Monotouch: how do I get addressability to this method?

I have two methods in different .cs files. When trying to access DisplayReport (which lives in file #1) from file #2, I am getting the following error:

Error CS0120: An object reference is required to access non-static member `Prager.AppDelegate.DisplayReport()'

This code is in file #1:

    public partial class AppDelegate 
{
    public static string html;  
    public void DisplayReport()  {
        if(selectedSiteID == null)  {
            errorAlert ea = new errorAlert();

In file #2, I have this code:

    private void SendViaEmail()  {

        byte[] d开发者_如何学编程ata = File.ReadAllBytes(filePath);
        NSData datas = NSData.FromArray(data);

        string[] receipients = {txtEmailAddress.Text}; 

        if (MFMailComposeViewController.CanSendMail) {

            _mail = new MFMailComposeViewController();
            if(html != null)
                _mail.SetMessageBody(html,true);  //  indicate the body is html
            else  {
                AppDelegate.DisplayReport();    //  <--error here
            }

Your DisplayReport method needs to be static to be accessed that way:

public static void DisplayReport() {}