一尘不染

使用C#压缩/解压缩字符串

c#

我是.net的新手。我正在C#中执行压缩和解压缩字符串。有一个XML,我要转换为字符串,然后进行压缩和解压缩。除了对代码进行解压缩并返回我的字符串时,我的代码中没有编译错误,它仅返回XML的一半。

以下是我的代码,请在错误之处纠正我。

码:

class Program
{
    public static string Zip(string value)
    {
        //Transform string into byte[]  
        byte[] byteArray = new byte[value.Length];
        int indexBA = 0;
        foreach (char item in value.ToCharArray())
        {
            byteArray[indexBA++] = (byte)item;
        }

        //Prepare for compress
        System.IO.MemoryStream ms = new System.IO.MemoryStream();
        System.IO.Compression.GZipStream sw = new System.IO.Compression.GZipStream(ms, System.IO.Compression.CompressionMode.Compress);

        //Compress
        sw.Write(byteArray, 0, byteArray.Length);
        //Close, DO NOT FLUSH cause bytes will go missing...
        sw.Close();

        //Transform byte[] zip data to string
        byteArray = ms.ToArray();
        System.Text.StringBuilder sB = new System.Text.StringBuilder(byteArray.Length);
        foreach (byte item in byteArray)
        {
            sB.Append((char)item);
        }
        ms.Close();
        sw.Dispose();
        ms.Dispose();
        return sB.ToString();
    }

    public static string UnZip(string value)
    {
        //Transform string into byte[]
        byte[] byteArray = new byte[value.Length];
        int indexBA = 0;
        foreach (char item in value.ToCharArray())
        {
            byteArray[indexBA++] = (byte)item;
        }

        //Prepare for decompress
        System.IO.MemoryStream ms = new System.IO.MemoryStream(byteArray);
        System.IO.Compression.GZipStream sr = new System.IO.Compression.GZipStream(ms,
            System.IO.Compression.CompressionMode.Decompress);

        //Reset variable to collect uncompressed result
        byteArray = new byte[byteArray.Length];

        //Decompress
        int rByte = sr.Read(byteArray, 0, byteArray.Length);

        //Transform byte[] unzip data to string
        System.Text.StringBuilder sB = new System.Text.StringBuilder(rByte);
        //Read the number of bytes GZipStream red and do not a for each bytes in
        //resultByteArray;
        for (int i = 0; i < rByte; i++)
        {
            sB.Append((char)byteArray[i]);
        }
        sr.Close();
        ms.Close();
        sr.Dispose();
        ms.Dispose();
        return sB.ToString();
    }

    static void Main(string[] args)
    {
        XDocument doc = XDocument.Load(@"D:\RSP.xml");
        string val = doc.ToString(SaveOptions.DisableFormatting);
        val = Zip(val);
        val = UnZip(val);
    }
}

我的XML大小为63KB。


阅读 330

收藏
2020-05-19

共1个答案

一尘不染

压缩/解压缩字符串的代码

public static void CopyTo(Stream src, Stream dest) {
    byte[] bytes = new byte[4096];

    int cnt;

    while ((cnt = src.Read(bytes, 0, bytes.Length)) != 0) {
        dest.Write(bytes, 0, cnt);
    }
}

public static byte[] Zip(string str) {
    var bytes = Encoding.UTF8.GetBytes(str);

    using (var msi = new MemoryStream(bytes))
    using (var mso = new MemoryStream()) {
        using (var gs = new GZipStream(mso, CompressionMode.Compress)) {
            //msi.CopyTo(gs);
            CopyTo(msi, gs);
        }

        return mso.ToArray();
    }
}

public static string Unzip(byte[] bytes) {
    using (var msi = new MemoryStream(bytes))
    using (var mso = new MemoryStream()) {
        using (var gs = new GZipStream(msi, CompressionMode.Decompress)) {
            //gs.CopyTo(mso);
            CopyTo(gs, mso);
        }

        return Encoding.UTF8.GetString(mso.ToArray());
    }
}

static void Main(string[] args) {
    byte[] r1 = Zip("StringStringStringStringStringStringStringStringStringStringStringStringStringString");
    string r2 = Unzip(r1);
}

请记住,Zip返回byte[],而Unzip返回string。如果您想要一个字符串,Zip可以对它进行Base64编码(例如,使用Convert.ToBase64String(r1))(结果Zip是非常二进制的!则不能将其打印到屏幕上或直接以XML编写)

建议的版本适用于.NET 2.0,适用于.NET 4.0使用MemoryStream.CopyTo

重要说明:
GZipStream知道压缩内容具有所有输入之前(即,有效压缩它需要所有数据),才能将压缩内容写入输出流。在检查输出流(例如)之前,需要确保您Dispose()的身份。这是通过上面的块完成的。请注意,是最里面的块,并且可以在其外部访问内容。这同样适用于解压缩:在中尝试访问之前的数据。GZipStream``mso.ToArray()``using() { }``GZipStream``Dispose()``GZipStream

2020-05-19