Question

帮忙讲解一下这个Delphi程序

TForm1 = class(TForm)
Edit1: TEdit;
Label1: TLabel;
Label2: TLabel;
Label3: TLabel;
ListBox1: TListBox;
BtnPing: TButton;
BtnClearText: TButton;
BtnUseThread: TBitBtn;
ICMP: TIdIcmpClient;
SpinEdit1: TSpinEdit;
procedure BtnUsedThreadClick(Sender: TObject);
procedure ICMPReply(ASender:TComponent;const AReplyStatus:TReplyStatus);
procedure BtnpingClick(Sender: TObject);
procedure BtnClearTextClick(Sender: TObject);

function MyThreadFunc(P:pointer ):Longint;
var icmp: TIdIcmpClient;
begin
ICMP := TIdIcmpClient.Create(nil);
ICMP.Host := form1.Edit1.Text ;
ICMP.ReceiveTimeout := 500;
ICMP.OnReply := Form1.ICMPReply;
ICMP.Ping;
end;

procedure TForm1.BtnUsedThreadClick(Sender: TObject);
var
hThread:Thandle;
ThreadID:DWord;
i:integer ;
begin //创建线程，同时线程函数被调用
for i := 1 to spinedit1.Value do
begin
hthread:=CreateThread(nil,0,@MyThreadfunc,nil,0,ThreadID) ;
end;
if hThread=0 then
messagebox(Handle,'Didn''t CreateaThread',nil,MB_OK);
end;

procedure TForm1.ICMPReply(ASender: TComponent;
const AReplyStatus: TReplyStatus);
var i:integer;
Vreplytype:TReplyStatusTypes;
Begin
Vreplytype:= AReplyStatus.ReplyStatusType ;
case Vreplytype of
rsEcho : listbox1.Items.Add( '收到目标主机的应答');
rsError : listbox1.Items.Add( '数据包错误');
rsTimeOut : listbox1.Items.Add( '发送数据包超时');
rsErrorUnreachable : listbox1.Items.Add( '该数据包无法送达目标主机');
rsErrorTTLExceeded : listbox1.Items.Add( '在传送数据包时，超过其生存时间，该数据包被丢弃');
end;
listbox1.Items.Add('发送应答的主机IP地址： '+AReplyStatus.FromIpAddress);
listbox1.Items.Add('收到的字节数：'+inttostr(AReplyStatus.BytesReceived));
listbox1.Items.Add('生存时间（TTL）：'+inttostr(AReplyStatus.TimeToLive));
listbox1.Items.Add('ICMP报文类型代码: '+inttostr(AReplyStatus.MsgType));
listbox1.Items.Add('ICMP报文标识: '+inttostr(AReplyStatus.SequenceId));
listbox1.Items.Add('ICMP报文往返时间(ms): '+inttostr(AReplyStatus.MsRoundTripTime));
listbox1.Items.Add('*******');
end;

procedure TForm1.BtnPingClick(Sender: TObject);
var i:integer;
begin
form1.ICMP.Host:=form1.Edit1.Text ;
form1.ICMP.ReceiveTimeout:=500;
for i:=1 to spinedit1.value do form1.ICMP.Ping;
end;

procedure TForm1.BtnClearTextClick(Sender: TObject);
begin
listbox1.Items.Clear;
end;
end.
帮忙详细讲解一下

Answer 1

大概是向某主机发送ICMP数据包的程序