Two-way event response (Viewwilllayoutsubviews and notifications)

Source: Internet
Author: User

Recently the screen, get some experience, special record down.

The most important thing is to determine the interface of the screen response. There are two ways I know now:

1. Use notifications.

-(void) viewdidload

{

[[Nsnotificationcenter Defaultcenter] addobserver:self selector: @selector (_orientationdidchange:) Name: Uideviceorientationdidchangenotification Object:nil];

}

-(void) Dealloc {

[[Nsnotificationcenter Defaultcenter] removeobserver:self name:uideviceorientationdidchangenotification object:nil ]; }

-(void) _orientationdidchange: (nsnotification*) Notify

{

[Self _shouldrotatetoorientation: (uideviceorientation) [UIApplication sharedapplication].statusbarorientation];

}

-(void) _shouldrotatetoorientation: (uideviceorientation) Orientation {

if (orientation = = Uideviceorientationportrait | | Orientation = = Uideviceorientationportraitupsidedown) {

Vertical screen

}

else {

Horizontal screen

}

}

The above code, a look will understand.

2. Using Viewwilllayoutsubviews

When the test finds the screen switching, the system responds to some functions, one of which is viewwilllayoutsubviews.

-(void) viewwilllayoutsubviews

{

[Self _shouldrotatetoorientation: (uideviceorientation) [UIApplication sharedapplication].statusbarorientation];

The interface between the screen and the switch is known through one of these functions.

Attention:

Viewwilllayoutsubviews can only be used in Viewcontroller, there is no response in view.




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