Q: Newbee question, regarding a couple of syntaxes in c#

[Visual Systems AB \(Martin Arvidsson\)]

Hi!

I was testing an application that is writing a mail and sends it to a
recieptiens. I then came across
a couple of ??? in my head, coul anyone briefly tell me what the difference
is between this and where in the help i can read more about it

First out...

Outlook.Application oApp = new Outlook.Application();
My guess is that this create a new object oApp from this
Outlook.Application? Right?

Then the following, i just don't get, what they do and what it is called...

Outlook.NameSpace oNS = oApp.GetNamespace("mapi");
(Why not xxx = new xxx)

Outlook.MailItem oMsg =
(Outlook.MailItem)oApp.CreateItem(Outlook.OlItemType.olMailItem);

Outlook.Recipients oRecips = (Outlook.Recipients)oMsg.Recipients;

Thanx in advance for any help

Regards

Martin Arvidsson

 

[Peter Jausovec]

Hi,

Outlook.NameSpace oNS = oApp.GetNamespace("mapi");
(Why not xxx = new xxx)

Outlook.MailItem oMsg =
(Outlook.MailItem)oApp.CreateItem(Outlook.OlItemType.olMailItem);

Outlook.Recipients oRecips = (Outlook.Recipients)oMsg.Recipients;

You don't need to create new namespace (therefore there is no xxx = new xxx
), but you get the namespace from the outlook application object you
created. Same goes with MailItem -> you call method CreateItem with
parameter which descibes the item you are creating (olMailItem) and because
CreateItem returns object you have to cast that to Outlook.MailItem.

Hope this helps..

 

[Anders Norås]

Outlook.Application oApp = new Outlook.Application();

My guess is that this create a new object oApp from this
Outlook.Application? Right?
Yes!

Then the following, i just don't get, what they do and what it is
called...

Outlook.NameSpace oNS = oApp.GetNamespace("mapi");
(Why not xxx = new xxx)

GetNamespace is a factory method. A factory is a method that creates an
object instance for you based on parameters or other stimuli.
On the inside the GetNamespace method could do something like this:
public NameSpace GetNamespace(string ns) {
if (ns=="mapi") return new MapiNamespace();
else return new OtherNamespace();
}

Outlook.MailItem oMsg =
(Outlook.MailItem)oApp.CreateItem(Outlook.OlItemType.olMailItem);

The CreateItem is another factory method. This method creates the item type
you ask for, in your example an olMailItem. Because the return type of the
factory is a base class you have to cast it to the more specific type
MailItem.

Outlook.Recipients oRecips = (Outlook.Recipients)oMsg.Recipients;

Same as above. The Recipients property is casted to a Recipients type.

Anders Norås
blog: http://dotnetjunkies.com/weblog/anoras