ZipArchive.ItemAdding Event

Occurs before a zip item is added to the archive.

Namespace: DevExpress.Compression

Assembly: DevExpress.Docs.v24.1.dll

NuGet Package: DevExpress.Document.Processor

Declaration

C#

public event ZipItemAddingEventHandler ItemAdding

VB.NET

Public Event ItemAdding As ZipItemAddingEventHandler

Event Data

The ItemAdding event's data class is ZipItemAddingEventArgs. The following properties provide information specific to this event:

Property	Description
Action	Gets or sets the action required to perform after the ItemAdding event is handled.
Item	Obtains the zip item being added to the archive.

Remarks

By handling the ItemAdding event you can decide whether or not a certain item should be added to the archive. The item is accessible by using the ZipItemAddingEventArgs.Item property. The ZipItemAddingEventArgs.Action property allows you to skip the current item or to stop adding items to the archive.

This example demonstrates how to handle the ZipArchive.ItemAdding event to decide for each file whether it should be included in the archive.

If a file creation date is not the current date, the file is not added to the archive. A volatile variable is used to indicate whether the process should be stopped - it can be useful to interrupt archive creation if too many files are specified.

View Example

ZipExamples.cs

using DevExpress.Compression;
//...
volatile bool stopArchiving = false;

public void FilterArchiveFiles() {
    string[] sourceFiles = this.sourceFiles;
    using (ZipArchive archive = new ZipArchive()) {
        archive.ItemAdding += archive_ItemAdding;
        foreach (string file in sourceFiles) {
            archive.AddFile(file, "/");
        }
        archive.Save("FilterArchiveFiles.zip");
    }
}

private void archive_ItemAdding(object sender, ZipItemAddingEventArgs args) {
    if (args.Item.CreationTime.Date != DateTime.Today)
        args.Action = ZipItemAddingAction.Cancel;
    if (stopArchiving) args.Action = ZipItemAddingAction.Stop;
}

ZipExamples.vb

Imports DevExpress.Compression

volatile bool stopArchiving = False

Private stopArchiving As Boolean = False
Public Sub FilterArchiveFiles()
    Dim sourceFiles() As String = Me.sourceFiles
    Using archive As New ZipArchive()
        AddHandler archive.ItemAdding, AddressOf archive_ItemAdding
        For Each file As String In Me.sourceFiles
            archive.AddFile(file, "/")
        Next file
        archive.Save("Documents\FilterArchiveFiles.zip")
    End Using
End Sub

Private Sub archive_ItemAdding(ByVal sender As Object, ByVal args As ZipItemAddingEventArgs)
    If args.Item.CreationTime.Date <> DateTime.Today Then
        args.Action = ZipItemAddingAction.Cancel
    End If
    If stopArchiving Then
        args.Action = ZipItemAddingAction.Stop
    End If
End Sub

Related GitHub Examples

The following code snippet (auto-collected from DevExpress Examples) contains a reference to the ItemAdding event.

Note

The algorithm used to collect these code examples remains a work in progress. Accordingly, the links and snippets below may produce inaccurate results. If you encounter an issue with code examples below, please use the feedback form on this page to report the issue.

C#

zip-compression-and-archive-api-examples/CS/CompressionLibraryExamples/ZipExamples.cs#L76

using (ZipArchive archive = new ZipArchive()) {
    archive.ItemAdding += archive_ItemAdding;
    foreach (string file in sourceFiles) {

VB.NET

zip-compression-and-archive-api-examples/VB/CompressionLibraryExamples/ZipExamples.vb#L77

Using archive As New ZipArchive()
    AddHandler archive.ItemAdding, AddressOf archive_ItemAdding
    For Each file As String In Me.sourceFiles