在VB.NET 2010中打印

Question

I want to print on a Passbook (paper book used to record bank transactions) using a passbook printer (Epson PLQ 20) Using VB.NET 2010.

My current mysql table structure is,

1. tblLoanRegistry(LoanID pk, EMPNumber, Date, Amount, NoOfInstallments, Teller)
2. tblLoanAccount(ID pk, LoanID fk, Date, Payment, Interest, Total, Auto bool, Installment int, teller)

My problems are:

1. How to detect the last row printed?
2. How to print the first row that not printed, on the correct position of the book (Correct line).

I have decided to add a field "Printed" (Boolean) in each table above mentioned. To get the printed or not. I can print text, numbers etc using the same printer in vb.net (Eg: Account holders details on the front page). But I'm facing above mentioned problems when printing transactions. Your help/ opinions highly appreciated.

More Information: Actually I developed a web based account handling system using php and mysql for a non profit organisation as the my project of the degree. Now they want to print transactions on a passbook as I described before.

Therefore I am creating an application using VB.NET (I am totally new to VB.NET. But have experience in vb6) while I am learning it. I have managed to simple printing but this is something different.

I have no good idea to solve above mentioned two problems.

Update: I did it in different (may be a bad) way. On click event of the print button.

    Dim sqlLoan As String

    conn = New MySqlConnection(cnString)

    sqlLoan = "SELECT tblLoanAccount.Date,if(Installment = 0, 'Interest', concat('Installment : ', Installment)) as Description, tblLoanAccount.Payment, tblLoanAccount.Interest, " &
        " tblLoanAccount.Total, tblLoanAccount.Auto, tblLoanAccount.Installment FROM tblLoanAccount join tblloanRegistry on  tblloanRegistry.LoanID = tblLoanAccount.LoanID " &
        " where(tblloanRegistry.EMPNumber = " & cmbEMPN.Text & " And tblLoanAccount.LoanID = tblLoanRegistry.LoanID) AND tblLoanAccount.Total <> 0 ORDER BY tblLoanAccount.ID"

    Using conn As New MySqlConnection(cnString)
        Using cmd As New MySqlCommand(sqlLoan, conn)
            conn.Open()
            Using myReader As MySqlDataReader = cmd.ExecuteReader()
                Using writer As StreamWriter = New StreamWriter("c:\file.txt")
                    While myReader.Read()
                        writer.WriteLine("{0}, {1}, {2}, {3}, {4}", myReader.Item(0), myReader.Item(1), myReader.Item(2), myReader.Item(3), myReader.Item(4))
                    End While
                End Using
                Call Printing()
            End Using
        End Using
    End Using

    ' Print the file. 
Public Sub Printing()
    Try
        streamToPrint = New StreamReader(("c:\file.txt"))
        Try
            printFont = New Font("Arial", 10)
            Dim pd As New PrintDocument()
            AddHandler pd.PrintPage, AddressOf pd_PrintPage
            ' Print the document.
            pd.Print()
        Finally
            streamToPrint.Close()
        End Try
    Catch ex As Exception
        MessageBox.Show(ex.Message)
    End Try
End Sub 'Printing

And other codes are as msdn PrintDocument Class .

Answer 1

There are a lot of unknowns in this question. For example, when you mark an item as printed, do you want to mark it universally (for all applications, all transactions and all time) or only within a limited context (a particular application, transaction or time frame)?

Is a transaction started and completed within a single .NET thread, or is this application multi-threaded, or does the transaction span across multiple independent executions? Do you need some record of an item having been printed beyond the physical piece of paper?

Assuming you want a record of an item having been printed only within a particular transaction, you may want to create a third table, called something like tblPrintTransaction, with a Primary Key or other identifier column and any additional columns you desire (transaction start date, end date, user ID, contextual information, etc.). When you start your application, create a new row in this table and get the row ID.

Now, create a fourth table, called something like tblPrintTransactionArtifact, with at least two columns. One column will be a foreign key identifying the transaction (from the tblPrintTransaction table) and one or more columns will be used to identify the item that has been printed. For example, your table could contain two columns to identify the printed item: one column specifying either "Registry" or "Account" and another specifying the item's ID.

Of course, all of this information could be created and maintained within the application itself (using variables, etc), but storing them in a table means they will persist beyond the execution of the application, giving you a permanent record. I would recommend that you keep track of the current "line" on the printed page within the application as I see little use for this within your database.

Answer 2

Dim sqlLoan As String

conn = New MySqlConnection(cnString)

sqlLoan = "SELECT tblLoanAccount.Date,if(Installment = 0, 'Interest', concat('Installment : ', Installment)) as Description, tblLoanAccount.Payment, tblLoanAccount.Interest, " &
    " tblLoanAccount.Total, tblLoanAccount.Auto, tblLoanAccount.Installment FROM tblLoanAccount join tblloanRegistry on  tblloanRegistry.LoanID = tblLoanAccount.LoanID " &
    " where(tblloanRegistry.EMPNumber = " & cmbEMPN.Text & " And tblLoanAccount.LoanID = tblLoanRegistry.LoanID) AND tblLoanAccount.Total <> 0 ORDER BY tblLoanAccount.ID"

Using conn As New MySqlConnection(cnString)
    Using cmd As New MySqlCommand(sqlLoan, conn)
        conn.Open()
        Using myReader As MySqlDataReader = cmd.ExecuteReader()
            Using writer As StreamWriter = New StreamWriter("c:\file.txt")
                While myReader.Read()
                    writer.WriteLine("{0}, {1}, {2}, {3}, {4}", myReader.Item(0), myReader.Item(1), myReader.Item(2), myReader.Item(3), myReader.Item(4))
                End While
            End Using
            Call Printing()
        End Using
    End Using
End Using

    ' Print the file. 
Public Sub Printing()
    Try
        streamToPrint = New StreamReader("c:\file.txt")
        Try
            printFont = New Font("Arial", 10)
            Dim pd As New PrintDocument()
            AddHandler pd.PrintPage, AddressOf pd_PrintPage
            ' Print the document.
            pd.Print()
        Finally
            streamToPrint.Close()
        End Try
    Catch ex As Exception
        MessageBox.Show(ex.Message)
    End Try
End Sub 'Printing

And other codes are as msdn PrintDocument Class.

Answer 3

您可以尝试使用我在http://www.jcl.vdtec.net上使用MySql和VB.Net的易于使用的轻量级报表编写器。