using System;

using System.Collections.Generic;

using System.Data;

using System.IO;

using System.IO.Compression;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace ConsoleApplication1

{

    public class ZipHelper

    {

        /// <summary>

        /// 解压

        /// </summary>

        /// <param name="Value"></param>

        /// <returns></returns>

        public static DataSet GetDatasetByString(string Value)

        {

            DataSet ds = new DataSet();

            string CC = GZipDecompressString(Value);

            System.IO.StringReader Sr = new StringReader(CC);

            ds.ReadXml(Sr);

            return ds;

        }

        /// <summary>

        /// 根据DATASET压缩字符串

        /// </summary>

        /// <param name="ds"></param>

        /// <returns></returns>

        public static string GetStringByDataset(string ds)

        {

            return GZipCompressString(ds);

        }

        /// <summary>

        /// 将传入字符串以GZip算法压缩后，返回Base64编码字符

        /// </summary>

        /// <param name="rawString">需要压缩的字符串</param>

        /// <returns>压缩后的Base64编码的字符串</returns>

        public static string GZipCompressString(string rawString)

        {

            if (string.IsNullOrEmpty(rawString) || rawString.Length == 0)

            {

                return "";

            }

            else

            {

                byte[] rawData = System.Text.Encoding.UTF8.GetBytes(rawString.ToString());

                byte[] zippedData = Compress(rawData);

                return (string)(Convert.ToBase64String(zippedData));

            }

        }

        /// <summary>

        /// GZip压缩

        /// </summary>

        /// <param name="rawData"></param>

        /// <returns></returns>

        public static byte[] Compress(byte[] rawData)

        {

            MemoryStream ms = new MemoryStream();

            GZipStream compressedzipStream = new GZipStream(ms, CompressionMode.Compress, true);

            compressedzipStream.Write(rawData, 0, rawData.Length);

            compressedzipStream.Close();

            return ms.ToArray();

        }

        /// <summary>

        /// 将传入的二进制字符串资料以GZip算法解压缩

        /// </summary>

        /// <param name="zippedString">经GZip压缩后的二进制字符串</param>

        /// <returns>原始未压缩字符串</returns>

        public static string GZipDecompressString(string zippedString)

        {

            if (string.IsNullOrEmpty(zippedString) || zippedString.Length == 0)

            {

                return "";

            }

            else

            {

                byte[] zippedData = Convert.FromBase64String(zippedString.ToString());

                return (string)(System.Text.Encoding.UTF8.GetString(Decompress(zippedData)));

            }

        }

        /// <summary>

        /// ZIP解压

        /// </summary>

        /// <param name="zippedData"></param>

        /// <returns></returns>

        public static byte[] Decompress(byte[] zippedData)

        {

            MemoryStream ms = new MemoryStream(zippedData);

            GZipStream compressedzipStream = new GZipStream(ms, CompressionMode.Decompress);

            MemoryStream outBuffer = new MemoryStream();

            byte[] block = new byte[1024];

            while (true)

            {

                int bytesRead = compressedzipStream.Read(block, 0, block.Length);

                if (bytesRead <= 0)

                    break;

                else

                    outBuffer.Write(block, 0, bytesRead);

            }

            compressedzipStream.Close();

            return outBuffer.ToArray();

        }

    }

}