如何在 C# 中解压缩 GZip 压缩字符串？

Question

目前一直在尝试解压缩 GZip 压缩的字符串，我正在使用此功能：

private static string Decompress(byte[] bytes)
{
    using (var memoryStream = new MemoryStream(bytes))
    using (var gZipStream = new GZipStream(memoryStream, CompressionMode.Decompress))
    using (var memoryStreamOutput = new MemoryStream()) 
    {
        gZipStream.CopyTo(memoryStreamOutput);
        var outputBytes = memoryStreamOutput.ToArray();

        string decompressed = Encoding.UTF8.GetString(outputBytes);
        return decompressed;
    }
}

而且每当我运行代码时，我在调用函数时插入的字符串在应该解压缩的地方都没有改变。我也尝试过使用 StreamReader，但也没有用。发生了什么？

Answer 1

如果我们首先对它的压缩方式做出合理的假设，那么显示的代码就可以正常工作：

using System;
using System.IO;
using System.IO.Compression;
using System.Text;

static class P
{
    static void Main()
    {
        Console.WriteLine(lipsum.Length); // 61125 chars of lipsum (not shown)
        Console.WriteLine(Encoding.UTF8.GetByteCount(lipsum)); // 61125 bytes of lipsum
        var bytes = Compress(lipsum);
        Console.WriteLine(bytes.Length); // 16795 bytes compressed
        var value = Decompress(bytes);
        Console.WriteLine(value.Length); // 61125 bytes again when decompressed
        Console.WriteLine(value == lipsum); // True - it worked fine
    }
    private static byte[] Compress(string value)
    {
        using (var memoryStream = new MemoryStream())
        {
            using (var gZipStream = new GZipStream(memoryStream, CompressionMode.Compress))
            {
                gZipStream.Write(Encoding.UTF8.GetBytes(value));
            }
            return memoryStream.ToArray();
        }
    }
    private static string Decompress(byte[] bytes)
    {
        using (var memoryStream = new MemoryStream(bytes))
        using (var gZipStream = new GZipStream(memoryStream, CompressionMode.Decompress))
        using (var memoryStreamOutput = new MemoryStream())
        {
            gZipStream.CopyTo(memoryStreamOutput);
            var outputBytes = memoryStreamOutput.ToArray();

            string decompressed = Encoding.UTF8.GetString(outputBytes);
            return decompressed;
        }
    }

    // MASSIVELY TRUNCATED FOR POST!
    const string lipsum = @"Lorem ipsum dolor sit amet,  ... ac dolor ac hendrerit.";
}