多线程写文件

Question

如何多线程调用下面的方法不产生冲突
  Private Sub WriteEmailTxt(ByVal email As String)

     
        Dim fs As New FileStream(Application.StartupPath & "\email.txt", FileMode.OpenOrCreate, FileAccess.Write)
        Dim m_streamWriter As New StreamWriter(fs)
        m_streamWriter.BaseStream.Seek(0, SeekOrigin.[End])
        m_streamWriter.WriteLine(email)
        m_streamWriter.Flush()
        m_streamWriter.Close()
        fs.Close()

    End Sub

Answer 1

Private syncRoot As Object = New [Object]()
Private Sub WriteEmailTxt(ByVal email As String)
    SyncLock syncRoot
        Dim fs As New FileStream(Application.StartupPath & "\email.txt", FileMode.OpenOrCreate, FileAccess.Write)
        Dim m_streamWriter As New StreamWriter(fs)
        m_streamWriter.BaseStream.Seek(0, SeekOrigin.[End])
        m_streamWriter.WriteLine(email)
        m_streamWriter.Flush()
        m_streamWriter.Close()
       
        fs.Close()
    End SyncLock
End Sub

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知识改变命运，奋斗成就人生!

Answer 2

你好 可以添加个lock

Private Shared ReadOnly Property InternalSyncObject As Object
    Get
        If (s_InternalSyncObject Is Nothing) Then
            Dim obj2 As New Object
            Interlocked.CompareExchange((s_InternalSyncObject), obj2, Nothing)
        End If
        Return s_InternalSyncObject
    End Get
End Property

Dim s_InternalSyncObject As Object

Private Sub WriteEmailTxt(ByVal email As String)

      SyncLock InternalSyncObject
        Dim fs As New FileStream(Application.StartupPath & "\email.txt", FileMode.OpenOrCreate, FileAccess.Write)
        Dim m_streamWriter As New StreamWriter(fs)
        m_streamWriter.BaseStream.Seek(0, SeekOrigin.[End])
        m_streamWriter.WriteLine(email)
        m_streamWriter.Flush()
        m_streamWriter.Close()
        fs.Close()

End SyncLock
    End Sub

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Wenn ich dich hab’,gibt es nichts, was unerträglich ist.坚持不懈！http://hi.baidu.com/1987raymond

Answer 3

版主的代码好像有点问题吧，

Answer 4

版主的代码不能解决问题啊，仍然显示错误，正在被另一进程使用？

Answer 5

你好！

出现这种情况的原因是因为你在另外的代码里对 email.txt 进行了读写，并且没有加锁

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知识改变命运，奋斗成就人生!

Answer 6

版主的代码不能解决问题啊，仍然显示错误，正在被另一进程使用？

你好！
     如果是“正在被另一进程使用”，那不是线程的问题，而是进程的问题！
     说明有其他程序正在使用这个资源，你检查一下！

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周雪峰