title: Error CS0103: The name 'ZipFile' does not exist in the current context
body: <p>i was working on .net core wpf game lancher but the error &quot;<strong>Error CS0103: The name 'ZipFile' does not exist in the current context</strong>&quot; appeared. even i used the following line: using System.IO.Compression; but it didnt work.</p>
  <pre><code>        private void DownloadGameCompletedCallback(object sender, AsyncCompletedEventArgs e)
          {
              try
              {
                  string onlineVersion = ((Version)e.UserState).ToString();
                  ZipFile.ExtractToDirectory(gameZip, rootPath, true); // error cs0103
                  File.Delete(gameZip);
  
                  File.WriteAllText(versionFile, onlineVersion);
  
                  VersionText.Text = onlineVersion;
                  Status = LauncherStatus.ready;
              }
              catch (Exception ex)
              {
                  Status = LauncherStatus.failed;
                  MessageBox.Show($&quot;Error finishing download: {ex}&quot;);
              }
          }
  </code></pre>
  <p>tried change namespace, class to GameLauncher in mainwindow.xaml (didn't work)</p>