c# - GZipStream 和解压

Question

我有应该进行压缩的代码:

FileStream fs = new FileStream("g:\\gj.txt", FileMode.Open);
FileStream fd = new FileStream("g:\\gj.zip", FileMode.Create);
GZipStream csStream = new GZipStream(fd, CompressionMode.Compress);

byte[] compressedBuffer = new byte[500];
int offset = 0;
int nRead;

nRead = fs.Read(compressedBuffer, offset, compressedBuffer.Length);
while (nRead > 0)
{
    csStream.Write(compressedBuffer, offset, nRead);
    offset = offset + nRead;
    nRead = fs.Read(compressedBuffer, offset, compressedBuffer.Length);
}

fd.Close();
fs.Close();

我认为是这样，但我想解压缩按上述方式压缩的内容。我是这样想的:

FileStream fd = new FileStream("g:\\gj.new", FileMode.Create);
FileStream fs = new FileStream("g:\\gj.zip", FileMode.Open);
GZipStream csStream = new GZipStream(fs, CompressionMode.Decompress);

byte[] decompressedBuffer = new byte[500];
int offset = 0;
int nRead;

nRead=csStream.Read(decompressedBuffer, offset, decompressedBuffer.Length);
while (nRead > 0)
{
    fd.Write(decompressedBuffer, offset, nRead);
    offset = offset + nRead;
    nRead = csStream.Read(decompressedBuffer, offset, decompressedBuffer.Length);
}

fd.Close();
fs.Close();

这里没有...我在进入循环之前得到了 nRead = 0...我做错了什么？我使用的测试文件是最简单的TEXT文件(大小:104字节)...

Answer 1

我的第一个想法是你还没有关闭csStream。如果你使用 using 这会自动发生。由于 gzip 缓冲数据，您可能会丢失一些数据。

其次；不要增加 offset；那是 buffer(不是流)中的偏移量。离开 0:

using (Stream fs = File.OpenRead("gj.txt"))
using (Stream fd = File.Create("gj.zip"))
using (Stream csStream = new GZipStream(fd, CompressionMode.Compress))
{
    byte[] buffer = new byte[1024];
    int nRead;
    while ((nRead = fs.Read(buffer, 0, buffer.Length))> 0)
    {
        csStream.Write(buffer, 0, nRead);
    }
}

using (Stream fd = File.Create("gj.new.txt"))
using (Stream fs = File.OpenRead("gj.zip"))
using (Stream csStream = new GZipStream(fs, CompressionMode.Decompress))
{
    byte[] buffer = new byte[1024];
    int nRead;
    while ((nRead = csStream.Read(buffer, 0, buffer.Length)) > 0)
    {
        fd.Write(buffer, 0, nRead);
    }
}