在 ASP.NET 中读取分块传输编码的 http 请求的正文

public static byte[] ReadChunkedRequestBody(HttpListenerRequest request)
{
    var inputStream = request.InputStream;
    var buffer = new MemoryStream();

    // 读取分块数据
    while (true)
    {
        // 读取分块长度
        var chunkSizeLine = ReadLine(inputStream);
        if (string.IsNullOrEmpty(chunkSizeLine))
        {
            break;
        }

        // 将分块长度转换为十六进制数值
        var chunkSize = int.Parse(chunkSizeLine, NumberStyles.HexNumber);

        // 读取分块数据
        var chunkData = new byte[chunkSize];
        var bytesRead = 0;
        while (bytesRead< chunkSize)
        {
            var read = inputStream.Read(chunkData, bytesRead, chunkSize - bytesRead);
            if (read == 0)
            {
                break;
            }

            bytesRead += read;
        }

        // 将分块数据写入缓冲区
        buffer.Write(chunkData, 0, bytesRead);

        // 读取分块结束符
        var endOfChunk = ReadLine(inputStream);
        if (endOfChunk != "")
        {
            throw new Exception("Invalid chunked encoding");
        }

        // 如果分块长度为 0，则表示数据已经读取完毕
        if (chunkSize == 0)
        {
            break;
        }
    }

    return buffer.ToArray();
}

private static string ReadLine(Stream stream)
{
    var buffer = new byte[1];
    var line = new StringBuilder();

    while (true)
    {
        var read = stream.Read(buffer, 0, 1);
        if (read == 0)
        {
            break;
        }

        if (buffer[0] == '\n')
        {
            break;
        }

        line.Append((char)buffer[0]);
    }

    return line.ToString();
}