C#- 'using' statement doesn't appear to be acknowledged

Question

I have the following code block in my application:

try
{
    string extractPath = @"C:\Documents";
    using (ZipArchive zip = ZipFile.Open(zipFP, ZipArchiveMode.Read))
        foreach(ZipArchiveEntry entry in zip.Entries)
        {
            try
            {
                extractedPDF = System.IO.Path.Combine(extractPath, entry.FullName);
                entry.ExtractToFile(extractedPDF, true);
            }
            catch (System.IO.IOException)
            {
                Console.WriteLine("File already exists... ");
                Console.WriteLine("Error during extraction... ");
            }
        }
    Console.WriteLine("PDF extracted from ZIP: '{0}'...", string.Concat(extractPath, zipFP));
    PdfPanel.OpenFile(extractedPDF);
}catch(AccessViolationException ex)
{
    Console.WriteLine("Can't display a zip in the PDF panel... " + ex.InnerException);
}

At the moment, I am getting a compile error on the using & foreach lines which highlights ZipArchive, ZipFile, ZipArchiveMode & ZipArchiveEntry.

The compile error says:

The type or namespace name 'ZipArchive' could not be found (are you missing a using directive or an assembly reference?

But I have a using statement for System.IO.Compression at the top of this file, and I am sure that I have added all of the references and other using statements that I need for the code... I copied this code over from a separate project that is fully functioning, and have checked that I have added all of the missing using statements and references from that project.

What else could be causing this problem? Why isn't the compiler picking up the fact that I am using the System.IO.Compression package?

Answer 1

You need to add a reference to the assembly. In the Solution Explorer, under your project right-click References -> Add Reference. Find System.IO.Compression in the list of Framework Assemblies. Check the box for it and press OK.