Practical experience in sharpzip compression and decompression

This article was originally a post I posted on the csdn Forum (http://search.csdn.net/expert/topicview1.asp? Id = 2377844), and now it is "Shun" (whole) into a chapter.

 

First, download the source code in the http://www.icsharpcode.net/OpenSource/SharpZipLib/Default.aspx, find the "zipconstants. cs" Change

Public static string converttostring (byte [] data)
{
Return encoding. getencoding ("gb2312"). getstring (data, 0, Data. Length );
// Return encoding. ASCII. getstring (data, 0, Data. Length );
}

Public static byte [] converttoarray (string Str)
{
Return encoding. getencoding ("gb2312"). getbytes (STR );
// Return encoding. ASCII. getbytes (STR );
}

Chinese names are supported.
The following is my compressed and decompressed code:

Using system;
Using system. collections;
Using system. componentmodel;
Using system. Data;
Using system. drawing;
Using system. Web;
Using system. Web. sessionstate;
Using system. Web. UI;
Using system. Web. UI. webcontrols;
Using system. Web. UI. htmlcontrols;
Using icsharpcode. sharpziplib. Zip;

Namespace OA
{
/// <Summary>
/// Summary of webform1.
/// </Summary>
Public class webform1: system. Web. UI. Page
{
Public String serverdir;
Private void page_load (Object sender, system. eventargs E)
{
// Place user code here to initialize the page
This. serverdir = page. mappath (".");
This. zipfile ("01.txt * 02.txt * 000.zip"); // It is just an example. You can implement it yourself.
This. zipfile ("01.txt * 02.txt * 001.zip ");
This. unzipfile ("000.zip * 001.zip ");
}

Public String includir (string S)
{
// Convert the absolute path of the object to the relative path
String d = S. Replace (serverdir ,"");
Return D;
}

// Compressed file P is the list of files uploaded by the client: file name + compressed package name
Public void zipfile (string P)
{
String [] TMP = P. Split (New char [] {'*'}); // list of Separated Files
If (TMP [TMP. Length-1]! = "") // The compressed package name is not blank
{
Zipoutputstream u = new zipoutputstream (file. Create (serverdir + TMP [TMP. Length-1]); // create a compressed file stream "zipoutputstream"
For (INT I = 0; I <TMP. Length-1; I ++)
{
If (TMP [I]! = "") // The separated file name is not empty.
{
This. addzipentry (TMP [I], U, out U); // add content to the compressed file stream
}
}
U. Finish (); // end Compression
U. Close ();
}
}

// Add a compression project: P is the file or folder to be compressed; U is the existing source zipoutputstream; out J is the "zipoutputstream" that has been added with "zipentry"
Public void addzipentry (string P, zipoutputstream U, out zipoutputstream J)
{
String S = serverdir + P;

If (directory. exists (s) // process the folder
{
Directoryinfo di = new directoryinfo (s );

// *********** The following content is added after the amendment ***********

If (Di. getdirectories (). Length <= 0) // No subdirectory
{
Zipentry z = new zipentry (p + "\"); // The End "\" is used for folder tag
U. putnextentry (z );
}

// ************** The above content is added after the revision ***************

Foreach (directoryinfo TEM in Di. getdirectories () // obtain the subdirectory
{
Zipentry z = new zipentry (this. Partial Dir (TEM. fullname) + "\"); // The End "\" is used for folder tag
U. putnextentry (z); // This sentence is indispensable; otherwise, the empty directory will not be added.
S = This. Partial Dir (TEM. fullname );
This. addzipentry (S, U, out U); // Recursion
}
Foreach (fileinfo temp in Di. getfiles () // get the files in this directory
{
S = This. Partial Dir (temp. fullname );
This. addzipentry (S, U, out U); // Recursion
}
}
Else if (file. exists (s) // File Processing
{
U. setlevel (9); // compression level
Filestream F = file. openread (s );
Byte [] B = new byte [F. Length];
F. Read (B, 0, B. Length); // Add the file stream to the buffer byte
Zipentry z = new zipentry (this. Partial Dir (s ));
U. putnextentry (z); // provides a container for the compressed file stream
U. Write (B, 0, B. Length); // write bytes
F. Close ();
}
J = u; // return the "zipoutputstream" of the added data"
}

Public void unzipfile (string p) // Extract
{
String [] un_tmp = P. Split (New char [] {'*'});
Int I2 = 0; // a parameter that prevents Name Conflict
For (Int J = 0; j <un_tmp.length; j ++)
{
If (un_tmp [J]! = "")
{
String un_time = system. datetime. now. toshortdatestring () + "-" + system. datetime. now. hour. tostring () + "-" + system. datetime. now. minute. tostring () + "-" + (system. datetime. now. second + I2 ). tostring ();
String un_dir = serverdir + "Unzip-" + un_time;
Directory. createdirectory (un_dir); // create a folder named after the extract time
Zipinputstream F = new zipinputstream (file. openread (serverdir + un_tmp [J]); // read the compressed file and use this file stream to create a "zipinputstream" object

A: zipentry ZP = f. getnextentry (); // obtain the project in the decompressed file stream. Note (my understanding): Each file in the compressed package exists in the form of "zipentry", including the directory information for storing the file. If the empty directory is compressed, a "file" named empty, with a size of 0 and a CRC attribute of 00000000 will appear in the directory ". This file is only a tag and will not be decompressed.

While (ZP! = NULL)
{
String un_tmp2;
If (ZP. Name. indexof ("\")> = 0) // obtain the directory information of the object
{
Int tmp1 = ZP. Name. lastindexof ("\\");
Un_tmp2 = ZP. Name. substring (0, tmp1 );
Directory. createdirectory (un_dir + "\" + un_tmp2 + "\"); // you must first create a directory; otherwise, decompression fails --- (a) is related to the following steps (B)
}
If (! ZP. isdirectory & ZP. CRC! = 00000000l) // This "zipentry" is not "Tag file"
{
Int I = 2048;
Byte [] B = new byte [I]; // buffer 2048 bytes each time
Filestream S = file. Create (un_dir + "\" + ZP. Name); // (B)-create a file stream
While (true) // read bytes continuously until a "zipentry" byte is read
{
I = f. Read (B, 0, B. Length); // read the byte in "zipentry"
If (I> 0)
{
S. Write (B, 0, I); // write bytes to the new file stream
}
Else
{
Break; // The read byte is 0.
}
}
S. Close ();
}
Goto A; // enter the next "zipentry"
}
F. Close ();
I2 ++;
}
}
}
}
}

 

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