How to Print Receipt by POS Printer using VB.Net.

In RMS some times we need to print receipt like Sales Receipt, Gift Receipt etc by POS printer. Before printing the receipt we need to make a string with using  escape sequences, that escape sequences recognized by the printer. If an escape sequence specifies an operation that is not supported by the printer station, it is ignored.
Following is the code snippet for printing Gift Receipt by EPSON TM-T88IVP Printer.

************ VB Code *********

Public Sub GiftReceipt()
 
   Try
 
        Dim displayString As String
            
         Dim ESC As String = Chr(&H1B)
 
        displayString = ESC + "!" + Chr(1) + ESC + "|cA" + "Store Name" + ESC + "|1lF"
        displayString += ESC + "|cA" + "Store Address" + ESC + "|1lF"
        displayString += ESC + "|2C" + ESC + "|cA" + ESC + "|bC" + "Gift Receipt" + ESC + "|1lF" + ESC + "|1lF"
        displayString += ESC + "|N" + ESC + "!" + Chr(1) + "  Transaction #:  " + vbTab.ToString() + "105" + ESC + "|1lF"
            
displayString += "  Date:  " + Date.Today() + vbTab.ToString() + "Time: "
            
       displayString += DateAndTime.Now().ToLongTimeString() + ESC + "|1lF"
            
       displayString += "  Cashier:  " + CStr(_currSess.Cashier.Number) + vbTab.ToString() + "Register:  " + CStr(_currSess.Register.Number) + ESC + "|1lF" + ESC + "|1lF"
        
       displayString += ESC + "|2uC" + "  Item                 Description           Quantity" + ESC + "|N" + ESC + "!" + Chr(1) + ESC + "|1lF" + ESC + "|1lF" + "  "
            
        'Iterate loop for each row of the Data Set.
    For k As Integer = 0 To TransactionSet1.TransactionEntry.Rows.Count - 1
 
                'Checking for each row which has selected in DataGrid item.
      If CType(dgTransactionList.Item(k, 0), System.String) = "True" Then
 
                      'Get the Item value from selected row.
          Dim item As String = dgTransactionList.Item(k, 1).ToString()
 
                      Dim itemValue As String = String.Empty
                       If item.Length > 11 Then
   'if Item length is greater then 11, then take substring of item 0 to 11.
                  item = item.Substring(0, 11)
                      Else
                     'Adding " " in Item string until length 11.
                              While item.Length  20 Then
 
      'If Description length is greater then 20, then take substring of item 0 to 20.
                 desc = desc.Substring(0, 20)
 
                    Else
                While desc.Length