Question

此代码导致错误

的System.OutOfMemoryException

Using VT As New BidiEntities  
    For Each dr In Bidis

        Dim hkBidi As New hkBidi
        hkBidi.UserId = Userx
        VT.AddTohkBidis(hkBidi)
    Next    
   *VT.SaveChanges()*    
End Using

循环遍历500,000条记录时，

VT.SaveChanges()会导致此错误。

如何解决这个问题？

Answer 1

如果你试图存储500,000条记录，并且这样做会出现内存不足异常，那么你需要重构你的循环以执行每x条记录的SaveChanges，其中x是一些不会导致异常的值（即10,000）。

这将使您的代码稍微复杂一些，但性能更高：

Dim wCount As Integer
Const MAX_LOOPS As Integer = 10000
Dim VT As BidiEntities

Try
    For Each dr In Bidis
        If VT Is Nothing Then 
           wCount = 0
           VT = New BidiEntities
        End If

        Dim hkBidiAs New hkBidi
        hkBidi.UserId = Userx
        VT.AddTohkBidis(hkBidi)

        wCount = wCount + 1
        ' When we reach the maximum number of loops, save the changes, then dispose the VT Object and set it to nothing
        If wCount >= MAX_LOOPS Then
            VT.SaveChanges()
            VT.Dispose()
            VT = Nothing
        End If
    Next
Catch
   ' Do something with the exception
Finally
    ' Handle the records added in the last loop, if any
    If VT IsNot Nothing Then
        VT.SaveChanges()
        VT.Dispose()
        VT = Nothing
    End If
End Try

Answer 2

我认为这种方法。 competent_tech和p.campbell谢谢！：）

        Dim i As Integer
        Dim uList As New List(Of hkBidi)

        For Each dr In Bidis
            i += 1

            uList.Add(New hkBidi With {.UserId = dr.UserId})

            If i > 9999 Then
                i = 0
                BidiSave(uList)
                uList.Clear()
            End If
        Next
' Up to 500000 if the (sample 502500) and smaller than 10000
        If uList.Any() Then
            BidiSave(uList)
        End If

-

Public Sub BidiSave(uList As List(Of hkBidi))
    Using VT As New BidiEntities
        For Each dr In uList
            VT.AddTohkBidis(dr)
        Next
        VT.SaveChanges() ' No Problem
    End Using ' No Exception
End Sub

循环500K记录后OutOfMemoryException

2 个答案: