I am using the Exchange Web Services Managed API to work with Tasks (Exchange 2007 SP1). I can create them fine. However, when I try to do updates, it works for all of the fields except for the .Body field. Whenever I try to access (read/update) that field, it gives the following error:
"You must load or assign this property before you can read its value."
The code I am using looks like this:
//impersonate the person whose tasks you want to read
Me.Impersonate(userName); //home-made function to handle impersonation
//build the search filter
Exchange.SearchFilter.SearchFilterCollection filter = New Exchange.SearchFilter.SearchFilterCollection();
filter.Add(New Exchange.SearchFilter.IsEqualTo(Exchange.TaskSchema.Categories, "Sales"));
//do the search
EWS.Task exTask = esb.FindItems(Exchange.WellKnownFolderName.Tasks, filter, New Exchange.ItemView(Integer.MaxValue));
exTask.Subject = txtSubject.Text; //this works fine
exTask.Body = txtBody.Text; //This one gives the error implying that the object isn't loaded
The strange thing is that, inspecting the property bag shows that the object contains 33 properties, but {Body} is not one of them. That property seems to be inherited from the base class .Item, or something.
So, do I need to re-load the object as type Item? Or reload it via .Bind or something? Keep in mind that I need to do this with thousands of items, so efficiency does matter to me.
Calling the Load method solved my problem :)
You can load properties using a custom property set. Some properties are Extended properties instead of FirstClassProperties.
Little example:
I had the same problem when using the EWS. My Code is requesting the events(Appointments) from the
Outlook calendar, at the end I couldn't reach to the body of the Event itself.
The missing point in my situation was the following "forgive me if there is any typo errors":
After gathering the Appointments, which are also derived from EWS Item Class, I did the following:
1- Create a List with the type Item:
2- Added all appointments to items list:
3- Used the exchanged service "I have already created and used":
now if you try to use app.Body.Text, it will return it successfully.
Enjoy Coding and Best Luck
I forgot to mention the resource:
http://social.technet.microsoft.com/Forums/en-US/exchangesvrdevelopment/thread/ce1e0527-e2db-490d-817e-83f586fb1b44
He mentioned the use of Linq to save the intermediate step, it will help you avoid using the List items and save some memory!
RockmanX