压缩正在工作，但解压缩不是

Question

我在写一些代码来将字节数组压缩成一个较小的字节数组。然后我想解压：

''' <summary> 
''' Receives bytes, returns compressed bytes. 
''' </summary> 
Function Compress(ByRef raw() As Byte) As Byte() 
    Using memory As MemoryStream = New MemoryStream() 
     Using gzip As GZipStream = New GZipStream(memory, CompressionMode.Compress) 
      gzip.Write(raw, 0, raw.Length) 
     End Using 
     Return memory.ToArray() 
    End Using 
End Function 

''' <summary> 
''' Receives compressed bytes, returns bytes. 
''' </summary> 
Function DeCompress(ByRef compress() As Byte) As Byte() 
    Using memory As MemoryStream = New MemoryStream() 
     Using gzip As GZipStream = New GZipStream(memory, CompressionMode.Decompress) 
      gzip.Write(compress, 0, compress.Length) 
     End Using 
     Return memory.ToArray() 
    End Using 
End Function 

（我采纳了这个here代码）

我的压缩编码的作品，但我的解压缩代码提供了以下错误：

An unhandled exception of type 'System.InvalidOperationException' occurred in System.dll

Additional information: Writing to the compression stream is not supported.

我已经尝试了许多变化gzip.Read和交换变量。 （如果我知道如何窥视VB.NET内源代码，就像我可以跟JDK也许我可以逆向工程我的方法，以解决方案，很好哦）

我怎样才能重新装备我DeCompress功能工作意？

编辑： 我注意到我落选投票因为我没有显示.Read方法的使用。那么我不能跟随.Read算法，因为我的VB.NET没有.CopyTo()函数。我不明白为什么：

直接从MSDN采取

Answer 1

当您解压时，您正在尝试写入解压缩流。现在它是如何工作的 - 当解压缩时，它在读取解压缩流时从流中读取数据。

快速的解决方法如下所示：

''' <summary> 
''' Receives bytes, returns compressed bytes. 
''' </summary> 
Function Compress(ByRef raw() As Byte) As Byte() 
    Using memory As MemoryStream = New MemoryStream() 
     Using gzip As GZipStream = New GZipStream(memory, CompressionMode.Compress) 
      gzip.Write(raw, 0, raw.Length) 
     End Using 
     Return memory.ToArray() 
    End Using 
End Function 

''' <summary> 
''' Receives compressed bytes, returns bytes. 
''' </summary> 
Function DeCompress(ByRef compress() As Byte) As Byte() 
    Using output As MemoryStream = New MemoryStream() 
     Using memory As MemoryStream = New MemoryStream(compress) 
      Using gzip As GZipStream = New System.IO.Compression.GZipStream(memory, CompressionMode.Decompress) 
       CopyStreamToStream(gzip,output) 
      End Using 
      Return output.ToArray() 
     End Using 
    End Using 
End Function 


Public Shared Sub CopyStreamToStream(input As Stream, output As Stream) 
    Dim buffer As Byte() = New Byte(16 * 1024 - 1) {} 
    ' Fairly arbitrary size 
    Dim bytesRead As Integer 

    While (InlineAssignHelper(bytesRead, input.Read(buffer, 0, buffer.Length))) > 0 
     output.Write(buffer, 0, bytesRead) 
    End While 
End Sub 
Private Shared Function InlineAssignHelper(Of T)(ByRef target As T, ByVal value As T) As T 
    target = value 
    Return value 
End Function 

请注意，我现在有“记忆”，从“压缩”字节排列读，并将其复制到一个新的输出流。

编辑：增加了对Stream.CopyTo()的替代品，因为提问者必须打击.NET 3.5

Answer 2

例如在the GZipStream Class：

Private Sub Decompress(ByVal fileToDecompress As FileInfo) 
    Using originalFileStream As FileStream = fileToDecompress.OpenRead() 
     Dim currentFileName As String = fileToDecompress.FullName 
     Dim newFileName = currentFileName.Remove(currentFileName.Length - fileToDecompress.Extension.Length) 

     Using decompressedFileStream As FileStream = File.Create(newFileName) 
      Using decompressionStream As GZipStream = New GZipStream(originalFileStream, CompressionMode.Decompress) 
       decompressionStream.CopyTo(decompressedFileStream) 
       Console.WriteLine("Decompressed: {0}", fileToDecompress.Name) 
      End Using 
     End Using 
    End Using 
End Sub 

看，而你试图写它的例子从decompresser流如何读取