chatsvr.cpp

网络编程的一些实例

//---------------------------------------------------------------------------
#include <vcl.h>
#pragma hdrstop

#include "chatsvr.h"
//---------------------------------------------------------------------------
#pragma package(smart_init)
#pragma resource "*.dfm"
TAWChatServerForm *AWChatServerForm;
//---------------------------------------------------------------------------
__fastcall TAWChatServerForm::TAWChatServerForm(TComponent* Owner)
	: TForm(Owner)
{
	Application->OnIdle = IdleEventResponse;
	CurrentServerStatus = SS_NOT_RUNNING;
	MainServerSocket->Port = CHAT_SERVER_PORT;
}
//---------------------------------------------------------------------------
void __fastcall TAWChatServerForm::IdleEventResponse(TObject *Sender, bool &Done){
	if (CurrentServerStatus != SS_RUNNING){
		StartStopServerMenuItem->Caption = "&Start";
	} else {
		StartStopServerMenuItem->Caption = "&Stop";
	}
}
//---------------------------------------------------------------------------
void EntryTypeToText(LogEntryType let, AnsiString &text){
	switch(let){
		case LET_WARNING:{
			text = "Warning";
			break;
		}
		case LET_ERROR:{
			text = "Error";
			break;
		}
		case LET_SIGNON:{
			text = "Sign-on";
			break;
		}
		case LET_SIGNOFF:{
			text = "Sign-off";
			break;
		}
		default:{
			text = "Unknown";
			break;
		}
	}
}
//---------------------------------------------------------------------------
void TAWChatServerForm::AddLogEntry(LogEntryType let, AnsiString EntryText){
	TListItem *item = LogEntryListView->Items->Add();

	AnsiString entrytype;
	EntryTypeToText(let, entrytype);
	item->Caption = entrytype;
	item->SubItems->Add(EntryText);
	item->SubItems->Add(TDateTime::CurrentDateTime());
}
//---------------------------------------------------------------------------
void TAWChatServerForm::SetServerStatus(ServerStatus _serverstatus){
	CurrentServerStatus = _serverstatus;
}
//---------------------------------------------------------------------------
void __fastcall TAWChatServerForm::StartStopServerMenuItemClick(TObject *Sender)
{
	AnsiString ss;
	switch(CurrentServerStatus){
		case SS_NOT_RUNNING:{
			MainServerSocket->Open();
			SetServerStatus(SS_RUNNING);
			AddLogEntry(LET_WARNING, "Server started");
			break;
		}
		case SS_RUNNING:{
			MainServerSocket->Close();
			SetServerStatus(SS_NOT_RUNNING);
			AddLogEntry(LET_WARNING, "Server stopped");
			break;
		}
	}
	UpdateStatusBar();
}
//---------------------------------------------------------------------------
void TAWChatServerForm::AddConnectionToListView(TCustomWinSocket *ClientSocket){
	//The first thing the client will send is the user's nickname
	AnsiString UserNickName = "Unknown";

	TListItem *TempItem = ConnectionsListView->Items->Add();

	TempItem->Caption = UserNickName;
	TDateTime CurrentDT(TDateTime::CurrentDateTime());
	TempItem->SubItems->Add(ClientSocket->RemoteHost);
	TempItem->SubItems->Add(CurrentDT);
	TempItem->Data = ClientSocket;
}
//---------------------------------------------------------------------------
TListItem * TAWChatServerForm::ListItemBySocket(TCustomWinSocket *Socket){
	for (int i = 0; i <	ConnectionsListView->Items->Count; i++){
		if (reinterpret_cast<TCustomWinSocket *>(ConnectionsListView->Items->Item[i]->Data) == Socket){
			return ConnectionsListView->Items->Item[i];
		}
	}
	return NULL;
}
//---------------------------------------------------------------------------
void TAWChatServerForm::RemoveConnectionFromListView(TCustomWinSocket *Socket){
	TListItem *item = ListItemBySocket(Socket);
	if (item)
		ConnectionsListView->Items->Delete(item->Index);
}
//---------------------------------------------------------------------------
void TAWChatServerForm::SetUserBySocket(TCustomWinSocket *Socket, const AnsiString &UserNickName){
	TListItem *item = ListItemBySocket(Socket);
	if (item)
		item->Caption = UserNickName;
}
//---------------------------------------------------------------------------
void TAWChatServerForm::GetUserBySocket(TCustomWinSocket *Socket, AnsiString &UserNickName){
	TListItem *item = ListItemBySocket(Socket);
	if (item)
		UserNickName = item->Caption;
	else
		UserNickName = "Unknown";
}
//---------------------------------------------------------------------------
void TAWChatServerForm::UpdateStatusBar(bool DecUse/* = false*/){
	switch(CurrentServerStatus){
		case SS_NOT_RUNNING:{
			AWChatServerStatusBar->SimpleText = "Press start to begin.";
			break;
		}
		case SS_RUNNING:{
			if (DecUse)
				AWChatServerStatusBar->SimpleText = IntToStr(MainServerSocket->Socket->ActiveConnections - 1) + " current connection(s).";
			else
				AWChatServerStatusBar->SimpleText = IntToStr(MainServerSocket->Socket->ActiveConnections) + " current connection(s).";

			break;
		}
	}
}
//---------------------------------------------------------------------------
void __fastcall TAWChatServerForm::MainServerSocketClientConnect(TObject *Sender,
	  TCustomWinSocket *Socket)
{
	Socket->Data = 0;
	AddConnectionToListView(Socket);
	UpdateStatusBar();
}
//---------------------------------------------------------------------------
void TAWChatServerForm::SendNotification(ServerNotification sn, AnsiString additional, TCustomWinSocket *ExcludeSocket){
	AnsiString UserNickName;
	GetUserBySocket(ExcludeSocket, UserNickName);
	switch(sn){
		case SN_LOGON:{
			BroadcastMessage(UserNickName + " just signed on.", ExcludeSocket);
			AddLogEntry(LET_SIGNON, UserNickName);
			break;
		}
		case SN_LOGOFF:{
			BroadcastMessage(UserNickName + " just signed off.", ExcludeSocket);
			AddLogEntry(LET_SIGNOFF, UserNickName);
			break;
		}
		case SN_PUBLIC_MSG:{
			AnsiString msgtosend = "<" + UserNickName + "> " + additional;
			BroadcastMessage(msgtosend, ExcludeSocket);
			break;
		}
	}
}
//---------------------------------------------------------------------------
void __fastcall TAWChatServerForm::MainServerSocketClientDisconnect(TObject *Sender,
	  TCustomWinSocket *Socket)
{
	SendNotification(SN_LOGOFF, "", Socket);
	RemoveConnectionFromListView(Socket);
	UpdateStatusBar(true);
}
//---------------------------------------------------------------------------
void __fastcall TAWChatServerForm::MainServerSocketClientError(TObject *Sender,
	  TCustomWinSocket *Socket, TErrorEvent ErrorEvent, int &ErrorCode)
{
	AddLogEntry(LET_ERROR, "Socket error " + IntToStr(ErrorCode));
	SendNotification(SN_LOGOFF, "", Socket);
	ErrorCode = 0;
	RemoveConnectionFromListView(Socket);
	UpdateStatusBar(true);
}
//---------------------------------------------------------------------------
void TAWChatServerForm::BroadcastMessage(AnsiString Message, TCustomWinSocket *ExcludeSocket){
	for (int i = 0; i < MainServerSocket->Socket->ActiveConnections; i++){
		if (MainServerSocket->Socket->Connections[i] != ExcludeSocket){
			MainServerSocket->Socket->Connections[i]->SendText(Message);
		}
	}
}
//---------------------------------------------------------------------------
void __fastcall TAWChatServerForm::MainServerSocketClientRead(TObject *Sender,
	  TCustomWinSocket *Socket)
{
	AnsiString UserNickName;
	if (!Socket->Data){
		UserNickName = Socket->ReceiveText();
		int index = UserNickName.Pos("\n");
		if (index > 1)
			UserNickName.SetLength(index-1);
		else
			UserNickName = "Unknown or invalid " + IntToStr(Socket->SocketHandle);
		SetUserBySocket(Socket, UserNickName);
		Socket->Data = (void *)1;
		AnsiString loginresponse = UserNickName + ", welcome to a simple chat server.";
		Socket->SendText(loginresponse);
		SendNotification(SN_LOGON, "", Socket);
	} else {
		AnsiString recvtxt = Socket->ReceiveText();
		SendNotification(SN_PUBLIC_MSG, recvtxt, Socket);
	}
}
//---------------------------------------------------------------------------
void __fastcall TAWChatServerForm::Exit1Click(TObject *Sender)
{
	Close();	
}
//---------------------------------------------------------------------------