Cocoa & Objective-C is the base of Mac Os X.
Objective-C Language is an extensive to C and makes C OO(Object Oriented).
ObjectiveC Quick Learning:
http://www.raywenderlich.com/tutorials ( very cool one)
How to generate certificat signing request ( I like their QA part, include a lot of basic points you will need to start your ios development):
The developer video site:
Delegate is sth like callback function or notify mechanism. When some events happens, we call the corresponding method defined in the delegate class. As to application delegate, the delegate object specified in the UIApplicationMain is responsible to respond to the event which will affect the whole application. For example, when the application is about to run out of memory, the method ‘didReceiveMemoryWarning’ is invoked, and this is defined by an ObjectiveC protocal——UIApplicationDelegate. This protocal defines when and which delegate method should be invoked. For an application delegate class, it should declare in its .h file that it will implement a certain protocal , and then implement all the method which was not taged with ‘optional’ in the protocal.
There are a lot of other delegate protocal defined in the iPhone. If we want to implement some delegate class to handle certain events generated from a text field in the UI, we can choose UITextFieldDelegate protocal. This protocal defines the methods which will be invoked by the events which are generated by a text, like content changed.
The last thing we need to do is to assign the delegate class of a certain control or view with the delegate class we just implemented.
Some useful links:
iPhone Camera Focussing:
OpencvFrameWork for iOS:
UIColor CheatSheet: ~~~ I love this one 🙂
The Coordinates of CGRectMake