c#-4.0 - 编写要在 Web API MessageHandler 中使用的解压缩机制

Question

我正在尝试为 Web API MessageHandler 编写一个解压缩机制。然而，尽管进行了一些研究，我似乎无法完成这项工作:-(

通过以下测试可以重现该问题:

[Test]
public void Deflate()
{
    using (var outStream = new MemoryStream())
    {
        using (var compressionStream = new DeflateStream(outStream, CompressionMode.Compress, true))
        {
            using (var original = new MemoryStream(Encoding.UTF8.GetBytes("original content")))
            {
                original.CopyTo(compressionStream);
            }
        }
        //this passes
        Assert.IsTrue(outStream.Length > 0);

        var compressedStream = outStream;
        var decompressionResultStream = compressedStream.DeflateDecompressor();

        //this fails
        Assert.IsTrue(decompressionResultStream.Length > 0);

        var output = Encoding.UTF8.GetString(decompressionResultStream.ToArray());
        Assert.AreEqual("original content", output);
    }
}

以及以下解压缩处理程序

public static class DecompressionHandlers
{
    public static MemoryStream DeflateDecompressor(this Stream compressedStream)
    {
        var decompressionResultStream = new MemoryStream();
        using (var decompressionStream = new DeflateStream(compressedStream, CompressionMode.Decompress, true))
        {
            decompressionStream.CopyTo(decompressionResultStream);
            decompressionStream.Flush();
        }
        return decompressionResultStream;
    }

    public static MemoryStream GZipDecompressor(this Stream compressedStream)
    {
        var decompressionResultStream = new MemoryStream();
        using (var decompressionStream = new GzipStream(compressedStream, CompressionMode.Decompress, true))
        {
            decompressionStream.CopyTo(decompressionResultStream);
            decompressionStream.Flush();
        }
        return decompressionResultStream;
    }
}

希望这是一个直接的 ID-10-T 问题，非常感谢您提供任何建议!

这将在 Web API MessageHandler 中使用，这很可能是转移注意力，但为了完整性而包含在内

Answer 1

在您的代码中，在调用解压缩之前尝试重置 compressedStream 的位置。

compressedStream.Position = 0;
var decompressionResultStream = compressedStream.DeflateDecompressor();

请注意，您似乎在 GZipDecompressor 方法中使用 DeflateStream 而不是 GZipStream。