How to get single file from zip file? - vb.net

Question

I want to get just one file from .zip file in VB.NET. I don't need to extract all of .zip file, just one file.
I'm working with framework 4.5.

Answer 1

.NET Framework 4.5 has ZipFile class which can do this for you. This code should get you started:
Dim zipPath As String = "Sample.zip"
Using archive = ZipFile.Open(zipPath, ZipArchiveMode.Read)
Dim entry = archive.GetEntry("MyFile.pdf")
Using reader As New BinaryReader(entry.Open())
System.IO.File.WriteAllBytes("MyFile.pdf", ReadAllBytes(reader))
End Using
End Using
ReadAllBytes() is a helper method that fetches all bytes from a binary stream:
Public Shared Function ReadAllBytes(reader As BinaryReader) As Byte()
Const bufferSize As Integer = 4096
Using ms As New MemoryStream()
Dim buffer(bufferSize) As Byte
Dim count As Integer
Do
count = reader.Read(buffer, 0, buffer.Length)
If count > 0 Then ms.Write(buffer, 0, count)
Loop While count <> 0
Return ms.ToArray()
End Using
End Function
Make sure you're using .NET Framework 4.5 or above and that you have included references to System.IO.Compression and System.IO.Compression.FileSystem.

Answer 2

try with this code with the help of DotNetZip
Using zip As ZipFile = ZipFile.Read(ExistingZipFile)
Dim e As ZipEntry = zip("DocumentToFind.txt")
e.Extract(OutputStream)
End Using
otherwise you can use ZipArchiveClass in this way
Using zip As ZipArchive = ZipFile.Open(zipfile, ZipArchiveMode.Read)
Dim file = zip.Entries.Where(Function(x) x.Name = "fileToFind")
If file IsNot Nothing Then
file.ExtractToFile("yourFile")
End If
End Using

Answer 3

This will allow you to read txt files from a zip line by line
Dim zipPath As String = "ZIP FILE LOCATION"
Using zipStream = New FileStream(last_pafx23_open, FileMode.Open)
Using archive = New ZipArchive(zipStream, ZipArchiveMode.Read)
For Each ent In archive.Entries
MsgBox(ent.ToString)
Using stream = ent.Open()
Using reader = New StreamReader(stream)
While Not reader.EndOfStream
MsgBox(reader.ReadLine)
End While
End Using
End Using
Next
End Using
End Using

Answer 4

Skip the BinaryReader w/ ReadAllBytes() helper function, use ExtractToFile() instead:
Imports System.IO.Compression
Using archive = ZipFile.Open("Sample.zip", ZipArchiveMode.Read)
Dim entry = archive.GetEntry("MyFile.pdf")
If entry IsNot Nothing then entry.ExtractToFile("MyFile.pdf")
End Using
Still needs the references to System.IO.Compression and System.IO.Compression.FileSystem, of course.