using System;
using System.ComponentModel;
using System.Windows.Forms;
namespace ElementVirtual
{
  internal class DemoLicenseProvider : LicFileLicenseProvider
  {
    public override License GetLicense(LicenseContext context, Type type, object instance, bool allowExceptions)
    {
      string text = "You are using demo version of the Example element.\n"
        + "To get full version please visit:\n\nhttp://hiasm.ddns.net/hiasm.net/license.html";
      MessageBox.Show(text, Application.ProductName, MessageBoxButtons.OK, MessageBoxIcon.Asterisk);
      return new DemoLicense("granted");
    }
  }
  internal class DemoLicense : License
  {
    private string m_LicenseKey;
    public override string LicenseKey { get { return m_LicenseKey; } }
    public DemoLicense(string license)
    {
      m_LicenseKey = license;
    }
    public override void Dispose() { }
  }
}

[LicenseProvider(typeof(DemoLicenseProvider))]
public class Example : ElementClass
{
...
}

public override void prepareForRun(ref Element parent)
{
...
  License license = LicenseManager.Validate(this.GetType(), this);
}

public class Example : ElementClass
{
  public override bool init(object entry)
  {
    Debug.WriteLine("{0}.init()".fString(this.codename));
    sys.add_use("System.ComponentModel");
    sys.add_use("ElementVirtual");
    sys.useClass("DemoLicenseProvider");
    string license = "[LicenseProvider(typeof(DemoLicenseProvider))]";
    if (!sys.blk_class_attr.astext().Contains(license))
    {
      sys.blk_class_attr.println(license);
      sys.blk_init.println("License license = LicenseManager.Validate(this.GetType(), this);");
    }
...