我的问题！！！(50分)

如何用双线程作程序，举例，最好有源码。

Delphi自己就有一个排序的例子

94 94 多看看DEMO吧 不要偷懒[]

这里是一段后台线程监听串口代码！

unit frmComm;

interface

uses
Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
StdCtrls, ComCtrls,GeoUtils,GeoGPS;

const MAXBLOCK = 160;

type
TComm = record
idComDev : THandle;
fConnected : Boolean;
end;

TCommForm = class(TForm)
ComboBox1: TComboBox;
Button1: TButton;
StatusBar1: TStatusBar;
Button2: TButton;
ComboBox2: TComboBox;
procedure Button1Click(Sender: TObject);
procedure Button2Click(Sender: TObject);

procedure FormClose(Sender: TObject; var Action: TCloseAction);
private
{ Private declarations }
public
{ Public declarations }
end;

TCommThread = Class(TThread)
protected
procedure Execute;override;
public
constructor Create;
end;

var
CommForm: TCommForm;
CommHandle : THandle;
Connected : Boolean;
CommThread : TCommThread;

implementation

{$R *.DFM}

uses
frmMain,frmMdiMapView;

procedure TCommThread.Execute;
var
dwErrorFlags,dwLength : DWORD;
ComStat : PComStat;
fReadStat : Boolean;
InChar : Char;
AbIn : String;
XX,YY : double; //经度、纬度

VID : string; //车号
begin
while Connected do begin
GetMem(ComStat,SizeOf(TComStat));
ClearCommError(CommHandle, dwErrorFlags, ComStat);
if (dwErrorFlags > 0) then begin
PurgeComm(CommHandle,(PURGE_RXABORT and PURGE_RXCLEAR));
// return 0;
end;
dwLength := ComStat.cbInQue;
if (dwLength>0) then begin
fReadStat := ReadFile(CommHandle, InChar, 1,dwLength, nil);
if (fReadStat) then begin

if (InChar <> Chr(13)) and (Length(abIn) < MAXBLOCK+5 ) then AbIn := AbIn + InChar
else begin
...
{接收完毕，}
end;//if (fReadStat>0){
end; //if (dwLength>0){
FreeMem(ComStat);
end;{while}
end;

constructor TCommThread.Create;
begin
FreeOnTerminate := TRUE;
inherited Create(FALSE); //Createsuspended = false
end;

//
procedure TCommForm.Button1Click(Sender: TObject);
var

CommTimeOut : TCOMMTIMEOUTS;
DCB : TDCB;
fRetVal : Boolean;
begin
StatusBar1.SimpleText := '连接中...';
CommHandle := CreateFile(PChar(ComboBox1.Text),GENERIC_READ,0,nil,OPEN_EXISTING,FILE_ATTRIBUTE_NORMAL
, 0);
if CommHandle = INVALID_HANDLE_VALUE then begin
StatusBar1.SimpleText := '连接失败';
Exit;
end;
StatusBar1.SimpleText := '已同端口 '+ ComboBox1.Text + ' 连接！';
CommTimeOut.ReadIntervalTimeout := MAXDWORD;
CommTimeOut.ReadTotalTimeoutMultiplier := 0;

CommTimeOut.ReadTotalTimeoutConstant := 0;
SetCommTimeouts(CommHandle, CommTimeOut);

GetCommState(CommHandle,DCB);
DCB.BaudRate := 9600;
DCB.ByteSize := 8;
DCB.Parity := NOPARITY;
DCB.StopBits := ONESTOPBIT;
fRetVal := SetCommState(CommHandle, DCB);
if (fRetVal) then begin
Connected := TRUE;
try
CommThread := TCommThread.Create;
except
Connected := FALSE;
CloseHandle(CommHandle);
fRetVal := FALSE;
StatusBar1.SimpleText := '线程建立失败';
Exit;

end;
end
else begin
Connected := FALSE;
CloseHandle(CommHandle);
end;
end;

procedure TCommForm.Button2Click(Sender: TObject);
begin
Connected := FALSE;
CloseHandle(CommHandle);
{终止线程}
CommThread.Terminate;
StatusBar1.SimpleText := '关闭端口'+ComboBox1.Text;
end;

procedure TCommForm.FormClose(Sender: TObject; var Action: TCloseAction);
begin
Connected := FALSE;
CloseHandle(CommHandle);

StatusBar1.SimpleText := '关闭端口'+ComboBox1.Text;
end;

end.