如何添加事件处理程序以在 Outlook 中阅读或打开任何邮件？ VSTO

Question

The idea of my plugin is that when I click (read) or double click (open) on any email in my Outlook explorer inbox, a windows form is displayed. I understand that I must put the event handler in the ThisAddIn_Startup method to make it work while Outlook is open. I have tried the following:

Outlook.MailItem mailItem = new Outlook.MailItem();
mailItem.Open += new Microsoft.Office.Interop.Outlook.ItemEvents_10_OpenEventHandler(ClickSobreCorreo);
mailItem.Read += new Microsoft.Office.Interop.Outlook.ItemEvents_10_ReadEventHandler(ClickSobreCorreo);
    
Outlook.AppointmentItem Cita = new Outlook.AppointmentItem();
Cita.Open += new Microsoft.Office.Interop.Outlook.ItemEvents_10_OpenEventHandler(ClickSobreCorreo);
Cita.Read += new Microsoft.Office.Interop.Outlook.ItemEvents_10_ReadEventHandler(ClickSobreCorreo);
    
Outlook.MeetingItem Reunion = new Outlook.MeetingItem();
Reunion.Open += new Microsoft.Office.Interop.Outlook.ItemEvents_10_OpenEventHandler(ClickSobreCorreo);
Reunion.Read += new Microsoft.Office.Interop.Outlook.ItemEvents_10_ReadEventHandler(ClickSobreCorreo);

But I get an error:

System.Runtime.InteropServices.COMException (0x80040154): Class not registered (Exception from HRESULT: 0x80040154

Then I tried this that I found on the web but only a random mail works (it is not even the first mail) and the read event only executes once and no more.

    Outlook.MailItem mailItem;

    private void ThisApplication_Startup (object sender, EventArgs e) {
        Outlook.NameSpace ns = this.Session;
        Outlook.MAPIFolder inbox =
            ns.GetDefaultFolder (
                Outlook.OlDefaultFolders.olFolderInbox);

        foreach (object o in inbox.Items) {
            mailItem = o as Outlook.MailItem;
            if (mailItem != null) {
                break;
            }
        }

        if (mailItem == null) {
            MessageBox.Show ("Couldn't find a mail item to connect to.");
        } else {
            MessageBox.Show (String.Format (
                    "Connected to the mail item with subject {0}.",
                    mailItem.Subject);

                mailItem.Read += new Outlook.ItemEvents_10_ReadEventHandler (
                    MailItem_Read);

                mailItem.Open += new Outlook.ItemEvents_10_OpenEventHandler (
                    MailItem_Open);

                mailItem.Write += new Outlook.ItemEvents_10_WriteEventHandler (
                    MailItem_Write);

                ((Outlook.ItemEvents_10_Event) mailItem).Close += new Outlook.ItemEvents_10_CloseEventHandler (
                    MailItem_Close);
            }
        }
    }

    void MailItem_Read() {
        MessageBox.Show("Read");
    }

    void MailItem_Open(ref bool cancel) {
        MessageBox.Show("Open");
    }

    void MailItem_Write(ref bool cancel) {
        MessageBox.Show("Write");
    }

    void MailItem_Close(ref bool cancel) {
        MessageBox.Show("Close");
    }

What should I do? Do I have to go through all the emails and assign the event handler to them? If so, how would you do with the incoming emails, should I add an event handler for the incoming emails and in the method add the event handler to open and read the email?

Answer 1

Do not use " new " with Outlook.MailItem - that object is not creatable, Outlook.Application is, but you get an instance of that object (the trusted version) from Outlook anyway.

What I suspect you need to to track the Exploer.SelectionChange event ( Explorer can be received from Applica5tion.ActiveExplorer and Application.Explorers.NewExplorer ) and set up event handlers on the selected items (Explorer.Selection).

Make sure to keep the objects raising the events ( Explorer and Explorers ) referenced so they are not garbage collected.