Using the ByteProgression and InvalidPassword events (ZipReader) Snippet

The following examples demonstrate how to use ZipReader's ByteProgression and InvalidPassword events, as well as their event arguments.

using System.IO;

using Xceed.Zip.ReaderWriter;

//The source Zip archive.

using (FileStream fileStream1 = new FileStream(@"d:\testOutput\test.zip",

  FileMode.Open, FileAccess.Read))

{

  //Must seek to the beginning of the stream before reading.

  fileStream1.Seek(0, SeekOrigin.Begin);

  //Create a ZipReader around the stream.

  Xceed.Zip.ReaderWriter.ZipReader zipReader1 =

    new Xceed.Zip.ReaderWriter.ZipReader(fileStream1);

  //Subscribe to the ByteProgression event

  zipReader1.ByteProgression +=

    new EventHandler<ZipReaderByteProgressionEventArgs>

    (zipReader1_ByteProgression);

  //Subscribe to the InvalidPassword event

  zipReader1.InvalidPassword +=

    new EventHandler<ZipReaderInvalidPasswordEventArgs>

    (zipReader1_InvalidPassword);

  ZipItemLocalHeader zipItemLocalHeader = null;

  //Read the local headers until no more are found

  while ((zipItemLocalHeader = zipReader1.ReadItemLocalHeader()) != null)

  {

    byte[] buffer = new byte[1024];

    int read = 0;

    //Read the item's data

    while ((read = zipReader1.ReadItemData(buffer, 0, buffer.Length)) > 0)

    {

      //Do something with the data in 'buffer'

    }

  }

}



//The InvalidPassword event's handler. Demonstrates the use of

//the properties of ZipReaderInvalidPasswordEventArgs.

static void zipReader1_InvalidPassword(object sender,

  ZipReaderInvalidPasswordEventArgs e)

{

  Console.Write("Enter password for file {0} (<Enter> alone to abort): ",

    e.ZipItemLocalHeader.FileName);

  string password = Console.ReadLine();

  if (string.IsNullOrEmpty(password))

  {

    //Set Abort to true to abort the read operation.

    e.Abort = true;

  }

  else

  {

    //Set NewPassword to the provided password. If it is the correct password,

    //the read operation will proceed. Otherwise, the InvalidPassword event is

    //raised again.

    e.NewPassword = password;

  }

}

//The ByteProgression event's handler. Demonstrates the use of

//the properties of ZipReaderByteProgressionEventArgs.

static void zipReader1_ByteProgression(object sender,

   ZipReaderByteProgressionEventArgs e)

{

  if (e.UncompressedSize == -1)

    Console.WriteLine("Processing item {0}: {1} bytes processed.",

      e.ZipItemLocalHeader.FileName, e.BytesProcessed);

  else

  {

    //UncompressedSize is not -1, so this property and the Percent property

    //return useful values.

    Console.WriteLine("Processing item {0}: {1} bytes processed ({3}%).

      (Uncompressed size = {3}.)",

      e.ZipItemLocalHeader.FileName,

      e.BytesProcessed,

      e.UncompressedSize,

      e.Percent);

  }

}

VB.NET

Imports System.IO

Imports Xceed.Zip.ReaderWriter

Using fileStream1 As New FileStream("d:\testOutput\test.zip",

  FileMode.Open, FileAccess.Read)



  'Must seek to the beginning of the stream before reading.

  fileStream1.Seek(0, SeekOrigin.Begin)

  'Create a ZipReader around the stream.

  Dim zipReader1 As New Xceed.Zip.ReaderWriter.ZipReader(fileStream1)

  'Subscribe to the ByteProgression event

  AddHandler zipReader1.ByteProgression, AddressOf Of

    ZipReaderByteProgressionEventArgs

  'Subscribe to the InvalidPassword event

  AddHandler zipReader1.InvalidPassword, AddressOf Of

    ZipReaderInvalidPasswordEventArgs

  Dim zipItemLocalHeader As ZipItemLocalHeader = Nothing

  'Read the local headers until no more are found

  Do While Not (zipItemLocalHeader = zipReader1.ReadItemLocalHeader()) Is

  Nothing

    Dim buffer As Byte() = New Byte(1023){}

    Dim read As Integer = 0

    'Read the item's data

    Do While (read = zipReader1.ReadItemData(buffer, 0, buffer.Length)) > 0

      'Do something with the data in 'buffer'

    Loop

  Loop

End Using



'The InvalidPassword event's handler. Demonstrates the use of

'the properties of ZipReaderInvalidPasswordEventArgs.

Shared Sub zipReader1_InvalidPassword(ByVal sender As Object, ByVal e As

  ZipReaderInvalidPasswordEventArgs)

  Console.Write("Enter password for file {0} (<Enter> alone to abort): ",

    e.ZipItemLocalHeader.FileName)

  Dim password As String = Console.ReadLine()

  'Set Abort to true to abort the read operation.

  If String.IsNullOrEmpty(password) Then

    e.Abort = True

  Else

    'Set NewPassword to the provided password. If it is the correct password,

    'the read operation will proceed. Otherwise, the InvalidPassword event is

    'raised again.

    e.NewPassword = password

  End If

End Sub



'The ByteProgression event's handler. Demonstrates the use of

'the properties of ZipReaderByteProgressionEventArgs.

Shared Sub zipReader1_ByteProgression(ByVal sender As Object, ByVal e As

  ZipReaderByteProgressionEventArgs)

  If e.UncompressedSize = -1 Then

    Console.WriteLine("Processing item {0}: {1} bytes processed.",

      e.ZipItemLocalHeader.FileName, e.BytesProcessed)

  Else

    'UncompressedSize is not -1, so this property and the Percent

    'property return useful values.

    Console.WriteLine("Processing item {0}: {1} bytes processed

      ({3}%). (Uncompressed size = {3}.)",

      e.ZipItemLocalHeader.FileName,

      e.BytesProcessed, e.UncompressedSize, e.Percent)

  End If

End Sub