我正在尝试实施SharpZipLib
所以我从他们的样本中复制了下面的代码片段:
// Compresses the supplied memory stream, naming it as zipEntryName, into a zip,
// which is returned as a memory stream or a byte array.
//
public MemoryStream CreateToMemoryStream(MemoryStream memStreamIn, string zipEntryName)
{
MemoryStream outputMemStream = new MemoryStream();
ZipOutputStream zipStream = new ZipOutputStream(outputMemStream);
zipStream.SetLevel(3); //0-9, 9 being the highest level of compression
ZipEntry newEntry = new ZipEntry(zipEntryName);
newEntry.DateTime = DateTime.Now;
zipStream.PutNextEntry(newEntry);
StreamUtils.Copy(memStreamIn, zipStream, new byte[4096]);
zipStream.CloseEntry();
zipStream.IsStreamOwner = false; // False stops the Close also Closing the underlying stream.
zipStream.Close(); // Must finish the ZipOutputStream before using outputMemStream.
outputMemStream.Position = 0;
return outputMemStream;
// Alternative outputs:
// ToArray is the cleaner and easiest to use correctly with the penalty of duplicating allocated memory.
byte[] byteArrayOut = outputMemStream.ToArray();
// GetBuffer returns a raw buffer raw and so you need to account for the true length yourself.
byte[] byteArrayOut = outputMemStream.GetBuffer();
long len = outputMemStream.Length;
}
我复制粘贴该功能并以这种方式调用它:
using (MemoryStream ms = new MemoryStream())
using (FileStream file = new FileStream(@"c:\file.jpg", FileMode.Open, FileAccess.Read))
{
byte[] bytes = new byte[file.Length];
file.Read(bytes, 0, (int)file.Length);
ms.Write(bytes, 0, (int)file.Length);
var result = SharpZip.CreateToMemoryStream(ms, "file.jpg");
result.WriteTo(new FileStream(@"c:\myzip.zip", FileMode.Create, System.IO.FileAccess.Write));
}
myzip.zip 已成功创建,但file.jpg里面没有字节。
有什么想法吗?
非常感谢
答案 0 :(得分:0)
有必要"倒带"写入输入文件数据后输入MemoryStream
:
using (MemoryStream ms = new MemoryStream())
using (FileStream file = File.OpenRead(@"input file path"))
{
byte[] bytes = new byte[file.Length];
file.Read(bytes, 0, (int)file.Length);
ms.Write(bytes, 0, (int)file.Length);
ms.Position = 0; // "Rewind" the stream to the beginning.
var result = SharpZip.CreateToMemoryStream(ms, "file.jpg");
using (var outputStream = File.Create(@"output file path"))
{
result.WriteTo(outputStream);
}
}
实现的替代(略微简化)版本:
var bytes = File.ReadAllBytes(@"input file path");
using (MemoryStream ms = new MemoryStream(bytes))
{
var result = SharpZip.CreateToMemoryStream(ms, "file.jpg");
using (var outputStream = File.Create(@"output file path"))
{
result.WriteTo(outputStream);
}
}