Gzip在c#中压缩和解压缩

本文关键字：解压缩 压缩 Gzip | 更新日期: 2023-09-27 18:16:46

我试图在一个模块中压缩字符串并在另一个模块中解压缩它。这是我正在使用的代码。

压缩
public static string CompressString(string text)
{
    byte[] buffer = Encoding.ASCII.GetBytes(text);
    MemoryStream ms = new MemoryStream();
    using (GZipStream zip = new GZipStream(ms, CompressionMode.Compress, true))
    {
         zip.Write(buffer, 0, buffer.Length);
    }
    ms.Position = 0;
    MemoryStream outStream = new MemoryStream();
    byte[] compressed = new byte[ms.Length];
    ms.Read(compressed, 0, compressed.Length);
    byte[] gzBuffer = new byte[compressed.Length + 4];
    System.Buffer.BlockCopy(compressed, 0, gzBuffer, 4, compressed.Length);
    System.Buffer.BlockCopy(BitConverter.GetBytes(buffer.Length), 0, gzBuffer, 0, 4);
    return Convert.ToBase64String(gzBuffer);
}

解压

public static byte[] DecompressString(byte[] data)
{
   using (var compressedStream = new MemoryStream(data))
   using (var zipStream = new GZipStream(compressedStream, CompressionMode.Decompress))
     using (var resultStream = new MemoryStream())
     {
        zipStream.CopyTo(resultStream);
        return resultStream.ToArray();
     }
}

使用它作为:

 DecompressString(System.Text.Encoding.ASCII.GetBytes(ip));

但是，对于上面的语句，我得到以下错误:

{" GZip头中的神奇数字不正确。确保你是传入一个GZip流。"}系统。SystemException{System.IO.InvalidDataException}

Gzip在c#中压缩和解压缩

这是重写的代码，它应该按照你想要的方式工作。

我是用LINQPad写的，可以在里面测试。

注意这里很少有错误检查。您应该添加检查，以查看所有读操作是否完成，并实际读取了它们应该读取的内容，以及类似的检查。

original: 256
This is a test. This is a test. This is a test. This is a test. This is a test. This is a test. This is a test. This is a test. This is a test. This is a test. This is a test. This is a test. This is a test. This is a test. This is a test. This is a test.  
compressed: 56
AAEAAB+LCAAAAAAABAALycgsVgCiRIWS1OISPYWQEcYHANU9d5YAAQAA 
decompressed: 256
This is a test. This is a test. This is a test. This is a test. This is a test. This is a test. This is a test. This is a test. This is a test. This is a test. This is a test. This is a test. This is a test. This is a test. This is a test. This is a test.
项目

void Main()
{
    var input = "This is a test. This is a test. ";
    input += input;
    input += input;
    input += input;
    string compressed = Compress(input);
    string decompressed = Decompress(compressed);
    input.Dump("original: " + input.Length);
    compressed.Dump("compressed: " + compressed.Length);
    decompressed.Dump("decompressed: " + decompressed.Length);
}
public static string Decompress(string input)
{
    byte[] compressed = Convert.FromBase64String(input);
    byte[] decompressed = Decompress(compressed);
    return Encoding.UTF8.GetString(decompressed);
}
public static string Compress(string input)
{
    byte[] encoded = Encoding.UTF8.GetBytes(input);
    byte[] compressed = Compress(encoded);
    return Convert.ToBase64String(compressed);
}
public static byte[] Decompress(byte[] input)
{
    using (var source = new MemoryStream(input))
    {
        byte[] lengthBytes = new byte[4];
        source.Read(lengthBytes, 0, 4);
        var length = BitConverter.ToInt32(lengthBytes, 0);
        using (var decompressionStream = new GZipStream(source,
            CompressionMode.Decompress))
        {
            var result = new byte[length];
            decompressionStream.Read(result, 0, length);
            return result;
        }
    }
}
public static byte[] Compress(byte[] input)
{
    using (var result = new MemoryStream())
    {
        var lengthBytes = BitConverter.GetBytes(input.Length);
        result.Write(lengthBytes, 0, 4);
        using (var compressionStream = new GZipStream(result,
            CompressionMode.Compress))
        {
            compressionStream.Write(input, 0, input.Length);
            compressionStream.Flush();
        }
        return result.ToArray();
    }
}

。. NET 6+解决方案(修复https://github.com/dotnet/runtime/issues/64577):

)
void Main()
{
    var input = "This is a test. This is a test. ";
    input += input;
    input += input;
    input += input;
    string compressed = Compress(input);
    string decompressed = Decompress(compressed);
    input.Dump("original: " + input.Length);
    compressed.Dump("compressed: " + compressed.Length);
    decompressed.Dump("decompressed: " + decompressed.Length);
}
public static string Decompress(string input)
{
    byte[] compressed = Convert.FromBase64String(input);
    byte[] decompressed = Decompress(compressed);
    return Encoding.UTF8.GetString(decompressed);
}
public static string Compress(string input)
{
    byte[] encoded = Encoding.UTF8.GetBytes(input);
    byte[] compressed = Compress(encoded);
    return Convert.ToBase64String(compressed);
}
public static byte[] Decompress(byte[] input)
{
    using (var source = new MemoryStream(input))
    {
        byte[] lengthBytes = new byte[4];
        source.Read(lengthBytes, 0, 4);
        var length = BitConverter.ToInt32(lengthBytes, 0);
        using (var decompressionStream = new GZipStream(source,
            CompressionMode.Decompress))
        {
            var result = new byte[length];
            int totalRead = 0, bytesRead;
            while ((bytesRead = decompressionStream.Read(result, totalRead, length - totalRead)) > 0)
            {
              totalRead += bytesRead;
            }
            return result;
        }
    }
}
public static byte[] Compress(byte[] input)
{
    using (var result = new MemoryStream())
    {
        var lengthBytes = BitConverter.GetBytes(input.Length);
        result.Write(lengthBytes, 0, 4);
        using (var compressionStream = new GZipStream(result,
            CompressionMode.Compress))
        {
            compressionStream.Write(input, 0, input.Length);
            compressionStream.Flush();
        }
        return result.ToArray();
    }
}
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