This way
protected void Upload(object sender, EventArgs e)
{
string extractPath = Server.MapPath("~/Files/");
using (ZipFile zip = ZipFile.Read(Server.MapPath("~/Files/Test.zip")))
{
zip.ExtractAll(extractPath, ExtractExistingFileAction.DoNotOverwrite);
GridView1.DataSource = zip.Entries;
GridView1.DataBind();
}
}