Frame and START process

1. The difference between frame and bounds:

Frame is calculated from the upper left corner of the screen, and bounds is calculated from the upper left corner of the view as (0,0) from the new add

Bounds is the reference system, so the point in the upper left is the origin.

Center coordinates Reference parent view coordinate system

2. iOS boot process:

Start with the Main method:

Nsstringfromclass ([Appdelegate class]): Specifies the functionality to execute the implementation in a class that goes to Appdelegate

function of the Uiapplicationmain () method: Create an application's UIApplication object---Create a reference broker instance---establish an event loop and constantly detect the running state of the program (touch shaking)

int Main (intChar * argv[]) {    @autoreleasepool {        return  Class]));}    }

The process of iOS execution:

Start the program--the front desk--will end--into the backstage--will be entering the front desk

is a dead loop that requires a forced end program

Frame and START process