My.Settings 中自定义类的数组列表

我有一个 Visual Basic .Net 2.0 程序。我正在将设置从较旧的设置文件移至 app.config 程序设置文件。我正在努力尽可能地做好这件事。

所以，我添加了我的设置如图所示 https://i.stack.imgur.com/eL0aa.png.

加载时我这样做：

If My.Settings.databaseConnectionSettings Is Nothing Then
            My.Settings.databaseConnectionSettings = New ArrayList()
End If

这是我的自定义类：

Imports System.Xml.Serialization

<Serializable()> Public Class DatabaseConnectionSettings
    Private _nickname As String = String.Empty
    Private _username As String = String.Empty
    Private _password As String = String.Empty
    Private _database As String = String.Empty
    Private _server As String = String.Empty
    Private _ssl As Boolean

    Public Sub New()
        _nickname = ""
        _username = ""
        _password = ""
        _database = ""
        _server = ""
        _ssl = False
    End Sub

    Public Sub New(ByVal nickname As String, ByVal username As String, _
                   ByVal password As String, ByVal database As String, _
                   ByVal server As String, ByVal ssl As Boolean)
        _nickname = nickname
        _username = username
        _password = password
        _database = database
        _server = server
        _ssl = ssl
    End Sub

    Public Property nickname() As String
        Get
            Return _nickname
        End Get
        Set(ByVal Value As String)
            _nickname = Value
        End Set
    End Property

    Public Property username() As String
        Get
            Return _username
        End Get
        Set(ByVal Value As String)
            _username = Value
        End Set
    End Property

    Public Property password() As String
        Get
            Return _password
        End Get
        Set(ByVal Value As String)
            _password = Value
        End Set
    End Property

    Public Property database() As String
        Get
            Return _database
        End Get
        Set(ByVal Value As String)
            _database = Value
        End Set
    End Property

    Public Property server() As String
        Get
            Return _server
        End Get
        Set(ByVal Value As String)
            _server = Value
        End Set
    End Property

    <XmlElementAttribute(ElementName:="ssl")> Public Property ssl() As Boolean
        Get
            Return _ssl
        End Get
        Set(ByVal Value As Boolean)
            _ssl = Value
        End Set
    End Property

End Class

而且，这就是我使用它的方式：

Dim databaseSettings As New DatabaseConnectionSettings( _
                        Me.txtNickName.Text, Me.txtUser.Text, Me.txtPass.Text, Me.txtData.Text, _
                            Me.txtServer.Text, Me.chkSSL.Checked)
                        'This statement will increment the arraylist count'
                        My.Settings.databaseConnectionSettings.Add(databaseSettings)
                        'This statement will save everything but the array list'
                        My.Settings.Save()
                        'This statement reloads everything, but the array list.  The array list count after this goes to zero.'
                        My.Settings.Reload() 'If I remove this, program works fine until next run.'

所以，问题是，如何将 DatabaseConnectionSettings 的数组列表保存到持久存储中？我想以尽可能最干净的方式做到这一点。也就是说，我不想每次使用它时都必须将其转换为字符串或将其保存到单独的文件中。我希望能够使用 My.Settings 访问器方法。

请注意，它工作正常，只是没有保存到存储中。

调试 + 异常，勾选 CLR 异常的抛出框。现在您将看到出了什么问题。有几个例外，但破坏交易的是第二个，“这种类型……不是预期的”。

需要属性来告诉 xml 序列化器 ArrayList 中存储的类型。这在本节中有描述MSDN 库页面 http://msdn.microsoft.com/en-us/library/2baksw0z%28VS.71%29.aspx，“序列化 ArrayList”部分。问题是，您无法应用所需的 [XmlElement] 属性，因为 ArrayList 实例是在自动生成的代码中声明的。泛型 List(Of T) 不存在相同的问题，但现在您会遇到设置设计器中的限制，它不支持泛型类型。

好吧，这里进退两难，你无法完成这项工作。 StringCollection 是令人讨厌的替代方案。或者放弃使用 Settings 的想法，直接使用 xml 序列化来完成。或者任何你喜欢的其他东西。