XML序列化在VB.Net中产生内存不足错误

我将尽力提供尽可能多的必要细节。在投票否决我之前，请询问更多细节。 我们正在尝试序列化一个对象，该对象内部有一个名为ObjList的CollectionBase属性。下面所涉及的课程示例

调用Serialize函数时，我们使用XmlTextWriter序列化对象，然后在写入程序填充的MemoryStream上使用StreamReader.ReadToEnd读入字符串对象。 在尝试从内存流读取时，我们会出现“内存不足”错误

MemoryStream.Length显示略多于2亿字节。正在序列化的对象在其ObjList属性类型CollectionBase中有17922个对象，每个对象都有一个ObjList，其中包含可变数量的数据

以下是序列化代码：

Public Class XMLserializer(Of T)

    Public _serializer As New System.Xml.Serialization.XmlSerializer(GetType(T))

    '... Some other code  

    Public Function Serialize(ByVal myobject As T) As String
        'Reset local varaible to actual object type         
        _serializer = New System.Xml.Serialization.XmlSerializer(myobject.GetType)
        'serialise to a memory stream, then read into a string  
        Try
            Dim result As String = Nothing
            If myobject IsNot Nothing Then
                Using ms As New MemoryStream
                    Using xtw As New XmlTextWriter(ms, System.Text.Encoding.UTF8)
                        xtw.Formatting = Formatting.Indented
                        _serializer.Serialize(xtw, myobject)
                        'rewind  
                        ms.Seek(0, System.IO.SeekOrigin.Begin)
                        Using reader As New StreamReader(ms, Text.Encoding.UTF8)
                            result = reader.ReadToEnd()
                            xtw.Close()
                            reader.Close()
                        End Using
                    End Using
                End Using
            End If

            Return result

        Catch ex As Exception
            Throw
        End Try
    End Function

末级

以下是我的对象定义：

<Serializable()> _
Public Class SLMR_ObjList(Of T)
    Inherits Collections.CollectionBase
    Implements IList(Of T)

    '.... Properties and Methods

End Class

' Location objects
<Serializable()> _
Public Class LocationCollection

    Private _serializer As XMLserializer(Of LocationCollection) = Nothing

    Private _locationList As SLMR_ObjList(Of Location)
    Public Property LocationList As SLMR_ObjList(Of Location)
        Get 
            If _locationList Is Nothing Then
                _locationList = New SLMR_ObjList(Of Location)
            End If
            Return _locationList
        End Get
        Set(ByVal value As SLMR_ObjList(Of Location))
            _locationList = value
        End Set
    End Property

    Public Sub Search_EquipNotInspected() 'As String
        Dim ds As DataSet = Nothing
        Dim dt As DataTable = Nothing
        Try
            Me.ObjList.Clear()
            ds = DAO_AS400_ELVPLOC00.SearchForEquipNotInspected(_search_counties,
                                                     _search_fromdate,
                                                     _search_todate)
            dt = ds.Tables(0)
            If dt.Rows.Count > 0 Then
                For Each dr As DataRow In dt.Rows
                    Dim curLocation As AS400_ELVPLOC00
                    ' Check and load the current location, or create new entry  
                    curLocation = Me.ObjList.FindByProperty("ID", dr.Item("LocID"))
                    If IsNothing(curLocation) OrElse curLocation.ID = 0 Then 
                        curLocation = New AS400_ELVPLOC00
                        With curLocation
                            .ID = dr.Item("LocID")
                            .Address1 = dr.Item("Addr1")
                            ' ...  
                        End With
                        Me.ObjList.Add(curLocation)
                    End If

                    Dim curEquipment As New AS400_ELVPEQP00
                    With curEquipment
                        .ID = dr.Item("EquipID")
                        .ELBLDGCD = dr.Item("ELBLDGCD")
                        ' ...  
                    End With
                    curLocation.AS400_ELVPEQP_COL.ObjList.Add(curEquipment)
                Next
            End If
        Catch ex As Exception
            'TO DO:  Handle Exception  
        Finally
            If Not ds Is Nothing Then
                ds.Dispose()
            End If
        End Try
    End Sub

    Public Function XMLDATA() As String
        Return XMLSerialize(Me)
    End Function

    Public Shared Function XMLSerialize(ByVal myobject As LocationCollection) As String
        If _serializer Is Nothing Then
            _serializer = New XMLserializer(Of LocationCollection)
        End If
        Return _serializer.Serialize(myobject)
    End Function

End Class

<Serializable()> _
Public Class Location
    Private _id As Integer
    Public Property ID As Integer
        Get 
            Return _id 
        End Get
        Set(ByVal value As Integer
            _id = value
        End Set
    End Property

    Private _address1 As String
    Public Property Address1 As String
        Get 
            Return _address1 
        End Get
        Set(ByVal value As String
            _address1 = value
        End Set
    End Property

    '.... other values

    Private _equipCollection As EquipmentCollection
    Public Property EquipCol As EquipmentCollection
        Get 
            If _equipCollection Is Nothing Then
                _equipCollection = New EquipmentCollection
            End If
            Return _equipCollection 
        End Get
        Set(ByVal value As EquipmentCollection)
            _equipCollection = value
        End Set
    End Property
End Class

' Equipment objects  
<Serializable()> _
Public Class EquipmentCollection
    Private _equipmentList As SLMR_ObjList(Of Equipment)
    Public Property EquipmentList As SLMR_ObjList(Of Equipment)
        Get 
            If _equipmentList Is Nothing Then
                _equipmentList = New SLMR_ObjList(Of Equipment)
            End If
            Return _equipmentList 
        End Get
        Set(ByVal value As SLMR_ObjList(Of Equipment))
            _equipmentList = value
        End Set
    End Property
End Class

<Serializable()> _
Public Class Equipment
    Private _id As Integer
    Public Property ID As Integer
        Get 
            Return _id 
        End Get
        Set(ByVal value As Integer
            _id = value
        End Set
    End Property

    Private _equipManuf As String
    Public Property Manufacturer As String
        Get 
            Return _equipManuf 
        End Get
        Set(ByVal value As String
            _equipManuf = value
        End Set
    End Property

    Private _equipLocation As Location
    Public Property EquipLocation As Location
        Get 
            If _equipLocation Is Nothing Then
                _equipLocation = New Location
            End If
            Return _equipLocation 
        End Get
        Set(ByVal value As Location
            _equipLocation = value
        End Set
    End Property

End Class

---

有了34000条记录，我们就会出现内存不足的错误。如果我们使用<2000条记录，它就可以工作。有没有想过如何找出我们为什么会出错？

Try/Catch-Throw-End-Catch-End-Try什么都不做。仅供参考，您不应该使用新的XmlTextReader或XmlTextWriter。自.NET 2.0以来，它们一直被弃用。请改用XmlReader.Create或XmlWriter.Create。谢谢。我正在使用XmlWriter.Create。此外，Try/Catch为我在调试期间捕获线程提供了一个位置。有没有更有效的方法来实现这一点？在我测试时，我获取了主对象，并遍历了集合，对每个对象进行了XML序列化。正如我所做的，ad将它们附加到StringBuilder对象。StringBuilder长度=183324697，当我尝试执行StringBuilder.ToString时，我得到System.OutOfMemoryException，因此它一定是太多数据了。但是为什么呢？我们使用的是32位系统。。。我想我可以拿到2147483647，或者至少1073741823。我在这里实际使用的限制是什么？我认为可以将调试器设置为在特定类型的未处理异常上中断。在任何情况下，如果你只是在评论说，这是调试的目的，这将使我高兴。

Dim locCollection As New LocationCollection
'.... set object's search properties  
locCollection.Search_EquipNotinspected() ' Gets 34002 records, which works out to 17922 Location objects  
Dim xml As String = locCollection.XMLDATA