private void pos_DataReceived(object sender, SerialDataReceivedEventArgs e)
{
string message = ((SerialPort)sender).ReadExisting();
// Debug.WriteLine(BitConverter.ToString(System.Text.Encoding.Default.GetBytes(message))); // Write HEX to the debug
if (message == ("\u0006"))
{
receivedACK = true; // Received ACK, set the flag
}
else if (message == ("\u0015"))
{
receivedNACK = true; // Received NACK, set the flag
}
else if (message.StartsWith("25"))
{
POSPort.Write(((char)0x06).ToString()); // Received HOLD Message, send ACK to confirm the hold
}
else
{
lastPOSMsg = new POSMessage(message); // Received POSMessage, Parse it and assign it to lastPOSMsg
}
}
public SaleResult(bool success, POSMessage lastMessage)
{
this._success = success;
this._lastMessage = lastMessage;
}
public SaleResult Sale(Int64 Amount)
{
if (!_connected)
{
return(new SaleResult(false, null));
}
// Build the message to send to the device
ECRMessage msg = new ECRMessage();
msg.NextTransactionNo = NextTransactionNo;
msg.CurrencyISO = CurrencyISO;
msg.POSPrints = POSPrints;
msg.CashierID = CashierID;
msg.TransactionAmount = Amount;
msg.TransactionType = Consts.TransactionType.SALE;
msg.LanguageID = Language;
// Clear the buffer
POSPort.ReadExisting();
// Send the message to the device
POSPort.Write(msg.Message);
/// To verify that the device got our message, we wait for ACK or 0x06 response
/// If the device got our message, and it was not in correct format, we will get 0x15 as response, which is NACK
/// We have allowed time for the device to get back to us and that, by specification, is 1 second
/// After 1 second we send it the message once again, and hopefully it will receive it this time
/// After 3 tries, the transaction will be marked as unsuccessful, with communication error.
int sendTry = 0;
int ms = 0;
bool success = false;
#region Waiting for ACK/NACK
while (true)
{
if (receivedACK)
{
success = true;
receivedACK = false;
receivedNACK = false;
break;
}
if (receivedNACK)
{
success = false;
receivedACK = false;
receivedNACK = false;
break;
}
if (ms > 1000)
{
ms = 0;
sendTry++;
if (sendTry == 3)
{
break;
}
POSPort.Write(msg.Message);
}
System.Threading.Thread.Sleep(1);
ms++;
}
#endregion Waiting for ACK/NACK
if (!success)
{
return(new SaleResult(false, null));
}
/// After we receive 0x06, we wait for the message on the end of the transaction that tells us
/// wether the transaction was successful or not, and other params such as cause, transaction date, amount, time etc...
#region Waiting for Message
lastPOSMsg = null;
while (lastPOSMsg == null)
{
}
#endregion Waiting for Message
/// Message received, check it and send the response if message is correct and
/// if transaction was successful
if (lastPOSMsg.TransactionFlag == Consts.TransactionFlag.ACCEPTED_WITH_AUTH ||
lastPOSMsg.TransactionFlag == Consts.TransactionFlag.ACCEPTED_WITHOUT_AUTH)
{
// Transaction was successful :D
// Send ACK and return transaction successful
POSPort.Write(((char)0x06).ToString());
}
else if (lastPOSMsg.TransactionFlag == Consts.TransactionFlag.REFUSED ||
lastPOSMsg.TransactionFlag == Consts.TransactionFlag.ERROR ||
lastPOSMsg.TransactionFlag == Consts.TransactionFlag.COMMUNICATION_ERROR)
{
// Transaction wasn't successful :(
// Send ACK and return transaction unsuccessful
POSPort.Write(((char)0x06).ToString());
return(new SaleResult(false, lastPOSMsg));
}
else
{
// Message probably not valid, send NACK
POSPort.Write(((char)0x15).ToString());
return(new SaleResult(false, null));
}
// If everything goes as planned, this lines of code should be executed
NextTransactionNo++;
return(new SaleResult(true, lastPOSMsg));
}
