如何压缩HttpWebRequest POST

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

public class HttpCompressionExample
{
    public static void Main(string[] args)
    {
        string url = "http://example.com/api";
        string postData = "Hello, World!";

        // 创建HttpWebRequest对象
        HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
        request.Method = "POST";

        // 设置请求头，支持gzip压缩
        request.Headers.Add("Accept-Encoding", "gzip");

        // 压缩请求体
        byte[] compressedData = CompressData(Encoding.UTF8.GetBytes(postData));

        // 设置请求体长度
        request.ContentLength = compressedData.Length;

        // 发送请求
        using (Stream requestStream = request.GetRequestStream())
        {
            requestStream.Write(compressedData, 0, compressedData.Length);
        }

        // 接收响应
        using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())
        {
            // 处理响应
            // ...
        }
    }

    // 使用Gzip算法压缩数据
    private static byte[] CompressData(byte[] data)
    {
        using (MemoryStream memoryStream = new MemoryStream())
        {
            using (GZipStream gzipStream = new GZipStream(memoryStream, CompressionMode.Compress))
            {
                gzipStream.Write(data, 0, data.Length);
            }
            return memoryStream.ToArray();
        }
    }
}