Question

我正在使用下面的代码尝试打开pdf文件而我收到的错误无法打开已关闭的文件？不知道我在这里缺少什么。

    Dim FileName As String
    Dim FolderLocation As String = Nothing
    Dim FileFormat As String = "application/pdf"
    Dim tFileNameArray As Array = Nothing
    Dim tFileName As String = Nothing

    FileName = "\\Server\Files\45144584.pdf"

    Dim fs As New FileStream(FileName, FileMode.Open, FileAccess.Read)
    Using (fs)

    End Using
    Dim data() As Byte = New Byte(fs.Length) {}
    Dim br As BinaryReader = New BinaryReader(fs)
    br.Read(data, 0, data.Length)
    br.Close()
    Response.Clear()
    Response.ContentType = FileFormat
    Response.AppendHeader("Content-Disposition", "attachment; filename=" & tFileName.Split("\")(tFileName.Split("\").Length - 1))
    Response.BufferOutput = True
    Response.BinaryWrite(data)
    Response.End()

Answer 1

您需要在使用中包含引用fs的所有代码，否则您将尝试访问已经处置的对象。我也会对BinaryReader做同样的事情，因为它也实现了IDisposable：

Dim data() As Byte
Using fs As New FileStream(FileName, FileMode.Open, FileAccess.Read)
    data = New Byte(fs.Length) {}
    Using br As New BinaryReader(fs)
        br.Read(data, 0, data.Length)
    End Using
End Using
...

Answer 2

您有以下几行：

Using (fs)

End Using

结束使用后，文件关闭，fs对象被处理掉。

您需要将使用fs读取的代码放在using块中。

Answer 3

Dim fs As New FileStream(FileName, FileMode.Open, FileAccess.Read)
Using (fs)

End Using
Dim data() As Byte = New Byte(fs.Length) {}
...

您在处置后尝试使用fs。这需要：

Dim fs As New FileStream(FileName, FileMode.Open, FileAccess.Read)
Using (fs)
    Dim data() As Byte = New Byte(fs.Length) {}
    Dim br As BinaryReader = New BinaryReader(fs)
    br.Read(data, 0, data.Length)
    br.Close() 
End Using

无法打开已关闭的文件

3 个答案: