INI的替代品--XML配置文件读取与保存
.Net中并没有提供INI读写的托管类库，如果使用INI必须调用非托管API。有一个NINI提供了托管类库。
今天我们来实现XML配置文件读取与保存。
1.集合类
首先我们需要一个集合类来保存键和键值。它必须同时提供键名和索引两种查找键值的办法。所以我们采用 System.Collections.Specialized.NameValueCollection 类。需要注意的是这个类的键值只能是String。
Imports System.Xml
Public Class Setting
Inherits System.Collections.Specialized.NameValueCollection
End Class
2.XML配置文件格式
配置文件格式我们采用app.config的格式
<?xml version="1.0" encoding="utf-8"?>
<configuration>
<appSettings>
<add key="key1" value="value1"/>
</appSettings>
</configuration>
3.XML配置文件的读取
Sub LoadSetting(ByVal FilePath As String)
Dim Reader As XmlTextReader
Try
Reader = New XmlTextReader(FilePath)
Reader.WhitespaceHandling = WhitespaceHandling.None '忽略所用Whitespace
Me.Clear() '清除现有所有数据
Catch ex As Exception
MsgBox("找不到XML文件" + ex.ToString)
Exit Sub
End Try
Try
While Reader.Read
If Reader.Name = "add" Then
Dim Key, Value As String
Reader.MoveToAttribute("key")
Key = Reader.Value
Reader.MoveToAttribute("value")
Value = Reader.Value
Me.Set(Key, Value)
Reader.MoveToElement()
End If
End While
Catch ex As Exception
MsgBox("XML文件格式错误" + ex.ToString)
Exit Sub
Finally
Reader.Close()
End Try
End Sub
3.XML配置文件的写入
Sub SaveSetting(ByVal FilePath As String)
Dim Writer As New XmlTextWriter(FilePath, System.Text.Encoding.Default)
Writer.WriteStartDocument() '写入XML头
Dim I As Integer
Writer.WriteStartElement("configuration")
Writer.WriteStartElement("appSettings")
For I = 0 To Me.Count - 1
Writer.WriteStartElement("add")
Writer.WriteStartAttribute("key", String.Empty)
Writer.WriteRaw(Me.GetKey(I))
Writer.WriteEndAttribute()
Writer.WriteStartAttribute("value", String.Empty)
Writer.WriteRaw(Me.Item(I))
Writer.WriteEndAttribute()
Writer.WriteEndElement()
Next
Writer.WriteEndElement()
Writer.WriteEndElement()
Writer.Flush()
Writer.Close()
End Sub
