关于串口通信的问题

Question

大家好我一直用dephi做mis 开发，单位很多考勤软件都是买的，最近领导让做一个读卡器，可是我一点经验都没有。比如考勤软件，如何一刷卡就把数据从库中调用出来。另外如何把卡中的信息写入数据库

Answer 1

http://www.56kc.com/technology/chuangkou.htmhttp://soft.56kc.com/FileDown.aspx?FID=386

Answer 2

控件：
http://soft.56kc.com/Filedown.aspx?FID=167

Answer 3

unit Unit1;interfaceuses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, ComCtrls,Registry;
  
const
    WM_COMMNOTIFY=WM_USER+1;  //通信消息
type
  TForm1 = class(TForm)
    Label4: TLabel;
    RichEdit1: TRichEdit;
    Button1: TButton;
    Button2: TButton;
    Button3: TButton;
    Button4: TButton;
    Button5: TButton;
    Label2: TLabel;
    Label1: TLabel;
    OpenDialog1: TOpenDialog;
    Button6: TButton;
    Memo1: TMemo;
    Label3: TLabel;
    Button7: TButton;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
    procedure Button4Click(Sender: TObject);
    procedure Button5Click(Sender: TObject);
    procedure Button6Click(Sender: TObject);
    procedure Button7Click(Sender: TObject);
  private
    { Private declarations }
    procedure WMCOMMNOTIFY(var Message:TMessage);
    message WM_COMMNOTIFY;
  public
    { Public declarations }
  end;var
  Form1: TForm1;implementation
{$R *.dfm}
var
    hNewCommFile,Post_Event:THandle;
    Read_os:Toverlapped;
    Receive:boolean;
    ReceiveData:Dword;//接收的数据送入显示区
procedure AddToMemo(str:PChar;len:Dword);
begin
    str[len]:=#0;
    Form1.RichEdit1.Text:=Form1.RichEdit1.Text+strpas(str);
end;//通信监视线程
procedure CommWatch(Ptr:Pointer);stdcall;
var
    dwEvtMask,dwTranser:Dword;
    OK:boolean;
    Os:Toverlapped;
begin
    Receive:=True;
    FillChar(Os,sizeof(Os),0);
    Os.hEvent:=CreateEvent(nil,true,false,nil);
    //创建重叠读事件对象
    if os.hEvent=null then
        begin
            MessageBox(0,'Os.Event Creat Erro!','Notice',MB_OK);
            exit;
        end;
    if(not SetCommMask(hNewCommFile,EV_RXCHAR)) then
        begin
            MessageBox(0,'SetCommMask Error!','Notice',MB_OK);
            exit;
        end;
    while(Receive) do
        begin
            dwEvtMask:=0;
            //等待设置好的通信事件发生，由于有个Os（Os：Toverlapped），表示
            //进行的是overlapped等待，不会被这个等待堵塞住
            if not WaitCommEvent(hNewCommFile,dwEvtMask,@Os) then
                begin
                    if ERROR_IO_PENDING=GetLastError then
                        GetOverLappedResult(hNewCommFile,Os,dwTranser,True)
                end;
            if ((dwEvtMask and EV_RXCHAR)=EV_RXCHAR) then
                begin
                    WaitForSingleObject(Post_event,INFINITE);
                    //等待允许传递WM_COMMNOTIFY通信消息
                    ResetEvent(Post_Event);
                    //处理WM_COMMNOTIFY消息，不再发生WM_COMMNOTIFY消息
                    OK:=PostMessage(Form1.Handle,WM_COMMNOTIFY,hNewCommFile,0);
                    //传递WM_COMMNOTIFY通信消息
                    if(not OK) then
                        begin
                            MessageBox(0,'PostMessage Error!','Notice',MB_OK);
                            exit;
                        end;
                end;
            end;
    CloseHandle(Os.hEvent);
end;
{ TForm1 }
//消息处理函数
procedure TForm1.WMCOMMNOTIFY(var Message: TMessage);
var
    CommState:ComStat;
    dwNumberOfBytesRead:Dword;
    ErrorFlag:Dword;
    InputBuffer:array[0..1024] of char;
begin
    //ClearCommError回复通信错误信息并报告当前的通信设备状态。当通信错误发生
    //时调用此函数，他会清除附加的I/O操作的设备错误标志
    if not ClearCommError(hNewCommFile,ErrorFlag,@CommState) then
        begin
            MessageBox(0,'ClearcommErro!','Notice',MB_OK);
            PurgeComm(hNewCommFile,Purge_Rxabort or Purge_Rxclear);
            exit;
        end;
    if(Commstate.cbInQue >0) then
        begin
            fillchar(InputBuffer,CommState.cbInQue,#0);
            //接收通信数据
            if(not ReadFile(hNewCommFile,InputBuffer,CommState.cbInQue,
                                dwNumberOfBytesRead,@Read_Os)) then
                begin
                    ErrorFlag:=GetLastError();
                    if(ErrorFlag<>0) and (ErrorFlag<>ERROR_IO_PENDING) then
                        begin
                            MessageBox(0,'ReadFile Error!','Notice',MB_OK);
                            Receive:=False;
                            CloseHandle(Read_Os.hEvent);
                            CloseHandle(Post_Event);
                            CloseHandle(hNewCommFile);
                            exit;
                        end
                    else
                        begin
                            WaitForSingleObject(hNewCommFile,INFINITE);
                            //等待操作完成，等待设置好的Event的发送
                            GetOverlappedResult(hNewCommFile,Read_Os,
                                                dwNumberOfBytesRead,false);
                        end;
                    end;
                if dwNumberOfBytesRead>0 then
                    begin
                        Read_Os.Offset:=Read_Os.Offset+dwNumberOfBytesRead;
                        ReceiveData:=Read_Os.Offset ;
                        AddToMemo(InputBuffer,dwNumberOfBytesRead);
                        //处理接收的数据
                    end;
        end;
    SetEvent(Post_Event);
    //允许发送下一个WM_COMMNOTIFY消息 
end;//打开文件用于发送
procedure TForm1.Button1Click(Sender: TObject);
begin
    if OpenDialog1.Execute then
        begin
            Button3.Enabled:=false;
            button4.Enabled:=false;
            richedit1.Lines.LoadFromFile(OpenDialog1.FileName );
            form1.Caption:=IntToStr(Richedit1.GetTextLen);
        end;    button1.Enabled:=false;
end;

Answer 4

接上：
//发送数据
procedure TForm1.Button2Click(Sender: TObject);
var
    dcb:TDCB;
    Error:boolean;
    dwNumberOfBytesWritten,dwNumberOfBytesToWrite,ErrorFlag,
    dwWhereToStartWriting:DWORD;
    pDataToWrite:PChar;
    Write_Os:Toverlapped;
begin
    form1.Caption:='';
    hNewCommFile:=CreateFile('COM1',GENERIC_WRITE,0,nil,OPEN_EXISTING,
            FILE_FLAG_OVERLAPPED,0);
    //打开通信端口com5
    if hNewCommFile=INVALID_HANDLE_VALUE then
        MessageBox(0,'Error opening com port!','Notice',MB_OK);    //设置缓冲区大小及主要通信参数
    SetupComm(hNewCommFile,1024,1024);    GetCommState(hNewCommFile,dcb);
    //设置com口的data control block 的属性
    dcb.BaudRate:=9600;
    dcb.ByteSize:=8;
    dcb.Parity:=NOPARITY;
    dcb.StopBits:=ONESTOPBIT;
    Error:=SetCommState(hNewCommFile,dcb);
    if (not Error) then
        MessageBox(0,'SetCommState Error!','Notice',MB_OK);
    dwWhereToStartWriting:=0;
    dwNumberOfBytesWritten:=0;
    dwNumberofBytesToWrite:=richedit1.GetTextLen;
    if(dwNumberOfBytesToWrite=0) then
        begin
            ShowMessage('Text Buffer is Empty!');
            exit;
        end
    else
        begin
            pDataToWrite:=StrAlloc(dwNumberOfBytesToWrite+1);
            try
                richedit1.GetTextBuf(pDataToWrite,dwNumberOfBytesToWrite);
                //label1.Font.Color:=clread;
                fillchar(Write_Os,sizeof(Write_Os),0);
                //为重叠写创建事件对象
                Write_Os.hEvent:=CreateEvent(nil,True,False,nil);
                SetCommMask(hNewCommFile,EV_TXEMPTY);
                //用来表示对EV_TXEMPTY事件感兴趣，有char来到的时候系统会通知
                label1.Caption:='正在发送数据...!';
                repeat
                    label1.Repaint;
                    //发送通信数据
                    if not WriteFile(hNewCommFile,pDataToWrite[dwWhereToStartWriting],
                        dwNumberOfBytesToWrite,dwNumberOfBytesWritten,@Write_Os) then
                        begin
                            ErrorFlag:=GetLastError;
                            if ErrorFlag<>0 then
                                begin
                                    if ErrorFlag=ERROR_IO_PENDING then
                                        begin
                                            //等待设置好的Event的发生
                                            WaitForSingleObject(Write_Os.hEvent,INFINITE);
                                            GetOverlappedResult(hNewCommFile,Write_Os,dwNumberOfBytesWritten,false);
                                        end
                                    else
                                        begin
                                            MessageBox(0,'WriteFile Error!','Notice',MB_OK);
                                            Receive:=false;
                                            CloseHandle(Read_Os.hEvent);
                                            CloseHandle(Post_Event);
                                            CloseHandle(hNewCommFile);
                                            exit;
                                        end;
                                end;
                        end;
                    Dec(dwNumberOfBytesToWrite,dwNumberOfBytesWritten);
                    Inc(dwWhereToStartWriting,dwNumberOfBytesWritten);
                //写整个事情
                until(dwNumberOfBytesToWrite<=0);
                Form1.Caption:=inttostr(dwWhereToStartWriting);
            finally
                strDispose(pDataToWrite);
            end;
            closeHandle(hNewCommFile);
        end;
    Label1.font.color:=clBlack;
    label1.caption:='发送成功！';
    button1.enabled:=true;
    button3.enabled:=true;
    button4.enabled:=true;
end;//接收处理
procedure TForm1.Button3Click(Sender: TObject);
var
    Ok:boolean;
    dcb:TDCB;
    com_thread:Thandle;
    ThreadId:DWORD;
begin
    ReceiveData:=0;
    Button1.Enabled:=false;
    button2.Enabled:=false;
    richedit1.Clear;
    //open com2
    hNewCommFile:=CreateFile('COM2',GENERIC_READ,0,nil,OPEN_EXISTING,
                            FILE_FLAG_OVERLAPPED,0);
    if hNewCommFile=INVALID_HANDLE_VALUE then
        begin
            MessageBox(0,'open com error','Notice',MB_OK);
            exit;
        end;    //指定串行口事件为接收到字符
    OK:=SetCommMask(hNewCommFile,EV_RXCHAR);
    if (not OK) then
        begin
            MessageBox(0,'SetCommMask Error!','Notice',MB_OK);
            exit;
        end;
    //设置缓冲区大小及主要通信参数
    setupComm(hNewCommFile,1024,1024);
    GetCommState(hNewCommFile,dcb);
    dcb.BaudRate:=9600;
    dcb.ByteSize:=8;
    dcb.Parity:=NOPARITY;
    dcb.StopBits:=ONESTOPBIT;
    OK:= SetCommState(hNewCommFile,dcb);
    if(not Ok) then
        MessageBox(0,'SetCommState Error!','Notice',MB_OK);
    fillchar(Read_Os,sizeof(Read_Os),0);
    Read_Os.Offset:=0;
    Read_Os.OffsetHigh:=0;
    //创建overlapped read 事件
    Read_Os.hEvent:=CreateEvent(nil,true,false,nil);
    if Read_os.hEvent =null then
        begin
            CloseHandle(hNewCommFile);
            MessageBox(0,'CreateEvent Error!','Notice',MB_OK);
            exit;
        end;
    //创建PostMessage事件
    Post_Event:=CreateEvent(nil,true,true,nil);
    if Post_Event=null then
        begin
            CloseHandle(hNewCommFile);
            closeHandle(Read_Os.hEvent);
            messageBox(0,'CreateEvent Error','Notice',MB_OK);
            exit;
        end;
    Com_Thread:=CreateThread(nil,0,@CommWatch,nil,0,ThreadID);
    //建立通信监视线程
    if(Com_Thread=0) then
        MessageBox(Handle,'CreateThread 函数不起作用!','Notice',MB_OK);
    EscapeCommFunction(hNewCommFile,SETDTR);
    label1.Font.Color:=clred;
    label1.Caption:='正在接收数据...';
end;//停止通信处理
procedure TForm1.Button4Click(Sender: TObject);
begin
    label1.Font.Color:=clBlack;
    label1.Caption:='已停止通信';
    form1.Caption:=inttostr(ReceiveData);
    Receive:=false;end;procedure TForm1.Button5Click(Sender: TObject);
begin
    close;
end;procedure TForm1.Button6Click(Sender: TObject);
var
  reg : TRegistry;
  ts : TStrings;
  i : integer;
begin
  reg := TRegistry.Create();
  reg.RootKey := HKEY_LOCAL_MACHINE;
  reg.OpenKey('HARDWARE\DEVICEMAP\SERIALCOMM\',false);
  ts := TStringList.Create();
  reg.GetValueNames(ts);
  Memo1.Clear;
  for i := 0 to ts.Count -1 do
    begin
        Memo1.Lines.Add(reg.ReadString(ts.Strings[i]));
    end;
  ts.Free;
  reg.CloseKey;
  reg.free;
end;procedure TForm1.Button7Click(Sender: TObject);
begin
    while (1=1) do
        Label3.Caption :=inttostr(strtoint(Label3.Caption)+1);
end;end.

Answer 5

jpyc(九品-一天帮一位兄弟解决一个问题) 的很好，我用过。很多兄弟都用过了。