一种简便实效的配置文件读写方法

主要做法：

第一步，将配置信息做一个简单的类。

要点：因为要用到序列化，而且是用XmlSerializer来序列化，所以要存到文件的变量信息都要声明为Public,要序列化的类用修饰。

示例：一个连接数据库的配置信息

'配置信息

Public Class Item

'初始默认值

Public ID As Integer = 0

Public Server As String = "(Local)"

Public Database As String = "NorthWind"

Public Tusted As Boolean = True

Public User As String = ""

Public Password As String = ""

End Class

第二步：配置处理的类。

说明：这个类是通用的。用到别的配置，你只需修改上面的配置信息类就可以了。它实现了存档和读取的功能，并转化为配置信息对象，操作起来较为方便。你可以添加内容加密的处理。

Public Class Config

'默认ConnectionInfo的ID

Public ID As Integer

'必须是Public,XmlSerializer只对Pulbic变量作用

Public Items As Item()

Private m_Count As Integer = 0

'添加配置信息

Public Sub Add(ByVal ConnectionInfo As Item)

If ConnectionInfo Is Nothing Then Exit Sub

If m_Count > 0 Then

If Not Me.ConnectionInfo(ConnectionInfo.ID) Is Nothing Then

MsgBox(ID.ToString & "已存在")

Exit Sub

End If

End If

ReDim Preserve Me.Items(m_Count)

Me.Items(m_Count) = ConnectionInfo

m_Count += 1

End Sub

'取指定ID的配置信息

Public ReadOnly Property ConnectionInfo(ByVal ID As Integer) As Item

Get

Dim mItem As Item

Dim i As Integer

For i = 0 To m_Count - 1

If Me.Items(i).ID = ID Then

mItem = Me.Items(ID)

Exit For

End If

Next

Return mItem

End Get

End Property

'序列化并保存到指定文件

Public Sub SaveXmlFile(ByVal FileName As String)

If Me Is Nothing Then Exit Sub

Dim XmlWriter As New System.IO.StreamWriter(FileName, False)

XmlWriter.Write(SerializeClass.GetXML(Me))

XmlWriter.Close()

End Sub

'从指定文件读取反序列化转为对象

Public Function LoadXmlFile(ByVal FileName As String) As Config

Dim XmlReader As New System.IO.StreamReader(FileName, System.Text.Encoding.Default)

Dim mConfig As Config

mConfig = CType(SerializeClass.LoadXML(GetType(Config), XmlReader.ReadToEnd), Config)

XmlReader.Close()

mConfig.m_Count = mConfig.Items.Length

Return mConfig

End Function

End Class


就以上两步就可以了，下面这个类是用来序列化用的。

'这是用XmlSerializer序列化对象的类

Public Class SerializeClass

Public Shared Function GetXML(ByVal mObject As Object) As String

Dim oSerializer As New System.Xml.Serialization.XmlSerializer(mObject.GetType)

Dim oStringWriter As New System.IO.StringWriter

oSerializer.Serialize(oStringWriter, mObject)

Return oStringWriter.ToString

End Function

Public Shared Function LoadXML(ByVal mClass As Type, ByVal XML As String) As Object

Dim oSerializer As New System.Xml.Serialization.XmlSerializer(mClass)

Dim oStringReader As New System.IO.StringReader(XML)

Return oSerializer.Deserialize(oStringReader)

End Function

End Class


以下是使用方法示例：

'测试存配置文件

Private Sub TestSaveConfig()

Dim mConfig As Config = New Config

Dim mItem As Item

mItem = New Item

mConfig.Add(mItem)

mItem = New Item

With mItem

.ID = 1

.User = "Master"

.Password = "123456"

.Tusted = False

End With

mConfig.Add(mItem)

mConfig.SaveXmlFile(Application.StartupPath & "\Config.xml")

End Sub

'测试读配置文件

Private Sub TestLoadConfig()

Dim mConfig As Config = New Config

mConfig = mConfig.LoadXmlFile(Application.StartupPath & "\Config.xml")

'读取默认值的用户名

MsgBox(mConfig.Items(mConfig.ID).User)

'不妨修改一下配置

mConfig.ID = 1

mConfig.ConnectionInfo(0).Server = "Server"

mConfig.ConnectionInfo(1).Database = "Master"

'再存盘

mConfig.SaveXmlFile(Application.StartupPath & "\Config.xml")

End Sub