Exchange Web Service – “You must load or assign this property before you can read its value” error message when trying to read message property

user_7742512 0
Viewed 2486

I have a mailbox that receives an automated email every 5 mins from a remote station. contained within that email is a string that needs to be compared with the same string from the previous email.

I am trying to automate this process for obvious reasons.

So far i am able to read the ConversationTopic of the emails, however, i can't seem to figure out how to read the content of the emails.

when it call this: 

email.Load();
MessageBox.Show(email.TextBody.Text.ToString());

i get the following error:

You must load or assign this property before you can read its value

I have had a google and i can't find anything that relates to my instance, so any help would be great.

This is my full code so far: 

private void Form1_Load(object sender, EventArgs e)
{
    try
    {
        //MessageBox.Show("Registering Exchange connection");

        _service = new ExchangeService
        {
            Credentials = new WebCredentials("myaddy@domain.com", "*****")
        };
    }
    catch
    {
        MessageBox.Show("new ExchangeService failed.");
        return;
    }

    // This is the office365 webservice URL
    _service.Url = new Uri("https://outlook.office365.com/EWS/Exchange.asmx");

    // Prepare seperate class for writing email to the database
    try
    {
        //MessageBox.Show("Reading mail");

        // Read 100 mails
        foreach (EmailMessage email in _service.FindItems(WellKnownFolderName.Inbox, new ItemView(10)))
        {
            if (email.ConversationTopic.ToString().Contains("from RockBLOCK 300234066454740"))
            {
                email.Load();
                MessageBox.Show(email.TextBody.Text.ToString());
            }
        }

        MessageBox.Show("Exiting");
    }
    catch (Exception ex)
    {
        MessageBox.Show("An error has occured. \n:" + ex.Message);
    }
}
exchangewebservices c#
1 Answers

The exception is thrown because you're trying to read the property Item.TextBody. This property is not a first-class email property.

The docs say:

Not all important email properties and elements are first-class properties and elements. To get the other properties or elements, you need to add them to your PropertySet if you're using the EWS Managed API, or use a property path to add them to your EWS operation call. For example, to retrieve the text body ... , create your PropertySet ...

In your case:

email.Load(new PropertySet(EmailMessageSchema.ConversationTopic, ItemSchema.TextBody));

Using this request EWS will laod and return an EmailMessage with the two properties from the PropertySet.

NOTE:
By specifying a PropertySet with the properties you need to work with, EWS may process your request faster since it has not to search for all first-class-email properties. Moreover you will not run in such an error, where you're trying to read a property, which isn't a member of the first-class-email properties.

user_28382890
Related