跳过字节数组

Question

在 VB .Net 中，正在构建一个类对象来读取二进制数据库文件并处理记录。

首先我获取二进制文件的全部内容，然后使用 .Skip().Take() 方法对其进行处理。不幸的是，这些方法会降低应用程序的速度。

我的问题是：有没有比使用 .Skip().Take() 方法更快的方法来处理数据？

下面是一些示例代码：

Public Sub ExampleCode(ByVal filename As String)
    Dim length As Long
    Dim content As Byte()
    Dim records As New List(Of Array)

    'Following constants are in actuality extracted from a header...
    Const _NumberOfRecords = 2000000
    Const _NumberOf Fields = 48

    'Get the contant for specified file
    content = My.Computer.FileSystem.ReadAllBytes(filename)

    'Process all fields for this record
    For j As Long = 0 To _NumberOfRecords - 1

        Dim record(_NumberOfFields - 1)
        lastPos = 1320
        For i As Long = 0 To _NumberOfFields - 1
            'Get the field length from_FieldDescriptors that is 
            'normally extracted from a fields section in the binary file
            length = _FieldDescriptors(i).Length

            'Get the value and add it to this record
            record(i) = _Content.Skip(lastPos).Take(length).ToArray

            'Proceed to the next field
            lastPos += length
        Next i
        _Records.Add(record)
    Next j
End Sub

Answer 1

如果_Content是Array，你可以试试Array.Copy，应该会更快：

record(i) = New Byte(length) {}

Array.Copy(_Content, lastPos, record(i), 0, length);