【发布时间】：2011-07-29 12:02:12
【问题描述】：
我目前正在使用框架 4.0 为电影院设计一个客户预订系统模型。目前的所有数据都将存储在一个数组中，并且由于它是一个模型，它将保留其（客户名称、票价等...），因为此时不需要永久存储数据。
我有一个 GUI 表单和两个主要类，MainForm.vb 处理应用程序的 I/O 功能，SeatManager.vb 管理要运行以使程序运行的后台方法。每个类的代码如下：-
**MainForm.vb Class**
Public Class MainForm
Private Const m_totalNumberOfSeats As Integer = 60
Private m_seatManager As SeatManager
Public Sub New()
InitializeComponent()
m_seatManager = New SeatManager(m_totalNumberOfSeats)
InitializeGUI()
End Sub
''' <summary>
''' Method called from the MainForm() method. This method is called when the form
''' is opened by the program (on initialisation).
''' </summary>
Private Sub InitializeGUI()
rbtnReservation.Checked = True 'Sets the Reserve button as being chosen
lstReservations.Items.Clear() 'Clears the list displaying all seats and reservations
txtCustomerName.Text = String.Empty 'Sets the name textbox as emtpy
txtSeatPrice.Text = String.Empty
cmbDisplayOptions.Items.AddRange([Enum].GetNames(GetType(SeatManager.DisplayOptions)))
cmbDisplayOptions.SelectedIndex = SeatManager.DisplayOptions.AllSeats
For i As Integer = 0 To m_totalNumberOfSeats - 1
lstReservations.Items.Add(GetMyString(i))
Next
End Sub
Private Function GetMyString(ByVal i As Integer) As String
If i >= 0 AndAlso i < m_totalNumberOfSeats Then
Return String.Format("{0}{1}{2}{3}", GetPaddedString(m_seatManager.MyArray(i, 0), 29), _
GetPaddedString(m_seatManager.MyArray(i, 1), 41), _
GetPaddedString(m_seatManager.MyArray(i, 2), 63), _
m_seatManager.MyArray(i, 3))
Else
Return String.Empty
End If
End Function
Private Function GetPaddedString(ByVal o As Object, ByVal length As Integer) As String
Dim s As String = String.Empty
If o IsNot Nothing Then s = o.ToString()
If s.Length > length Then s = s.Substring(0, length)
Return s.PadRight(length - s.Length)
End Function
'--Event Handler when you change the value of Customer Name/Price
' Dim index As Integer = lstBox.selectedIndex
'm_arrayClass.PopulateArray(index,customerName.text, ctype(price.text,double))
'lstBox.Items(index) = GetMyString(index)
'Private Function CheckSelectedIndex() As Boolean
' If lstReservations.SelectedIndex <= 0 Then
' Return lstReservations.SelectedIndex
' Else
' Return False
' End If
'End Function
''' <summary>
''' Method uses to verify that the user has entered text within the txtName textbox
''' </summary>
''' <param name="name">String variable passing the customer name inputted by the user</param>
''' <returns>True if validation confirms user has entered at least one character in
''' the txtName field otherwise returns False. If returns false, an error message will
''' be displayed to the user</returns>
Private Function ReadAndValidateName(ByRef name As String) As Boolean
If (String.IsNullOrEmpty(txtCustomerName.Text)) Or (String.IsNullOrEmpty(txtCustomerName.Text)) Then
MessageBox.Show("You have not entered a valid customer name. Please try again", _
"Invalid Customer Name", MessageBoxButtons.OK)
txtCustomerName.Focus()
txtCustomerName.SelectAll()
Return False
Else
Return True
End If
End Function
''' <summary>
''' This method calls the GetDouble() method in the InputUtility class to convert the text
''' given by the user in the txtPrice textbox.
''' </summary>
''' <param name="seatPrice">Output parameter receiving the converted value</param>
''' <returns>True if conversion is successful and validates or False. If returns False
''' an error message will be displayed to the user.</returns>
Private Function ReadAndValidatePrice(ByRef seatPrice As Double) As Boolean
If (InputUtility.GetDouble(txtSeatPrice.Text, seatPrice) And (seatPrice >= 0)) Then
Return True
Else
MessageBox.Show("You have not entered a valid price. Please try again", _
"Invalid Price", MessageBoxButtons.OK)
txtSeatPrice.Focus()
txtSeatPrice.SelectAll()
Return False
End If
End Function
''' <summary>
''' This method calls the above two methods (validate name and validate price) and if both return true,
''' this method also returns true. If either of the above two methods are false, this method returns false
''' </summary>
''' <param name="name">Output Parameter - customer name</param>
''' <param name="seatPrice">Output parameter - seat price</param>
''' <returns>Returns true if validates and false if not</returns>
Private Function ReadAndValidateInput(ByRef name As String, ByRef seatPrice As Double) As Boolean
Dim nameResult As Boolean = ReadAndValidateName(name)
Dim priceResult As Boolean = ReadAndValidatePrice(seatPrice)
Return ((nameResult) And (priceResult))
End Function
Private Sub btnExitApplication_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnExitApplication.Click
Dim msgConfirmation As Integer
msgConfirmation = MessageBox.Show("Are You Sure You Wish To Exit This Application?", "WARNING!", _
MessageBoxButtons.YesNo, MessageBoxIcon.Exclamation)
If msgConfirmation = vbYes Then
Application.Exit()
End If
End Sub
End Class
**SeatManager.vb Class**
Public Class SeatManager
Private _array(,) As Object
Dim m_totalNumberOfSeats As Integer
Public Sub New(ByVal maxNumberOfSeats As Integer)
m_totalNumberOfSeats = maxNumberOfSeats
ReDim _array(m_totalNumberOfSeats - 1, 3)
For i As Integer = 0 To m_totalNumberOfSeats - 1
PopulateArray(i, Nothing, 0.0)
Next
End Sub
Public ReadOnly Property MyArray() As Object(,)
Get
Return _array
End Get
End Property
Public Enum DisplayOptions
AllSeats
VacantSeats
ReservedSeats
End Enum
Public Sub PopulateArray(ByVal i As Integer, ByVal CustomerName As String, ByVal Price As Double)
Dim av As String = "Available"
If Not String.IsNullOrEmpty(CustomerName) Then av = "Not Available"
'Did you say this has to be handled in an enum?
_array(i, 0) = i + 1 'Seat Number
_array(i, 1) = av
_array(i, 2) = CustomerName
_array(i, 3) = Price
End Sub
End Class
我现在想要实现的是，我有一个名为 txtCustomerName 的文本框和一个名为 txtPrice 的文本框。当用户在这些框中输入名称和价格并在列表框中选择一个条目 lstReservations 时，我希望状态从可用更改为“已保留”，并将客户名称和价格输入到相应的数组字段中.
有什么建议吗？在此先感谢
【问题讨论】：
-
很遗憾，您在这里给了我们太多代码。你能隔离问题区域，只显示解释问题所需的代码吗？
-
另外，即使你说你不需要持久化数据，我真的建议你研究某种形式的数据持久性，XML 或数据库（SQL Express 和 SQLite 都是免费的）或者其他的东西。使用数组有时会让你发疯，而使用多维数组会让你更疯狂！数据库很容易解决您遇到的问题。如果你要坚持非持久化，那么至少看看
System.Collections下的集合，比如List(Of T)。 -
我同意 Chris：使用 List(of T) 填充代表您的实体（预订类、客户类等）的类实例，而不是二维数组。这将更容易使用，即使对于模型也是如此。