Heim  >  Artikel  >  Backend-Entwicklung  >  Komprimierung und Dekomprimierung des C#-Dateistreams

Komprimierung und Dekomprimierung des C#-Dateistreams

黄舟
黄舟Original
2017-02-13 11:52:282605Durchsuche

 /// <summary>
    /// 文件流压缩解压
    /// </summary>
    public class ZipHelper
    {
        public static int BEST_COMPRESSION = 9;
        public static int BEST_SPEED = 1;
        public static int DEFAULT_COMPRESSION = -1;
        public static int NO_COMPRESSION = 0;

        #region  Deflate压缩

        #region Deflate压缩
        /// <summary>
        /// Deflate方式压缩(默认压缩级别最高)
        /// </summary>
        /// <param name="stream"></param>
        /// <returns></returns>
        public static Stream Deflate(Stream stream)
        {
            return ZipHelper.Deflate(stream, ZipHelper.DEFAULT_COMPRESSION);
        }
        /// <summary>
        ///  Deflate方式压缩
        /// </summary>
        /// <param name="stream"></param>
        /// <param name="level">压缩品质级别(0~9)</param>
        /// <returns></returns>
        public static Stream Deflate(Stream stream, int level)
        {
            byte[] array = ZipHelper.StreamToBytes(stream);
            byte[] array2 = new byte[array.Length];
            Deflater deflater = new Deflater();
            deflater.SetLevel(level);
            deflater.SetStrategy(DeflateStrategy.Default);
            deflater.SetInput(array);
            deflater.Finish();
            int num = deflater.Deflate(array2);
            byte[] array3 = new byte[num];
            Array.Copy(array2, array3, num);
            return ZipHelper.BytesToStream(array3);
        }

        /// <summary>
        /// Deflate方式压缩
        /// </summary>
        /// <param name="input"></param>
        /// <param name="level">压缩品质级别(0~9)</param>
        /// <returns></returns>
        public static byte[] Deflate(byte[] input, int level)
        {
            byte[] result;
            try
            {
                if (input == null && input.Length == 0)
                {
                    result = new byte[0];
                }
                else
                {
                    byte[] array = new byte[input.Length];
                    Deflater deflater = new Deflater();
                    deflater.SetLevel(level);
                    deflater.SetStrategy(DeflateStrategy.Default);
                    deflater.SetInput(input);
                    deflater.Finish();
                    int num = deflater.Deflate(array);
                    byte[] array2 = new byte[num];
                    Array.Copy(array, array2, num);
                    result = array2;
                }
            }
            catch (Exception innerException)
            {
                throw new Exception("压缩程序出错!", innerException);
            }
            return result;
        }
        #endregion

        #region Inflate解压
        /// <summary>
        /// Inflate解压
        /// </summary>
        /// <param name="input"></param>
        /// <returns></returns>
        public static byte[] Inflate(byte[] input)
        {
            byte[] result;
            try
            {
                if (input == null && input.Length == 0)
                {
                    result = new byte[0];
                }
                else
                {
                    Inflater inflater = new Inflater();
                    inflater.SetInput(input);
                    byte[] array = new byte[1024];
                    using (MemoryStream memoryStream = new MemoryStream())
                    {
                        for (int i = inflater.Inflate(array, 0, array.Length); i > 0; i = inflater.Inflate(array, 0, array.Length))
                        {
                            memoryStream.Write(array, 0, i);
                        }
                        byte[] buffer = memoryStream.GetBuffer();
                        memoryStream.Close();
                        result = buffer;
                    }
                }
            }
            catch (Exception innerException)
            {
                throw new Exception("解压缩程序出错!", innerException);
            }
            return result;
        }
        /// <summary>
        /// Inflate解压
        /// </summary>
        /// <param name="zipStream"></param>
        /// <returns></returns>
        public static Stream Inflate(Stream zipStream)
        {
            byte[] input = ZipHelper.StreamToBytes(zipStream);
            byte[] bytes = ZipHelper.Inflate(input);
            return ZipHelper.BytesToStream(bytes);
        }
        #endregion

        #endregion

        #region GZip压缩
        /// <summary>
        /// GZip压缩
        /// </summary>
        /// <param name="srcStream"></param>
        /// <param name="output"></param>
        public static void GZipCompress(Stream srcStream, Stream output)
        {
            ZipHelper.GZipCompress(srcStream, 6, output);
        }
        /// <summary>
        ///  GZip压缩
        /// </summary>
        /// <param name="srcStream"></param>
        /// <param name="compressLevel">压缩品质级别(0~9)</param>
        /// <param name="output"></param>
        public static void GZipCompress(Stream srcStream, int compressLevel, Stream output)
        {
            if (compressLevel < 1 || compressLevel > 9)
            {
                throw new Exception(string.Format("您指定的压缩级别 {0} 不在有效的范围(1-9)内", compressLevel));
            }
            srcStream.Position = 0L;
            GZipOutputStream gZipOutputStream = new GZipOutputStream(output);
            gZipOutputStream.SetLevel(compressLevel);
            try
            {
                int i = 4096;
                byte[] buffer = new byte[i];
                while (i > 0)
                {
                    i = srcStream.Read(buffer, 0, i);
                    gZipOutputStream.Write(buffer, 0, i);
                }
            }
            catch (Exception ex)
            {
                throw new Exception("GZip压缩出错:" + ex.Message);
            }
            srcStream.Close();
            gZipOutputStream.Finish();
        }
        /// <summary>
        ///  GZip解压
        /// </summary>
        /// <param name="zipStream"></param>
        /// <param name="outputStream"></param>
        public static void GZipDeCompress(Stream zipStream, Stream outputStream)
        {
            GZipInputStream gZipInputStream = new GZipInputStream(zipStream);
            try
            {
                int i = 4096;
                byte[] buffer = new byte[i];
                while (i > 0)
                {
                    i = gZipInputStream.Read(buffer, 0, i);
                    outputStream.Write(buffer, 0, i);
                }
            }
            catch (Exception ex)
            {
                throw new Exception("GZip解压缩出错:" + ex.Message);
            }
            zipStream.Close();
            gZipInputStream.Close();
        }
        #endregion

        #region  BZip2压缩
        /// <summary>
        /// BZip2压缩
        /// </summary>
        /// <param name="inStream"></param>
        /// <param name="outStream"></param>
        /// <param name="blockSize"></param>
        public static void BZip2Compress(Stream inStream, Stream outStream, int blockSize)
        {
            BZip2.Compress(inStream, outStream, blockSize);
        }
        /// <summary>
        /// BZip2解压
        /// </summary>
        /// <param name="inStream"></param>
        /// <param name="outStream"></param>
        public static void BZip2Decompress(Stream inStream, Stream outStream)
        {
            BZip2.Decompress(inStream, outStream);
        }
        #endregion


        private static byte[] StreamToBytes(Stream stream)
        {
            byte[] array = new byte[stream.Length];
            stream.Seek(0L, SeekOrigin.Begin);
            stream.Read(array, 0, array.Length);
            stream.Close();
            return array;
        }
        private static Stream BytesToStream(byte[] bytes)
        {
            return new MemoryStream(bytes);
        }
        private static void StreamToFile(Stream stream, string fileName)
        {
            byte[] array = new byte[stream.Length];
            stream.Read(array, 0, array.Length);
            stream.Seek(0L, SeekOrigin.Begin);
            FileStream fileStream = new FileStream(fileName, FileMode.Create);
            BinaryWriter binaryWriter = new BinaryWriter(fileStream);
            binaryWriter.Write(array);
            binaryWriter.Close();
            fileStream.Close();
        }
        private static Stream FileToStream(string fileName)
        {
            FileStream fileStream = new FileStream(fileName, FileMode.Open, FileAccess.Read, FileShare.Read);
            byte[] array = new byte[fileStream.Length];
            fileStream.Read(array, 0, array.Length);
            fileStream.Close();
            return new MemoryStream(array);
        }
    }

Das Obige ist der Inhalt der C#-Dateistream-Komprimierung und -Dekomprimierung. Weitere verwandte Inhalte finden Sie auf der chinesischen PHP-Website (www.php.cn).

Stellungnahme:
Der Inhalt dieses Artikels wird freiwillig von Internetnutzern beigesteuert und das Urheberrecht liegt beim ursprünglichen Autor. Diese Website übernimmt keine entsprechende rechtliche Verantwortung. Wenn Sie Inhalte finden, bei denen der Verdacht eines Plagiats oder einer Rechtsverletzung besteht, wenden Sie sich bitte an admin@php.cn
Vorheriger Artikel:C# Protobuf-Net-SerialisierungNächster Artikel:C# Protobuf-Net-Serialisierung