大家好，我有两个串口程序不太明白，能帮忙解决一下吗？
一：
unit Unit1;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, Buttons, StdCtrls, OleCtrls, MSCommLib_TLB;
type
TCommForm = class(TForm)
Label1: TLabel;
memDisplay: TMemo;
Label2: TLabel;
Label3: TLabel;
edtCommport: TEdit;
edtCommsetting: TEdit;
OpenDialog1: TOpenDialog;
SaveDialog1: TSaveDialog;
MSComm1: TMSComm;
Display: TLabel;
Button1: TButton;
BitBtn1: TBitBtn;
StaticText1: TStaticText;
procedure FormCreate(Sender: TObject);
procedure Button1Click(Sender: TObject);
procedure MSComm1Comm(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;
var
CommForm: TCommForm;
Receiver:TObject;
Display:TObject;
ss,caption:string;
savef,readf:file of char;
i,j:longint;
implementation
{$R *.dfm}
//初始化
procedure TCommForm.FormCreate(Sender: TObject);
begin
MSComm1.commport:=1;
MSComm1.settings:='9600,N,8,1'; //将通信口设置为9600bit/s，无奇偶校验，8个数据位，1个停止位
MSComm1.inputlen:=1;
MSComm1.inbuffercount:=0;
MSComm1.portopen:=true;
ss:='';
i:=0;
j:=0;
assignfile(savef,SaveDialog1.FileName);
rewrite(savef);
assignfile(readf,OpenDialog1.FileName);
reset(readf);
end;
//设置确定
procedure TCommForm.Button1Click(Sender: TObject);
begin
if MSComm1.portopen then
MSComm1.portopen:=false;
MSComm1.commport:=StrToInt(edtCommport.text);
MSComm1.settings:=edtCommsetting.Text;
end;
procedure TCommForm.MSComm1Comm(Sender: TObject);
var
filenrc:char;
buffer:variant;
s1:string;
c:char;
begin
case MSComm1.commEvent of
comEvSend:
begin
while not(eof(readf)) do
begin
read(readf,filenrc);
MSComm1.output:=filenrc;
j:=j+1;
Display.caption:=inttostr(j);
if MSComm1.OutBufferCount>=2 then
break;
end;
end;
comEvReceive:
begin
buffer:=MSComm1.Input;
s1:=buffer;
c:=s1[1];
ss:=ss+c;
i:=i+1;
Display.caption:=c+inttostr(i);
write(savef,c);
if (c=chr(10))or(c=chr(13)) then
begin
Display.caption:='cr'+IntToStr(i);
memDisplay.lines.add(ss);
ss:='';
end;
end;
end;
end;
end.
上面的程序我看不懂，也不知道它是怎么进行传输的？我不知道怎么操作它，这是书上的一个例子，求各位帮我分析一下
二：
unit Unit1;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls, OleCtrls, MSCommLib_TLB;
type
TForm1 = class(TForm)
Memo1: TMemo;
Label1: TLabel;
ComboBox1: TComboBox;
ComboBox2: TComboBox;
Label2: TLabel;
Label3: TLabel;
Button1: TButton;
Button2: TButton;
MSComm1: TMSComm;
procedure FormCreate(Sender: TObject);
procedure Button1Click(Sender: TObject);
procedure Button2Click(Sender: TObject);
procedure MSComm1Comm(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;
var
Form1: TForm1;
implementation
{$R *.dfm}
procedure TForm1.FormCreate(Sender: TObject);
begin
MSComm1.InBufferCount:=0; //清空接收缓冲区
MSComm1.InputLen:=0; //Input读取整个缓冲区内容
MSComm1.RThreshold:=1; //每次接收到字符即产生OnComm事件
end;
procedure TForm1.Button1Click(Sender: TObject);
begin
MSComm1.Settings:=ComboBox1.Text;
if ComboBox2.Text='COM1' then //假设只考虑COM1和COM2两种情况
MSComm1.CommPort:=1
else
MSComm1.CommPort:=2;
MSComm1.PortOpen:=true; //打开串口
MSComm1.DTREnable:=true; //数据终端准备好
MSComm1.RTSEnable:=true; //请求发送
end;
procedure TForm1.Button2Click(Sender: TObject);
begin
MSComm1.PortOpen:=false; //关闭串口
MSComm1.DTREnable:=false;
MSComm1.RTSEnable:=false;
end;
procedure TForm1.MSComm1Comm(Sender: TObject);
var
recstr:Olevariant;
begin
if MSComm1.CommEvent=2 then
begin
recstr:=MSComm1.Input;
Memo1.Text:=Memo1.Text+recstr;
end;
end;
end.
上面这个程序有一部分不懂，就是：
procedure TForm1.MSComm1Comm(Sender: TObject);
var
recstr:Olevariant;
begin
if MSComm1.CommEvent=2 then
begin
recstr:=MSComm1.Input;
Memo1.Text:=Memo1.Text+recstr;
end;
end;
不知道是什么意思，为什么Comm1.Input＝2呢？
辛苦大家了，谢谢
