminater = true)
        //can call this in thread loop, don't use terminate property.
        procedure QuitThread;

        //just like Application.processmessage.
        procedure ProcessMessage;

        //enable thread loop, no waitfor message
        property DoLoop: Boolean read fDoLoop Write SetDoLoop;

    end;

implementation

function msgThdInitialThreadProc(pv:Pointer):DWORD;stdcall;
var
    obj:TMsgThread;
begin
    obj := TMsgThread(pv);
    obj.execute;
    Result := 0;
end;

{ TMsgThread }
{//////////////////////////////////////////////////////////////////////////////}
constructor TMsgThread.Create(Loop:Boolean;ThreadName:string);
begin
    {$IFDEF USE_WINDOW_MESSAGE}
    if ThreadName <> '' then
        FWinName := ThreadName
    else
        FWinName := 'Thread Window';
    {$ELSE}
    FEventList := TList.Create;
    InitializeCriticalSection(fCtlSect);
    fSendMsgComp := CreateEvent(nil, True, False, nil);
    {$ENDIF}

    FDoLoop := Loop;            //default disable thread loop

    //Create a Window for sync method
    SyncWindow := CreateWindow('STATIC','SyncWindow',WS_POPUP,0,0,0,0,0,0,hInstance,nil);
    SetWindowLong(SyncWindow, GWL_WNDPROC, Longint(MakeObjectInstance(SyncWindowProc)));

    FWaitHandle := CreateEvent(nil, True, False, nil);
    //Create Thread
    m_hThread := CreateThread(nil,0,@msgThdInitialThreadProc,Self,0,threadid);
    if m_hThread = 0 then
        raise EMsgThreadErr.Create('不能创建线程。');
    //Wait until thread Message Loop started    
    WaitForSingleObject(FWaitHandle,INFINITE);
end;

{------------------------------------------------------------------------------}
destructor TMsgThread.destroy;
begin
    if m_hThread <> 0 then
        QuitThread;
    waitfor;

    //Free Sync Window
    DestroyWindow(SyncWindow);
    FreeObjectInstance(Pointer(GetWindowLong(SyncWindow, GWL_WNDPROC)));

    {$IFDEF USE_WINDOW_MESSAGE}
    {$ELSE}
    FEventList.Free;
    DeleteCriticalSection(FCtlSect);
    CloseHandle(fSendMsgComp);
    {$ENDIF}
   
    inherited;
end;

{//////////////////////////////////////////////////////////////////////////////}
procedure TMsgThread.Execute;
var
    mRet:Boolean;
    aRet:Boolean;
begin
{$IFDEF USE_WINDOW_MESSAGE}
    FMSGWin := CreateWindow('STATIC',PChar(FWinName),WS_POPUP,0,0,0,0,0,0,hInstance,nil);
    SetWindowLong(FMSGWin, GWL_WNDPROC, Longint(MakeObjectInstance(MSGWinProc)));
{$ELSE}
    PeekMessage(Msg,0,WM_USER,WM_USER,PM_NOREMOVE); //Force system alloc a msgQueue
{$ENDIF}

    mRet := True;
    try
        DoInit;

        //notify Conctructor can returen.
        SetEvent(FWaitHandle);
        CloseHandle(FWaitHandle);

        while mRet do   //Message Loop
        begin
            if fDoLoop then
            begin
                aRet := PeekMessage(Msg,0,0,0,PM_REMOVE);
                if aRet and (Msg.message <> WM_QUIT) then
                begin
                    {$IFDEF USE_WINDOW_MESSAGE}
                    TranslateMessage(Msg);
                    DispatchMessage(Msg);
                    {$ELSE}
                    uMsg.Msg := Msg.message;
                    uMsg.wParam := Msg.wParam;
                    uMsg.lParam := Msg.lParam;
                    DoProcessMsg(uMsg);
                    {$ENDIF}

                    if Msg.message = WM_QUIT then
                        mRet := False;
                end;
                {$IFNDEF USE_WINDOW_MESSAGE}
                ClearSendMsgEvent;      //Clear SendMessage Event                
                {$ENDIF}
                DoMsgLoop;
            end
            else begin
                mRet := GetMessage(Msg,0,0,0);
                if mRet then
                begin
                    {$IFDEF USE_WINDOW_MESSAGE}
                    TranslateMessage(Msg);
                    DispatchMessage(Msg);
                    {$ELSE}
                    uMsg.Msg := Msg.message;
                    uMsg.wParam := Msg.wParam;
                    uMsg.lParam := Msg.lParam;
                    DoProcessMsg(uMsg);
                    ClearSendMsgEvent;      //Clear SendMessage Event
                    {$ENDIF}
                end;
            end;
        end;
        DoUnInit;
        {$IFDEF USE_WINDOW_MESSAGE}
        DestroyWindow(FMSGWin);
        FreeObjectInstance(Pointer(GetWindowLong(FMSGWin, GWL_WNDPROC)));
        {$ENDIF}
    except
        HandleException;
    end;
end;

{------------------------------------------------------------------------------}
{$IFNDEF USE_WINDOW_MESSAGE}
procedure TMsgThread.ClearSendMsgEvent;
var
    aEvent:PHandle;
begin
    EnterCriticalSection(FCtlSect);
    try
        if FEventList.Count <> 0 then
        begin
            aEvent := FEventList.Items[0];
            if aEvent <> nil then
            begin
                SetEvent(aEvent^);
                CloseHandle(aEvent^);
                Dispose(aEvent);
                WaitForSingleObject(fSendMsgComp,INFINITE);
            end;
            FEventList.Delete(0);
        end;
    finally
        LeaveCriticalSection(FCtlSect);
    end;
end;
{$ENDIF}

{------------------------------------------------------------------------------}
procedure TMsgThread.HandleException;
begin
    FException := Exception(ExceptObject);  //Get Current Exception object
    try
        if not (FException is EAbort) then
            Synchronize(DoHandleException);
    finally
        FException := nil;
    end;
end;

{------------------------------------------------------------------------------}
procedure TMsgThread.DoHandleException;
begin
    if FException is Exception then
        Application.ShowException(FException)
    else
        SysUtils.ShowException(FException, nil);
end;

{//////////////////////////////////////////////////////////////////////////////}
{$IFDEF USE_WINDOW_MESSAGE}
procedure TMsgThread.MSGWinProc(var Message: TMessage);
begin
    DoProcessMsg(Message);
    if Message.Msg < wm_user then
        with Message do
            Result:=DefWindowProc(FMSGWin,Msg,wParam,lParam);
end;
{$ENDIF}

{------------------------------------------------------------------------------}
procedure TMsgThread.DoProcessMsg(var Msg:TMessage);
begin

end;

{------------------------------------------------------------------------------}
procedure TMsgThread.ProcessMessage;
{$IFNDEF USE_WINDOW_MESSAGE}
var
    uMsg:TMessage;
{$ENDIF}
begin
    while PeekMessage(Msg,0,0,0,PM_REMOVE) do
    if Msg.message <> WM_QUIT then
    begin
        {$IFDEF USE_WINDOW_MESSAGE}
        TranslateMessage(Msg);
        DispatchMessage(msg);
        {$ELSE}
        uMsg.Msg := Msg.message;
        uMsg.wParam := Msg.wParam;
        uMsg.lParam := Msg.lParam;
        DoProcessMsg(uMsg);
        {$ENDIF}
    end;
end;

{//////////////////////////////////////////////////////////////////////////////}
procedure TMsgThread.DoInit;
begin
end;

procedure TMsgThread.DoUnInit;
begin
end;

procedure TMsgThread.DoMsgLoop;
begin
    Sleep(0);
end;

{//////////////////////////////////////////////////////////////////////////////}
function TMsgThread.ThreadExists: BOOL;
begin
    if m_hThread = 0 then
        Result := false
    else
        Result := True;
end;

{------------------------------------------------------------------------------}
procedure TMsgThread.QuitThread;
begin
    {$IFDEF USE_WINDOW_MESSAGE}
    PostMessage(FMSGWin,WM_QUIT,0,0);
    {$ELSE}
    PostThreadMessage(ThreadID,WM_QUIT,0,0);
    {$ENDIF}
end;

{------------------------------------------------------------------------------}
procedure TMsgThread.SetDoLoop(const Value: Boolean);
begin
    if Value = fDoLoop then Exit;
    fDoLoop := Value;
    if fDoLoop then
        PostMsg(WM_USER,0,0);
end;

{------------------------------------------------------------------------------}
function TMsgThread.WaitTimeOut(timeout:dword):Longword;
var
    xStart:Cardinal;
    H: THandle;
begin
    H := m_hThread;
    xStart:=GetTickCount;
    while WaitForSingleObject(h, 10) = WAIT_TIMEOUT do
    begin
        Application.ProcessMessages;
        if GetTickCount > (xStart + timeout) then
        begin
            TerminateThread(h, 0);
            Break;
        end;
    end;
    GetExitCodeThread(H, Result);    
end;

{------------------------------------------------------------------------------}
function TMsgThread.WaitFor: Longword;
var
    Msg: TMsg;
    H: THandle;
begin
    H := m_hThread;
    if GetCurrentThreadID = MainThreadID then
        while MsgWaitForMultipleObjects(1, H, False, INFINITE, QS_SENDMESSAGE) = WAIT_OBJECT_0 + 1 do
            PeekMessage(Msg, 0, 0, 0, PM_NOREMOVE)
    else
        WaitForSingleObject(H, INFINITE);
    GetExitCodeThread(H, Result);
end;

{------------------------------------------------------------------------------}
procedure TMsgThread.PostMsg(Msg: Cardinal; wParam, lParam: Integer);
begin
    {$IFDEF USE_WINDOW_MESSAGE}
    postMessage(FMSGWin,Msg,wParam,lParam);
    {$ELSE}
    EnterCriticalSection(FCtlSect);
    try
        FEventList.Add(nil);
        PostThreadMessage(ThreadID,Msg,wParam,lParam);
    finally
        LeaveCriticalSection(FCtlSect);
    end;
    {$ENDIF}
end;

{------------------------------------------------------------------------------}
function TMsgThread.SendMsg(Msg: Cardinal; wParam, lParam: Integer):Integer;
{$IFNDEF USE_WINDOW_MESSAGE}
var
    aEvent:PHandle;
{$ENDIF}
begin
    {$IFDEF USE_WINDOW_MESSAGE}
    Result := SendMessage(FMSGWin,Msg,wParam,lParam);
    {$ELSE}
    EnterCriticalSection(FCtlSect);
    try
        New(aEvent);
        aEvent^ := CreateEvent(nil, True, False, nil);
        FEventList.Add(aEvent);
        PostThreadMessage(ThreadID,Msg,wParam,lParam);
    finally
        LeaveCriticalSection(FCtlSect);
    end;
    WaitForSingleObject(aEvent^,INFINITE);
    Result := uMsg.Result;
    SetEvent(fSendMsgComp);
    {$ENDIF}
end;

{------------------------------------------------------------------------------}
procedure TMsgThread.Synchronize(syncMethod: TMsgThreadMethod);
begin
    FMethod := syncMethod;
    SendMessage(SyncWindow,NM_EXECPROC,0,Longint(Self));
end;

{------------------------------------------------------------------------------}
procedure TMsgThread.SyncWindowProc(var Message: TMessage);
begin
    case Message.Msg of
        NM_EXECPROC:
        with TMsgThread(Message.lParam) do
        begin
            Message.Result := 0;
            try
                FMethod;
            except
                raise EMsgThreadErr.Create('执行同步线程方法错误。');
            end;
        end;
        else
            Message.Result:=DefWindowProc(SyncWindow,Message.Msg,Message.wParam,Message.lParam);
    end;
end;

end.
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