如何知道要导入什么？

Question

I have always been confused in finding out what i need to import in order to use a feature.

For example, when i use MFMailComposeViewController I know from googling that i need to

#import <MessageUI/MFMailComposeViewController.h>

and add: MessageUI.framework

From the reference documentation, how do I know that i need these things?

http://developer.apple.com/library/ios/#documentation/MessageUI/Reference/MFMailComposeViewController_class/Reference/Reference.html

I want to learn how to better use the reference docs without relying on googling sample codes to find out what i need to import in the future, so can someone explain how to figure this out from documentation?

Answer 1

See how at the top it says it's declared in MFMailComposeViewController.h? The question then is what framework that's in. Here's one way to find out.

Start in an actual iOS project in Xcode. Press Shift-Command-O (File > Open Quickly) and paste or type MFMailComposeViewController into it. Open the listing for MFMailComposeViewController.h.

Now read the jump bar at the top of the editor. It says: ... > Frameworks > MessageUI.framework > ...

This lets you deduce that you need the MessageUI framework and that you need to import (not what you said, but) <MessageUI/MessageUI.h> .

Answer 2

This is how I do it and it might be useful to you too..

Have you notice the navigation bar on the top? if you click "MFMailComposeViewController class Reference" field then it will give you something like this..

then you can see the "Message UI Framework Reference" and this page tells you exactly what you need to import.. this is not perfect but it helps most of time...