壓縮正在工作，但解壓縮不是

Question

我在寫一些代碼來將字節數組壓縮成一個較小的字節數組。然後我想解壓：

''' <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 

（我採納了這個here代碼）

我的壓縮編碼的作品，但我的解壓縮代碼提供了以下錯誤：

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

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

我已經嘗試了許多變化gzip.Read和交換變量。 （如果我知道如何窺視VB.NET內源代碼，就像我可以跟JDK也許我可以逆向工程我的方法，以解決方案，很好哦）

我怎樣才能重新裝備我DeCompress功能工作意？

編輯： 我注意到我落選投票因爲我沒有顯示.Read方法的使用。那麼我不能跟隨.Read算法，因爲我的VB.NET沒有.CopyTo()函數。我不明白爲什麼：

直接從MSDN採取

Answer 1

當您解壓時，您正在嘗試寫入解壓縮流。現在它是如何工作的 - 當解壓縮時，它在讀取解壓縮流時從流中讀取數據。

快速的解決方法如下所示：

''' <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 

請注意，我現在有「記憶」，從「壓縮」字節排列讀，並將其複製到一個新的輸出流。

編輯：增加了對Stream.CopyTo()的替代品，因爲提問者必須打擊.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，而你試圖寫它的例子從decompresser流如何讀取