mainfrm.pas

《delphi深度编程及其项目开发》

unit Mainfrm;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, Buttons, SPComm, ExtCtrls, ComCtrls;

type
  TfrmComm = class(TForm)
    Comm: TComm;
    StatusBar1: TStatusBar;
    Panel1: TPanel;
    Panel2: TPanel;
    mmoComm: TMemo;
    btnOpen: TBitBtn;
    btnClose: TBitBtn;
    btnSend: TBitBtn;
    Panel3: TPanel;
    edtSendText: TEdit;
    Label6: TLabel;
    Label1: TLabel;
    Label2: TLabel;
    Label3: TLabel;
    Label4: TLabel;
    Label5: TLabel;
    cmbByteSize: TComboBox;
    cmbStopBits: TComboBox;
    cmbParity: TComboBox;
    edtCommName: TEdit;
    edtBaudRate: TEdit;
    procedure btnOpenClick(Sender: TObject);
    procedure btnCloseClick(Sender: TObject);
    procedure btnSendClick(Sender: TObject);
    procedure CommReceiveData(Sender: TObject; Buffer: Pointer;
      BufferLength: Word);
    procedure edtBaudRateExit(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure cmbByteSizeChange(Sender: TObject);
    procedure cmbStopBitsChange(Sender: TObject);
    procedure cmbParityChange(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  frmComm: TfrmComm;
implementation

{$R *.dfm}

//当窗体创建时，初始化参数
procedure TfrmComm.FormCreate(Sender: TObject);
begin
  edtCommName.Text := 'COM1';
  edtBaudRate.Text := '9600';
  cmbByteSize.ItemIndex := 3;
  cmbStopbits.ItemIndex := 0;
  cmbParity.ItemIndex := 0;
end;

//打开端口
procedure TfrmComm.btnOpenClick(Sender: TObject);
begin
  //设置串口参数
  comm.CommName := edtCommName.Text;
  comm.BaudRate := strToInt(edtBaudRate.Text);
  comm.ByteSize := TByteSize(cmbByteSize.ItemIndex);
  comm.StopBits := TStopBits(cmbStopBits.ItemIndex);
  comm.Parity := TParity(cmbParity.ItemIndex);
  //打开串口
  try
    Comm.StartComm;
  except
    raise Exception.Create('打开串口错误');
  end;
  statusbar1.Panels[0].Text := Comm.CommName + '已打开';
  statusbar1.Refresh;
  btnOpen.Enabled := False;
  btnSend.Enabled := True;
  btnClose.Enabled := True;
end;

//关闭端口
procedure TfrmComm.btnCloseClick(Sender: TObject);
begin
  Comm.StopComm;
  statusbar1.Panels[0].Text := Comm.CommName + '已关闭';
  statusbar1.Refresh;
end;


//向端口发送数据
procedure TfrmComm.btnSendClick(Sender: TObject);
var
  str: Pchar;
  Count: integer;
begin
  str := Pchar(edtSendText.Text);
  Count := Length(str);
  if Comm.WriteCommData(str, Count) then
    mmoComm.Lines.Add('已发送' + intTostr(Count) + '个字符')
  else
    raise exception.Create('发送错误');
end;

//从端口接收数据
procedure TfrmComm.CommReceiveData(Sender: TObject; Buffer: Pointer;
  BufferLength: Word);
var
  strRecv : string;
begin
  setLength(strRecv,BufferLength);
  Move(Buffer^,pchar(strRecv)^,BufferLength);
  mmoComm.Lines.Add('已收到：'+intTostr(BufferLength)+'字节的数据');
  mmoComm.Lines.Add(strRecv);
  mmoComm.Invalidate ;
end;

//对波特率进行有效性检验
procedure TfrmComm.edtBaudRateExit(Sender: TObject);
var
  i: integer;
begin
  try
    i := strToInt(edtBaudRate.Text)
  except
    edtBaudRate.setfocus;
    raise Exception.Create('波特率设置错误');
  end;
    //改变串口的波特率
  comm.BaudRate := StrToInt(edtBaudRate.Text);
end;

procedure TfrmComm.cmbByteSizeChange(Sender: TObject);
begin
  //改变串口的数据位
  comm.ByteSize := TByteSize(cmbByteSize.ItemIndex);
end;

procedure TfrmComm.cmbStopBitsChange(Sender: TObject);
begin
  //改变串口的停止位
  comm.StopBits := TStopBits(cmbStopBits.ItemIndex);
end;

procedure TfrmComm.cmbParityChange(Sender: TObject);
begin
  //设置串口的奇偶校验位
  comm.Parity := TParity(cmbParity.ItemIndex);
end;

end.