【.NET】利用SharpZipLib压缩与解压文件夹中的所有文件、内存中动态压缩解压数据、内存中压缩与解压文本

SharpZipLib是一个非常优秀的.NET环境下的ZIP文档压缩与解压组件，免费且开源。

本篇文章介绍一下如何使用该组件压缩一个文件夹中的所有文件到ZIP文档、解压一个ZIP文档到文件夹，以及如何利用SharpZipLib在内存中动态的加解压数据。

下载最新版的SharpZipLib http://www.icsharpcode.net/OpenSource/SharpZipLib/Download.aspx

Imports System.IOImports System.TextImports ICSharpCodeImports ICSharpCode.SharpZipLibImports ICSharpCode.SharpZipLib.ZipImports ICSharpCode.SharpZipLib.Zip.CompressionImports ICSharpCode.SharpZipLib.CorePublic Class iZip    ''' <summary>加压数据</summary>    ''' <param name="data">数据</param>    ''' <param name="offset">起始偏移</param>    ''' <param name="length">长度</param>    ''' <param name="level">压缩级别</param>    Public Shared Function Compress(ByVal data As Byte(), Optional ByVal offset As Integer = 0, Optional ByVal length As Integer = -1, Optional ByVal level As Integer = 9) As Byte()        If data Is Nothing OrElse data.Length = 0 Then Return Nothing        If offset < 0 Then offset = 0        If length < 0 Then length = data.Length        If level < 0 Then level = 1        If level > 9 Then level = 9        Dim ms As New MemoryStream        Dim def As New Deflater        def.SetLevel(level)        def.SetInput(data, offset, length)        Dim output(&H400 - 1) As Byte        Do Until def.IsFinished            Dim count As Integer = def.Deflate(output)            ms.Write(output, 0, count)        Loop        Dim ret As Byte() = ms.ToArray        ms.Close()        Return ret    End Function    ''' <summary>加压字符</summary>    ''' <param name="str">字符</param>    ''' <param name="enc">编码</param>    ''' <param name="level">压缩级别</param>    Public Shared Function CompressString(ByVal str As String, Optional ByVal enc As Encoding = Nothing, Optional ByVal level As Integer = 9) As Byte()        If enc Is Nothing Then enc = Encoding.Default        Dim data As Byte() = enc.GetBytes(str)        Return Compress(data, , , level)    End Function    ''' <summary>解压数据</summary>    ''' <param name="data">数据</param>    Public Shared Function Decompress(ByVal data As Byte()) As Byte()        If data Is Nothing OrElse data.Length < 1 Then Return Nothing        Dim ms As New MemoryStream        Dim inf As New Inflater        inf.SetInput(data)        Dim buffer(&H400 - 1) As Byte        Do Until inf.IsFinished            Dim count As Integer = inf.Inflate(buffer)            ms.Write(buffer, 0, count)        Loop        Dim ret As Byte() = ms.ToArray        ms.Close()        Return ret    End Function    ''' <summary>解压字符</summary>    ''' <param name="data">数据</param>    ''' <param name="enc">编码</param>    Public Shared Function DecompressString(ByVal data As Byte(), Optional ByVal enc As Encoding = Nothing) As String        If enc Is Nothing Then enc = Encoding.Default        Dim bs As Byte() = Decompress(data)        Return enc.GetString(bs)    End Function    ''' <summary>快速加压</summary>    Public Shared Sub FastCreateZip(ByVal zipPath As String, ByVal folderPath As String, Optional ByVal fileFilter As String = "", Optional ByVal password As String = Nothing)        Dim fz As New FastZip        If password <> Nothing Then fz.Password = password        fz.CreateZip(zipPath, folderPath, True, fileFilter)    End Sub    ''' <summary>快速解压</summary>    Public Shared Sub FastExtractZip(ByVal zipPath As String, ByVal folderPath As String, Optional ByVal fileFilter As String = "", Optional ByVal password As String = Nothing)        Dim fz As New FastZip        If password <> Nothing Then fz.Password = password        fz.ExtractZip(zipPath, folderPath, fileFilter)    End Sub    ''' <summary>解压ZIP文件到目录</summary>    ''' <param name="zipPath">ZIP文件路径</param>    ''' <param name="folderPath">目标文件夹</param>    ''' <param name="password">密码</param>    ''' <param name="overwrite">是否覆盖文件</param>    Public Shared Sub DecompressZip(ByVal zipPath As String, ByVal folderPath As String, Optional ByVal password As String = Nothing, Optional ByVal overwrite As Boolean = True)        ' 初始化文档、密码、目标文件夹路径        Dim z As New ZipInputStream(File.OpenRead(zipPath))        If password <> Nothing Then z.Password = password        If folderPath = Nothing Then            'folderPath = HttpContext.Current.Server.MapPath("~/")            folderPath = Application.StartupPath        End If        If Not folderPath.EndsWith("\") Then folderPath &= "\"        If Not Directory.Exists(folderPath) Then Directory.CreateDirectory(folderPath)        Dim t As ZipEntry        Dim fp As String        ' 开始循环解压        Do            t = z.GetNextEntry            If t Is Nothing Then Exit Do            fp = folderPath & t.Name            ' 如果是文件夹则创建文件夹            If t.IsDirectory AndAlso Not Directory.Exists(fp) Then                Directory.CreateDirectory(fp)            ElseIf t.IsFile Then                ' 如果是文件则解压文件                If (Not File.Exists(fp)) OrElse (File.Exists(fp) And overwrite) Then                    Dim sw As FileStream = File.Create(fp)                    Dim size As Integer                    Dim data(2048) As Byte                    Do '循环读取数据                        size = z.Read(data, 0, data.Length)                        If size = 0 Then Exit Do                        sw.Write(data, 0, size)                    Loop                    sw.Close()                    File.SetLastWriteTime(fp, t.DateTime) '更新创建日期                End If            End If        Loop        z.Close()    End Sub    ''' <summary>压缩某个目录内全部文档到ZIP</summary>    ''' <param name="zipPath">ZIP路径</param>    ''' <param name="folderPath">目标目录</param>    ''' <param name="level">压缩级别</param>    ''' <param name="password">密码</param>    Public Shared Sub CompressFile(ByVal zipPath As String, ByVal folderPath As String, Optional ByVal level As Integer = 9, Optional ByVal password As String = Nothing)        If Not Directory.Exists(folderPath) Then Return        If folderPath.EndsWith("\") Then folderPath &= "\"        Dim z As New ZipOutputStream(File.Create(zipPath))        z.SetLevel(level)        If password <> Nothing Then z.Password = password        Dim fn As String, buffer(4096) As Byte        Dim di As Integer = folderPath.Length + 1        ' 先将主目录下所有文件加入文档        For Each f As String In Directory.GetFiles(folderPath, "*", SearchOption.TopDirectoryOnly)            fn = f.Remove(0, di)            z.PutNextEntry(New ZipEntry(fn))            ' 将文件数据写入ZIP            Using fs As FileStream = File.OpenRead(f)                StreamUtils.Copy(fs, z, buffer)            End Using        Next        ' 枚举所有文件夹        For Each d As String In Directory.GetDirectories(folderPath, "*", SearchOption.AllDirectories)            fn = d.Remove(0, di) & "\"            z.PutNextEntry(New ZipEntry(fn))            ' 枚举所有文件            For Each f As String In Directory.GetFiles(d, "*", SearchOption.TopDirectoryOnly)                fn = f.Remove(0, di)                z.PutNextEntry(New ZipEntry(fn))                Using fs As FileStream = File.OpenRead(f)                    StreamUtils.Copy(fs, z, buffer)                End Using            Next        Next        z.Close()    End SubEnd Class

其中数据动态加解压的代码分析来自Lucene.NET，其他的是参考网络上部分文章（来源不可考）。

我稍微封装了一下SharpZipLib的方法，可以更实用更方便一些。

实际上SharpZipLib有一个FastZip类，也很方便，但效率就稍微比自己写的方法低了一点。

代码未严格测试，有BUG或建议请指正。