Zipping some files ends in crash

Question

I'm trying to the following to zip some files, but it always ends in a crash with this exception:

A first chance exception of type 'System.ArgumentException' occurred in System.Runtime.WindowsRuntime.NI.DLL

Additional information: The specified buffer index is not within the buffer capacity.

The code:

    Private Async Sub ZipFiles()
        Dim filesToCompress As IReadOnlyList(Of Windows.Storage.StorageFile) = Await Windows.Storage.ApplicationData.Current.LocalFolder.GetFilesAsync

        Using zipMemoryStream As New MemoryStream
            Using zipArchive As Compression.ZipArchive = New Compression.ZipArchive(zipMemoryStream, Compression.ZipArchiveMode.Create)
                For Each fileToCompress As Windows.Storage.StorageFile In filesToCompress
                    ' The following line is the one that's raising the exception
                    Dim buffer As Byte() = WindowsRuntimeBufferExtensions.ToArray(Await Windows.Storage.FileIO.ReadBufferAsync(fileToCompress))
                    Dim entry As Compression.ZipArchiveEntry = zipArchive.CreateEntry(fileToCompress.Name)

                    Using entryStream As Stream = entry.Open
                        Await entryStream.WriteAsync(buffer, 0, buffer.Length)
                    End Using
                Next
            End Using

            Dim zipFile As Windows.Storage.StorageFile = Await Windows.Storage.ApplicationData.Current.LocalFolder.CreateFileAsync("MyZipfile.zip", Windows.Storage.CreationCollisionOption.ReplaceExisting)
            Using zipStream As Windows.Storage.Streams.IRandomAccessStream = Await zipFile.OpenAsync(Windows.Storage.FileAccessMode.ReadWrite)
                Using outstream As Stream = zipStream.AsStreamForWrite
                    Dim buffer() As Byte = zipMemoryStream.ToArray
                    outstream.Write(buffer, 0, buffer.Length)
                    outstream.Flush()
                End Using
            End Using
        End Using
    End Sub

Any ideas on how make this Work?

Answer 1

Hi FacilisDK,

There is not enough information for me to troubleshooting your problem. So please refer to a working sample from MSDN code gallery https://code.msdn.microsoft.com/windowsapps/How-to-and-extract-zip-a4794b24 to see if it is working in your scenario.

If not, please post a repro project here. Use your OneDrive and share a link.

Regards,

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Answer 2

Solved. The Exception was raised due to zero-length files.