我试图创建一个实现IXmlSerializable的通用字典(信用到
Charles Feduke).
这是我的试用版:
Sub Main()
Dim z As New SerializableDictionary(Of String, String)
z.Add("asdf", "asd")
Console.WriteLine(z.Serialize)
End Sub
结果:
<?xml version="1.0" encoding="utf-16"?><Entry key="asdf" value="asd" />
我在WriteXml方法的顶部放置了一个断点,我看到当它停止时,编写器根本不包含数据,而恕我直言,它应该包含根元素和xml声明.
<Serializable()> _
Public Class SerializableDictionary(Of TKey, TValue) : Inherits Dictionary(Of TKey, TValue) : Implements IXmlSerializable
Private Const EntryString As String = "Entry"
Private Const KeyString As String = "key"
Private Const ValueString As String = "value"
Private Shared ReadOnly AttributableTypes As Type() = New Type() {GetType(Boolean), GetType(Byte), GetType(Char), GetType(DateTime), GetType(Decimal), GetType(Double), GetType([Enum]), GetType(Guid), GetType(Int16), GetType(Int32), GetType(Int64), GetType(SByte), GetType(Single), GetType(String), GetType(TimeSpan), GetType(UInt16), GetType(UInt32), GetType(UInt64)}
Private Shared ReadOnly GetIsAttributable As Predicate(Of Type) = Function(t) AttributableTypes.Contains(t)
Private Shared ReadOnly IsKeyAttributable As Boolean = GetIsAttributable(GetType(TKey))
Private Shared ReadOnly IsValueAttributable As Boolean = GetIsAttributable(GetType(TValue))
Private Shared ReadOnly GetElementName As Func(Of Boolean, String) = Function(isKey) If(isKey, KeyString, ValueString)
Public Function GetSchema() As System.Xml.Schema.XmlSchema Implements System.Xml.Serialization.IXmlSerializable.GetSchema
Return Nothing
End Function
Public Sub WriteXml(ByVal writer As XmlWriter) Implements IXmlSerializable.WriteXml
For Each entry In Me
writer.WriteStartElement(EntryString)
WriteData(IsKeyAttributable, writer, True, entry.Key)
WriteData(IsValueAttributable, writer, False, entry.Value)
writer.WriteEndElement()
Next
End Sub
Private Sub WriteData(Of T)(ByVal attributable As Boolean, ByVal writer As XmlWriter, ByVal isKey As Boolean, ByVal value As T)
Dim name = GetElementName(isKey)
If attributable Then
writer.WriteAttributeString(name, value.ToString)
Else
Dim serializer As New XmlSerializer(GetType(T))
writer.WriteStartElement(name)
serializer.Serialize(writer, value)
writer.WriteEndElement()
End If
End Sub
Public Sub ReadXml(ByVal reader As XmlReader) Implements IXmlSerializable.ReadXml
Dim empty = reader.IsEmptyElement
reader.Read()
If empty Then Exit Sub
Clear()
While reader.NodeType <> XmlNodeType.EndElement
While reader.NodeType = XmlNodeType.Whitespace
reader.Read()
Dim key = ReadData(Of TKey)(IsKeyAttributable, reader, True)
Dim value = ReadData(Of TValue)(IsValueAttributable, reader, False)
Add(key, value)
If Not IsKeyAttributable AndAlso Not IsValueAttributable Then reader.ReadEndElement() Else reader.Read()
While reader.NodeType = XmlNodeType.Whitespace
reader.Read()
End While
End While
reader.ReadEndElement()
End While
End Sub
Private Function ReadData(Of T)(ByVal attributable As Boolean, ByVal reader As XmlReader, ByVal isKey As Boolean) As T
Dim name = GetElementName(isKey)
Dim type = GetType(T)
If attributable Then
Return Convert.ChangeType(reader.GetAttribute(name), type)
Else
Dim serializer As New XmlSerializer(type)
While reader.Name <> name
reader.Read()
End While
reader.ReadStartElement(name)
Dim value = serializer.Deserialize(reader)
reader.ReadEndElement()
Return value
End If
End Function
Public Shared Function Serialize(ByVal dictionary As SerializableDictionary(Of TKey, TValue)) As String
Dim sb As New StringBuilder(1024)
Dim sw As New StringWriter(sb)
Dim xs As New XmlSerializer(GetType(SerializableDictionary(Of TKey, TValue)))
xs.Serialize(sw, dictionary)
sw.Dispose()
Return sb.ToString
End Function
Public Shared Function Deserialize(ByVal xml As String) As SerializableDictionary(Of TKey, TValue)
Dim xs As New XmlSerializer(GetType(SerializableDictionary(Of TKey, TValue)))
Dim xr As New XmlTextReader(xml, XmlNodeType.Document, Nothing)
xr.Close()
Return xs.Deserialize(xr)
End Function
Public Function Serialize() As String
Dim sb As New StringBuilder
Dim xw = XmlWriter.Create(sb)
WriteXml(xw)
xw.Close()
Return sb.ToString
End Function
Public Sub Parse(ByVal xml As String)
Dim xr As New XmlTextReader(xml, XmlNodeType.Document, Nothing)
ReadXml(xr)
xr.Close()
End Sub
End Class
最佳答案 它为什么包含根?你没有在Serialize中添加一个,你创建XmlWriter …我想知道你是否应该有更多的东西(C#,对不起):
public string Serialize() {
StringBuilder sb = new StringBuilder();
XmlSerializer ser = new XmlSerializer(
typeof(SerializableDictionary<TKey, TValue>));
using (XmlWriter writer = XmlWriter.Create(sb)) {
ser.Serialize(writer, this);
}
return sb.ToString();
}
这使用常规的XmlSerializer核心来编写外部元素.或者,将Serialize更改为包含您选择的外部元素.