delphi 下多线程 开发opc 客户端

Question

我在delphi 下用自动化接口编写opc 客户端软件。
引入了 OPC DAAutomation 2.0  OPCDAAuto.dlll
按照下面这个网页的方法，能采集到opc服务器的数据。
http://www.cnblogs.com/tekcat/archive/2010/07/06/1771792.html
但是，我想用在多线程方式下。
所有变量都放到多线程方式下生成，但是就是出错，
“应用程序调用一个已为另一线程整理的接口”。随便编程环境不同，但是方法是类似的，帮我问下啊。

Answer 1

主线程调用如下：unit Unit1;interfaceuses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, OPCAutomation_TLB, OleServer, StdCtrls, ExtCtrls;type
  TForm1 = class(TForm)
    opcgrp1: TOPCGroup;
    opcgrps1: TOPCGroups;
    opcsrvr1: TOPCServer;
    btn1: TButton;
    btn2: TButton;
    btn3: TButton;
    edt1: TEdit;
    Timer1: TTimer;
    Button1: TButton;
    procedure btn1Click(Sender: TObject);
    procedure btn2Click(Sender: TObject);
    procedure btn3Click(Sender: TObject);
    procedure Timer1Timer(Sender: TObject);
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;var
  Form1: TForm1;
  Group:OPCGroup;
  testItem:OPCItem;
  OPCItems:string;
  OPCItemsValues:string;implementation{$R *.dfm}procedure TForm1.btn1Click(Sender: TObject);
begin
  //连接OPC
  opcsrvr1.Connect1('S7200.OPCServer','');
  opcsrvr1.OPCGroups.DefaultGroupUpdateRate:=500;
  Group:=opcsrvr1.OPCGroups.Add('MyGroup');
  Group.IsActive:=True;
  testItem:=Group.OPCItems.AddItem('MicroWin.330282A00101.330282A001000101',0);
  //Group.OPCItems.AddItem('MicroWin.330282A00101.330282A001000101',1);
end;procedure TForm1.btn2Click(Sender: TObject);
begin
//断开OPC
  opcsrvr1.OPCGroups.RemoveAll;
  opcsrvr1.Disconnect;
end;procedure TForm1.btn3Click(Sender: TObject);
var
  myvalue,myquality,mytimestamp:OleVariant;
  testItem1:OPCItem;
begin
  //读OPC数据项
  testItem1:=Group.OPCItems.
  testItem1.Read(OPCDevice,myvalue,myquality,mytimestamp);
  edt1.Text:=myvalue;
end;procedure TForm1.Button1Click(Sender: TObject);
begin
  Timer1.Enabled:=True;
end;procedure TForm1.Timer1Timer(Sender: TObject);
var
  myvalue,myquality,mytimestamp:OleVariant;
begin
  //读OPC数据项
  testItem.Read(OPCDevice,myvalue,myquality,mytimestamp);
  edt1.Text:=myvalue;
end;

Answer 2

多线程调用如下
unit Unit1;interfaceuses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, SyncObjs, ComObj, ActiveX,
  Dialogs, OPCAutomation_TLB, OleServer, StdCtrls, ExtCtrls;  type
    TthreadAcquire = class(Tthread)
    private
        OPCSrvr :TOPCServer;
        Group:TOPCGroup;
        testItem:OPCItem;
        strStyle: string;
    protected
        procedure  Execute;override;
    public
        constructor  Create(createsupped: Boolean; Style: String);
        destructor   Destroy; override;
  end;
type
  TForm1 = class(TForm)
    opcsrvr1: TOPCServer;
    btn1: TButton;
    btn2: TButton;
    btn3: TButton;
    edt1: TEdit;
    procedure btn1Click(Sender: TObject);
    procedure btn3Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;var
  Form1: TForm1;
  Acquire_A: TthreadAcquire;
  CS: TRTLCriticalSection;
implementation{$R *.dfm}
{二、数据采集}
constructor TthreadAcquire.Create(Createsupped: Boolean; Style :string);
var
   i: integer;
begin
    FreeOnTerminate:=False;
    strStyle:=Style;
    inherited Create(Createsupped);
    OPCSrvr:= TOPCServer.Create(nil);
    Group:= TOPCGroup.Create(nil);
    OPCSrvr.Connect1('S7200.OPCServer', '');
    OPCSrvr.OPCGroups.DefaultGroupIsActive:=True;
    OPCSrvr.OPCGroups.DefaultGroupUpdateRate:=500;
    Group.ConnectTo(OPCSrvr.OPCGroups.Add('MyGroup_'+strStyle));
    Group.IsActive:=True;
    Group.IsSubscribed:=False;
    Group.OPCItems.AddItem('MicroWin.330282A00101.330282A001000101',1);
end;destructor TthreadAcquire.Destroy;
begin
   opcsrvr.OPCGroups.RemoveAll;
   opcsrvr.Disconnect;
   Group.Free;
   opcsrvr.Free;
   inherited;
end;procedure TthreadAcquire.Execute;
var
  myValue,myQuality,myTimeStamp:OleVariant;
  tempValue:Real;
begin
   inherited;
   CoInitialize(nil);
   while not  terminated do
   begin
      try
         //EnterCriticalSection(CS);
         testItem:=Group.OPCItems.Item(1);
         testItem.Read(OPCDevice,  myValue, myQuality, myTimeStamp);
         tempValue:=testItem.Value;
         Form1.edt1.Text:=IntToStr(3+Strtoint(Form1.edt1.Text));
         Application.ProcessMessages;
      finally
         //LeaveCriticalSection(CS);
      end;
      if not Self.Suspended Then Self.Suspend;
   end;
   CoUnInitialize;
end;
procedure TForm1.btn1Click(Sender: TObject);
begin
  initializeCriticalSection(CS);
  if Acquire_A=nil then  begin Acquire_A:=TThreadAcquire.Create(True, 'A'); end;
end;procedure TForm1.btn3Click(Sender: TObject);
begin
       try
           if Acquire_A<>nil then  begin  if Acquire_A.Suspended then Acquire_A.Resume; end;
       except       end;
end;

Answer 3

给你一段多线程的标准例子看看：
unit uSendThread;interfaceuses
  Classes, SysUtils, Graphics, Forms;type
  TSendThread = class(TThread)
  private
    { Private declarations }
  protected
    procedure Execute; override;
  public
    constructor Create;
  end;implementationuses Main; {引用主窗体，注意下面的注释内容}{ Important: Methods and properties of objects in visual components can only be
  used in a method called using Synchronize, for example,      Synchronize(UpdateCaption);  and UpdateCaption could look like,    procedure TSendThread.UpdateCaption;
    begin
      Form1.Caption := 'Updated in a thread';
    end; }{ TSendThread }constructor TSendThread.Create;
begin
  inherited Create(False);
end;procedure TSendThread.Execute;
begin
  {这里面是你要获取数据的相关代码}
end;end.{在主窗体中引用该线程单元}uses uSendThread;{主窗体中定义的线程变量}
var  
  SendThread:TSendThread;{点击按钮或事件调用该线程：}SendThread:=TSendThread.create;