Computer Programming Concepts and Visual Basic David I. Schneider

A Case Study: Recording Checks and Deposits 235
Private Sub cmdRecord_Click()
Dim amt As String, amount As Single, itemNum As Integer
‘Check to ensure all required fields are filled
If AllDataGiven Then
amt = txtAmount.Text ‘Amount of transaction as string
amount = Val(amt) ‘Amount of transaction as number
amt = FormatCurrency(amt) itemNum = Val(txtNum.Text)
If transType = “Check” Then
curBal = curBal - amount
lastCkNum = itemNum
Else ‘transType = “Deposit”
curBal = curBal + amount
lastDpNum = itemNum
End If
lblBalance.Caption = FormatCurrency(curBal)
Open fileName For Append As #1
Write #1, transType, txtToFrom.Text, curBal, lastCkNum, lastDpNum, amt, _
txtMemo.Text, txtDate.Text
Close #1
Call InitializeFields
txtToFrom.SetFocus
End If
End Sub
Private Sub CreateDataFile()
Dim startBal As Single, ckNum As integer
‘The first time the program is run, create a data file
Open fileName For Output As #1
nameOnChk = InputBox(“Name to appear on checks:”)
startBal = Val(InputBox(“Starting balance:”))
ckNum = Val(InputBox(“Number of the first check:”))
lastCkNum = ckNum - 1 ‘Number of “last” check written
ckNum = Val(InputBox(“Number of the first deposit slip:”))
lastDpNum = ckNum - 1 ‘Number of “last” deposit slip processed
curBal = startBal ‘Set current balance
‘First record in data file records name to appear on checks
‘plus initial data for account
Write #1, nameOnChk, startBal, lastCkNum, lastDpNum
Close #1
End Sub
Private Sub Form_Load()
Dim drive As String, today As String
‘If no data file exists, create one. Otherwise, open the
‘data file and get the user’s name, last used check and
‘deposit slip numbers, and current balance.
‘In next line adjust drive as necessary drive = “A:”
‘Drive (or path) for data file
fileName = drive & “CHKBOOK.TXT” ‘Program uses one data file
If Dir(fileName) = “” Then
‘Data file does not exist, so create it and obtain initial data
Call CreateDataFile
Else
Call ReadDataFile
End If