Bank Account.Write a program to maintain a person's Savings and Checking accounts. The program should keep track of and display the balances in both accounts, and maintain a list of transactions (deposits, withdrawals, fund transfers, and check clearings) separately for each account. The two lists of transactions should be stored in sequential files so that they will persist between program sessions.
[Page 603]Consider the form in Figure 11.12. The two dropdown combo boxes should each contain the items Checking and Savings. Each of the four group boxes corresponds to a type of transaction. (When Savings is selected in the Account combo box, the Check group box should disappear.) The user makes a transaction by typing data into the text boxes of a group box and pressing the button. The items appearing in the Transactions list box should correspond to the type of account that has been selected. The caption of the second label in the Transfer group box should toggle between "to Checking" and "to Savings" depending on the item selected in the "Transfer from" combo box. If a transaction cannot be carried out, a message (such as "Insufficient funds") should be displayed.
Figure 11.12. Bank accounts.
The program should use two classes, Transaction and Account. The class Transaction should have properties for transaction name, amount, date, and whether it is a credit (deposit) or debit (withdrawal/check).
The class Account, which will have both a checking account and a savings account as instances, should use an array of Transaction objects. In addition, it should have properties for name (Checking or Savings) and balance. It should have methods to carry out a transaction (if possible), to display the list of transactions, and to load and retrieve the set of transactions into or from a sequential file. The events InsufficientFunds and TransactionCommitted should be triggered at appropriate times. A technique for obtaining a string containing today's date can be found in the frmAccount_Load procedure of the case study "Recording Checks and Deposits" in Section 8.3.
Hint: In order for an Account object to display a list of transactions, a list box should be passed to a method as an argument. The method might be declared with Sub EnumerateTransactions(ByVal lb As ListBox).
