How to extract files from zip file

Hello

Can I extract files from a zip file I have

Thanks

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How to extract files from zip file

Pierre Leclerc
CAB - no thats different again. The GZip stream will only extract/compress GZip files AFAIK, CAB files are different (Cabinet files) which you need some other tool to do
Marc DESJARDINS

Spotty,

Your VB pointer program is in some older version of basic,

and (if I scan read the specs correctly,) only goes in one direction,

extract, not compact.

There is a guy named Elmue who has some DLLs that will let you

go in both directions (I believe he is German, but his English is excellent.)

His DLL programs (for CAB files) are at http://www.codeproject.com/cs/files/CABCompressExtract.asp

His web page (with lots of other downloads) is at http://www.netcult.ch/elmue/ElmueSoft-en.htm

The CAB Dll is in several versions C++ and DotNet; and he send me a version

compiled in Visual Studio 8.

When my test program tryed to use it, it could 'see' the DLL because I had some

intellisense that was from the DLL; However, the thing errored for 'file not found',

which I am sure was not about my cab file but about a DLL dependancy.

(The DLL uses the system cabinet.dll.)

Elmue, tryed to help me a little, but gave up when he found out I was at the level

of not understanding stack traces and other advanced debugging techniques.

(Also Elmue is a C dude, not a VB dude from what I can tell.)

Anyway, I sure wish you or NoBugz could help me out with this offline.

I really need to be able to work with cab files, but the project is not urgent.

Thanks
Gooseman1977
OK, can I extract files from CAP file
DPMevents
I want to extract from CAB files.

Can I do that in VB2005

Thanks
Steve Huckett
you cant really I believe. it may well require some 3rd party tool or "shelling" out to expand cab files
Ariel S
Check this thread...
R.Tutus

take a look at this:

http://forums.microsoft.com/MSDN/ShowPost.aspx PostID=891101&SiteID=1
Boris Zakharin

The is a Microsoft example that uses the java libraries to handle the zip files. http://msdn.microsoft.com/msdnmag/issues/03/06/ZipCompression/default.aspx

I have been trying to convert the code to VB. I keep get an invalid cast exception on the following line. Any help would be greatly appreceated.

'Reset to first object in collection. Here is where I get the invalid cast exception

m_Wrapped = m_Method

change m_Method to m_Method.invoke and this code will work.

Here is the main form

Imports System

Imports System.Collections

'Imports java.util

Imports java.util.zip

'Imports CsZip

Imports System.Collections.Specialized

Imports System.IO

Imports System.ComponentModel

Imports System.Reflection

Public Class Form1

Private m_CurrentFile As java.util.zip.ZipFile

Public Property CurrentFile() As ZipFile

Get

Return m_CurrentFile

End Get

Set(ByVal value As ZipFile)

Try

m_CurrentFile.close()

Catch ex As Exception

End Try

m_CurrentFile = value

If m_CurrentFile.ToString <> "" Then

DisplayEntries()

Text = m_CurrentFile.getName

End If

End Set

End Property

Private Sub DisplayEntries()

zipListView.BeginUpdate()

zipImageList.Images.Clear()

zipListView.Items.Clear()

Dim imgs As New ListDictionary

Dim entry As ZipEntry

For Each entry In New CsZip.EnumerationAdapter(New CsZip.EnumerationMethod(AddressOf CurrentFile.entries))

If Not entry.isDirectory Then

'Try

Dim name As String = entry.getName

Dim item As New ListViewItem(Path.GetFileName(name))

item.SubItems.Add(entry.getSize.ToString)

item.SubItems.Add(entry.getCompressedSize.ToString)

item.SubItems.Add(Path.GetDirectoryName(name))

item.Tag = entry

Dim ext As String = Path.GetExtension(name)

If imgs(ext) = Nothing Then

Dim ic As Icon = IconFromFileType(name)

If ic.ToString <> "" Then

zipImageList.Images.Add(ic)

imgs(ext) = zipImageList.Images.Count - 1

End If

If imgs(ext).ToString <> "" Then

item.ImageIndex = imgs(ext)

End If

zipListView.Items.Add(item)

End If

'Catch ex As Exception

'End Try

End If

Next

zipListView.EndUpdate()

End Sub

The class that does the zip file handleing

Imports System

Imports System.Collections

Imports java.util

Imports java.util.zip

Imports System.Collections.Specialized

Namespace frmZip

Public Delegate Function EnumerationMethod() As Enumeration

Public Class EnumerationAdapter

Implements IEnumerable

Private m_Method As EnumerationMethod

Public Class EnumerationWrapper

Implements IEnumerator

Private m_Method As EnumerationMethod

Private m_Wrapped As Enumeration

Private m_Current As Object

Public Sub New(ByRef method As EnumerationMethod)

m_Method = method

End Sub

Public ReadOnly Property Current() As Object Implements System.Collections.IEnumerator.Current

Get

Return m_Current

End Get

End Property

Public Sub Reset() Implements System.Collections.IEnumerator.Reset

' Reset to first object in collection.

If m_Method Is Nothing Then Throw New InvalidOperationException

Try

'Reset to first object in collection. Here is where I get the invalid cast exception

m_Wrapped = m_Method

If m_Wrapped Is Nothing Then Throw New InvalidOperationException

Catch ex As Exception

MessageBox.Show(ex.Message.ToString)

End Try

End Sub

Public Function MoveNext() As Boolean Implements System.Collections.IEnumerator.MoveNext

If m_Wrapped Is Nothing Then Reset()

Dim Result As Boolean = m_Wrapped.hasMoreElements

If Result Then m_Current = m_Wrapped.nextElement

Return Result

End Function

End Class

Public Sub New(ByRef method As EnumerationMethod)

If method Is Nothing Then Throw New ArgumentException

m_Method = method

End Sub

Public Function GetEnumerator() As System.Collections.IEnumerator Implements System.Collections.IEnumerable.GetEnumerator

Return New EnumerationWrapper(m_Method)

End Function

End Class

Public Delegate Function FilterEntryMethod(ByRef e As ZipEntry) As Boolean

Public Class ZipUtils

Public Shared Sub CopyStream(ByVal from As java.io.InputStream, ByVal [to] As java.io.OutputStream)

Dim buffer(8192) As SByte

buffer(8192) = New SByte

Dim got As Integer

While (got = from.read(buffer, 0, buffer.Length)) > 0

[to].write(buffer, 0, got)

End While

End Sub

Public Shared Sub ExtractZipFile(ByVal file As ZipFile, ByVal path As String, ByVal filter As FilterEntryMethod)

Dim entry As ZipEntry

For Each entry In New EnumerationAdapter(New EnumerationMethod(AddressOf file.entries))

If Not entry.isDirectory() Then

If filter Is Nothing Or filter(entry) Then

Dim s As java.io.InputStream = file.getInputStream(entry)

Try

Dim fname As String = System.IO.Path.GetFileName(entry.getName())

Dim newpath As String = System.IO.Path.Combine(path, System.IO.Path.GetDirectoryName(entry.getName()))

System.IO.Directory.CreateDirectory(newpath)

Dim dest As New java.io.FileOutputStream(System.IO.Path.Combine(newpath, fname))

Try

CopyStream(s, dest)

Finally

dest.close()

End Try

Finally

s.close()

End Try

End If

End If

Next entry

End Sub

Public Shared Function CreateEmptyZipFile(ByRef fileName As String) As ZipFile

Dim zosSPDownload As ZipOutputStream = New ZipOutputStream(New java.io.FileOutputStream(fileName))

zosSPDownload.close()

Return New ZipFile(fileName)

End Function

Public Shared Function UpdateZipFile(ByRef file As ZipFile, ByRef filter As FilterEntryMethod, ByRef newFiles() As String) As ZipFile

Dim prev As String = file.getName()

Dim tmp As String = System.IO.Path.GetTempFileName()

Dim [to] As New ZipOutputStream(New java.io.FileOutputStream(tmp))

Try

CopyEntries(file, [to], filter)

' add entries here

If Not (newFiles Is Nothing) Then

Dim f As String

For Each f In newFiles

Dim z As New ZipEntry(f.Remove(0, System.IO.Path.GetPathRoot(f).Length))

z.setMethod(ZipEntry.DEFLATED)

[to].putNextEntry(z)

Try

Dim s As New java.io.FileInputStream(f)

Try

CopyStream(s, [to])

Finally

s.close()

End Try

Finally

[to].closeEntry()

End Try

Next f

End If

Finally

[to].close()

End Try

file.close()

' now replace the old file with the new one

System.IO.File.Copy(tmp, prev, True)

System.IO.File.Delete(tmp)

Return New ZipFile(prev)

End Function

Public Overloads Shared Sub CopyEntries(ByRef from As ZipFile, ByRef [to] As ZipOutputStream)

CopyEntries(from, [to], Nothing)

End Sub

Public Overloads Shared Sub CopyEntries(ByRef from As ZipFile, ByRef [to] As ZipOutputStream, ByRef filter As FilterEntryMethod)

Dim entry As ZipEntry

Try

For Each entry In New EnumerationAdapter(New EnumerationMethod(AddressOf from.entries))

If filter Is Nothing Or filter(entry) Then

Dim s As java.io.InputStream = from.getInputStream(entry)

Try

[to].putNextEntry(entry)

Try

CopyStream(s, [to])

Finally

[to].closeEntry()

End Try

Finally

s.close()

End Try

End If

Next entry

Catch ex As Exception

MessageBox.Show(ex.Message.ToString)

End Try

End Sub

End Class

End Namespace
Aaron Silverwatch
not entirely. you may need to use 3rd party zip software like pkzip to execute it in a process and give it the right commands to extract the files or maybe some Win32 P/Invoke if the OS is Windows ME or higher as it has zip built in. The .NET Framework 2.0 has a Compression namespace but that is for GZip which is a different zip format I believe
Mirricle
The following may provide some clues to extracting cab files.

http://www.thescarms.com/vbasic/CabExplorer.asp

3rd party components are a great option which gives you the functionality in a very easy to use form and there are numerous components

http://www.programurl.com/software/compression-vb-net.htm

Some are free and support cab files - so these might be something you would want to explore.
GoDaddy
OK

How can I do it from gzip file
How to extract files from zip file

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