iOS first day

First day (Hello World)

1>uiview
All controls inherit UIView, inverted position, width, and height. UIButton uilable

2>uiviewcontroller
. h is the declaration of properties and methods (properties and methods that are open to the outside)
. M is done to achieve

Ibaction & Iboutlet
Ib:interface Builder Interface Setup

1>ibaction (essentially a void)
If you need to listen to the button click Method, you can use Ibaction,
will be able to connect with IB (View Controller), when the button is clicked, the corresponding method will be executed.

1>iboutlet socket
If you need to get/modify controls on the interface, you can use Iboutlet to connect with IB (View Controller)

Turn off the keyboard (resign resign)
[Self.num1 Resignfirstresponder]
Simple notation (regardless of who is the first responder, whether forcibly closed)
[Self.view Endediting:yes]

Frame: Position & size
Bounds: Only Size
Center: Only Location

iOS first day