用ASP.Net實現檔案的在線壓縮和解壓縮

　　我們經常會遇到批量上傳的問題，也會遇到將某個目錄下所有檔案都上傳到伺服器上的問題。那麼，如何解決此類問題呢？以前的技術一般採用ActiveX等方式，這裡筆者採用SharpZlib來實現，聽說VS2005已有壓縮和解壓縮的解決方案，筆者還沒有時間用VS2005，所以就只好使用VS2003 + SharpZlib來解決問題了。

　　1、首先從這裡下載0.84版本的SharpZlib源碼及樣本碼。
　　2、下載下來之後你發現它沒有VS2003的解決方案檔案，沒有關係。你可以自己建立，首先建立一個ZipUnzip的解決方案，然後，將上面經過解壓縮之後的所有檔案及目錄COPY到你的解決方案所在的目錄下。
　　3、在VS2003方案總管（一般是在右上方中部點的位置）中點擊顯示所有檔案按鈕，然後可以見到很多“虛”的表徵圖、檔案及檔案夾等，可以一次選擇它們，然後包含進項目中。
　　4、編譯，最好使用Release選項，編譯完成之後你可以在\bin\Release\看到ZipUnzip.dll的類了。如果你編譯時間報錯，說什麼AssemblyKeyFile之類的，你可以使用強命名工具建立一個，也可以將AssemblyInfo.cs中[assembly: AssemblyKeyFile("。。。。。")]改成:[assembly: AssemblyKeyFile("")] (不推薦這樣做)。
　　5、建立一個WEBFORM項目，添加ZipUnzip.dll類的引用，然後添加如下檔案及內容：

// ------------------------------------------
// 1. AttachmentUnZip.cs
// ------------------------------------------
using System;
using System.IO;
using ICSharpCode.SharpZipLib.Zip;
using ICSharpCode.SharpZipLib.GZip;
using ICSharpCode.SharpZipLib.BZip2;
using ICSharpCode.SharpZipLib.Checksums;
using ICSharpCode.SharpZipLib.Zip.Compression;
using ICSharpCode.SharpZipLib.Zip.Compression.Streams;

namespace WebZipUnzip
{
public class AttachmentUnZip
{
public AttachmentUnZip()
{
}
public static void UpZip(string zipFile)
{
string []FileProperties=new string[2];
FileProperties[0]=zipFile;//待解壓的檔案
FileProperties[1]=zipFile.Substring(0,zipFile.LastIndexOf("\\")+1);//解壓後放置的目標目錄
UnZipClass UnZc=new UnZipClass();
UnZc.UnZip(FileProperties);
}
}
}

// ---------------------------------------------
// 2. UnZipClass.cs
// ---------------------------------------------

using System;
using System.IO;
using ICSharpCode.SharpZipLib.Zip;
using ICSharpCode.SharpZipLib.GZip;
using ICSharpCode.SharpZipLib.BZip2;
using ICSharpCode.SharpZipLib.Checksums;
using ICSharpCode.SharpZipLib.Zip.Compression;
using ICSharpCode.SharpZipLib.Zip.Compression.Streams;

namespace WebZipUnzip
{
public class UnZipClass
{
/// <summary>
/// 解壓檔案
/// </summary>
/// <param name="args">包含要解壓的檔案名稱和要解壓到的目錄名數組</param>
public void UnZip(string[] args)
{
ZipInputStream s = new ZipInputStream(File.OpenRead(args[0]));
try
{
ZipEntry theEntry;
while ((theEntry = s.GetNextEntry()) != null)
{
string directoryName = Path.GetDirectoryName(args[1]);
string fileName = Path.GetFileName(theEntry.Name);

//產生解壓目錄
Directory.CreateDirectory(directoryName);

if (fileName != String.Empty)
{
//解壓檔案到指定的目錄
FileStream streamWriter = File.Create(args[1]+fileName);

int size = 2048;
byte[] data = new byte[2048];
while (true)
{
size = s.Read(data, 0, data.Length);
if (size > 0)
{
streamWriter.Write(data, 0, size);
}
else
{
break;
}
}

streamWriter.Close();
}
}
s.Close();
}
catch(Exception eu)
{
throw eu;
}
finally
{
s.Close();
}

}//end UnZip

public static bool UnZipFile(string file, string dir)
{
try
{
if (!Directory.Exists(dir))
Directory.CreateDirectory(dir);
string fileFullName = Path.Combine(dir,file);
ZipInputStream s = new ZipInputStream(File.OpenRead( fileFullName ));

ZipEntry theEntry;
while ((theEntry = s.GetNextEntry()) != null)
{
string directoryName = Path.GetDirectoryName(theEntry.Name);
string fileName = Path.GetFileName(theEntry.Name);

if (directoryName != String.Empty)
Directory.CreateDirectory( Path.Combine(dir, directoryName));

if (fileName != String.Empty)
{
FileStream streamWriter = File.Create( Path.Combine(dir,theEntry.Name) );
int size = 2048;
byte[] data = new byte[2048];
while (true)
{
size = s.Read(data, 0, data.Length);
if (size > 0)
{
streamWriter.Write(data, 0, size);
}
else
{
break;
}
}

streamWriter.Close();
}
}
s.Close();
return true;
}
catch (Exception)
{
throw;
}
}

}//end UnZipClass
}

// ----------------------------------------------
// 3. ZipClass.cs
// ----------------------------------------------
using System;
using System.IO;
using ICSharpCode.SharpZipLib.Zip;
using ICSharpCode.SharpZipLib.GZip;
using ICSharpCode.SharpZipLib.BZip2;
using ICSharpCode.SharpZipLib.Checksums;
using ICSharpCode.SharpZipLib.Zip.Compression;
using ICSharpCode.SharpZipLib.Zip.Compression.Streams;

namespace WebZipUnzip
{
/// <summary>
/// 壓縮檔
/// </summary>
public class ZipClass
{
public void ZipFile(string FileToZip, string ZipedFile ,int CompressionLevel, int BlockSize,string password)
{
//如果檔案沒有找到，則報錯
if (! System.IO.File.Exists(FileToZip))
{
throw new System.IO.FileNotFoundException("The specified file " + FileToZip + " could not be found. Zipping aborderd");
}

System.IO.FileStream StreamToZip = new System.IO.FileStream(FileToZip,System.IO.FileMode.Open , System.IO.FileAccess.Read);
System.IO.FileStream ZipFile = System.IO.File.Create(ZipedFile);
ZipOutputStream ZipStream = new ZipOutputStream(ZipFile);
ZipEntry ZipEntry = new ZipEntry("ZippedFile");
ZipStream.PutNextEntry(ZipEntry);
ZipStream.SetLevel(CompressionLevel);
byte[] buffer = new byte[BlockSize];
System.Int32 size =StreamToZip.Read(buffer,0,buffer.Length);
ZipStream.Write(buffer,0,size);
try
{
while (size < StreamToZip.Length)
{
int sizeRead =StreamToZip.Read(buffer,0,buffer.Length);
ZipStream.Write(buffer,0,sizeRead);
size += sizeRead;
}
}
catch(System.Exception ex)
{
throw ex;
}
ZipStream.Finish();
ZipStream.Close();
StreamToZip.Close();
}

public void ZipFileMain(string[] args)
{
//string[] filenames = Directory.GetFiles(args[0]);
string[] filenames = new string[]{args[0]};

Crc32 crc = new Crc32();
ZipOutputStream s = new ZipOutputStream(File.Create(args[1]));

s.SetLevel(6); // 0 - store only to 9 - means best compression

foreach (string file in filenames)
{
//開啟壓縮檔
FileStream fs = File.OpenRead(file);
byte[] buffer = new byte[fs.Length];
fs.Read(buffer, 0, buffer.Length);
ZipEntry entry = new ZipEntry(file);

entry.DateTime = DateTime.Now;

// set Size and the crc, because the information
// about the size and crc should be stored in the header
// if it is not set it is automatically written in the footer.
// (in this case size == crc == -1 in the header)
// Some ZIP programs have problems with zip files that don't store
// the size and crc in the header.
entry.Size = fs.Length;
fs.Close();

crc.Reset();
crc.Update(buffer);

entry.Crc = crc.Value;

s.PutNextEntry(entry);

s.Write(buffer, 0, buffer.Length);

}
s.Finish();
s.Close();
}
}
}

// ---------------------------------------------
// 4. WebForm1.aspx
// ---------------------------------------------
<%@ Page language="c#" Codebehind="WebForm1.aspx.cs" AutoEventWireup="false" Inherits="WebZipUnzip.WebForm1" %>
<META content="Microsoft Visual Studio .NET 7.1" name=GENERATOR>
<META content=C# name=CODE_LANGUAGE>
<META content=JavaScript name=vs_defaultClientScript>
<META content=http://schemas.microsoft.com/intellisense/ie5 name=vs_targetSchema>
<FORM id=Form1 method=post runat="server"><?xml:namespace prefix = asp /><asp:Button id=Button1 style="Z-INDEX: 101; LEFT: 56px; POSITION: absolute; TOP: 64px" runat="server" Text="壓縮"></asp:Button><asp:Button id=Button2 style="Z-INDEX: 102; LEFT: 112px; POSITION: absolute; TOP: 64px" runat="server" Text="解壓"></asp:Button><INPUT id=File1 style="Z-INDEX: 103; LEFT: 32px; POSITION: absolute; TOP: 24px" type=file name=File1 runat="server"> </FORM></BODY></HTML>

//-------------------------------------------
// 5.WebForm1.aspx.cs
//-------------------------------------------

using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.IO;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;

namespace WebZipUnzip
{
/// <summary>
/// Summary description for WebForm1.
/// </summary>
public class WebForm1 : System.Web.UI.Page
{
protected System.Web.UI.WebControls.Button Button1;
protected System.Web.UI.HtmlControls.HtmlInputFile File1;
protected System.Web.UI.WebControls.Button Button2;

private void Page_Load(object sender, System.EventArgs e)
{
// Put user code to initialize the page here
}

#region Web Form Designer generated code
override protected void OnInit(EventArgs e)
{
//
// CODEGEN: This call is required by the ASP.NET Web Form Designer.
//
InitializeComponent();
base.OnInit(e);
}

/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
private void InitializeComponent()
{
this.Button1.Click += new System.EventHandler(this.Button1_Click);
this.Button2.Click += new System.EventHandler(this.Button2_Click);
this.Load += new System.EventHandler(this.Page_Load);

}
#endregion

#region 壓縮
private void Button1_Click(object sender, System.EventArgs e)
{
string []FileProperties=new string[2];
string fullName=this.File1.PostedFile.FileName;//C:\test\a.txt
string destPath=System.IO.Path.GetDirectoryName(fullName);//C:\test
//待壓縮檔
FileProperties[0]=fullName;

//壓縮後的目標檔案
FileProperties[1]= destPath +"\\"+ System.IO.Path.GetFileNameWithoutExtension(fullName) + ".zip";
ZipClass Zc=new ZipClass();
Zc.ZipFileMain(FileProperties);

//刪除壓縮前的檔案
System.IO.File.Delete(fullName);
}

#endregion

#region 解壓
private void Button2_Click(object sender, System.EventArgs e)
{
string fullName=this.File1.PostedFile.FileName;//C:\test\a.zip
//解壓檔案
//AttachmentUnZip.UpZip(fullName);

// string[] FileProperties = new string[2];
// FileProperties[0] = fullName;//待解壓的檔案
// FileProperties[1] = System.IO.Path.GetDirectoryName(fullName);//解壓後放置的目標目錄
// UnZipClass UnZc=new UnZipClass();
// UnZc.UnZip(FileProperties);
string dir = System.IO.Path.GetDirectoryName(fullName);
string fileName = System.IO.Path.GetFileName(fullName);
UnZipClass.UnZipFile(fileName, dir);
}
#endregion
}
}

　　OK! 試試看。

　　此方案解決了檔案名稱中文字的問題，目錄解壓縮問題。
　　至於整個檔案夾批量上傳並壓縮成一個WINZIP壓縮包的問題，沒有時間解決了，各位如有解決方案，不妨共用一下。