ios - Change view in a page view controller when button is pressed in one of the controllers -

i have uipageviewcontroller connected 3 view controllers

and 3 classes each uiviewcontroller

when "take photo" button pushed, third view should slide view. when "choose library" pushed first view controller should slide view.

i have 3 classes controlling each uiviewcontroller , 1 class controls pages in storyboard. here pageviewcontroller.m

@implementation pageviewcontroller  { nsarray *myviewcontrollers; }  - (void)viewdidload {   [super viewdidload];        self.delegate = self;   self.datasource = self;    uiviewcontroller *p1 = [self.storyboard instantiateviewcontrollerwithidentifier:@"one"];   uiviewcontroller *p2 = [self.storyboard instantiateviewcontrollerwithidentifier:@"two"];   uiviewcontroller *p3 = [self.storyboard instantiateviewcontrollerwithidentifier:@"three"];     myviewcontrollers = @[p1, p2, p3];   pagetwoviewcontroller *ptvc = [[pagetwoviewcontroller alloc] init];   ptvc.publicviewcontrollers = myviewcontrollers;    [self setviewcontrollers:@[p2] direction:uipageviewcontrollernavigationdirectionforward animated:no completion:nil]; 

the app has been programmed switch views when flicking left or right.

i have buttons linked respecting classes don't know how switch visible view controllers via buttons. how can change visible uiviewcontroller when 1 of buttons pushed on second view controller?

call "setviewcontrollers" again switch different view controller. so, example, if wanted move "p1", use this:

// grab reference out of existing nsarray uiviewcontroller *newvc = self.myviewcontrollers[0]; [self setviewcontrollers:@[newvc] direction:uipageviewcontrollernavigationdirectionreverse animated:yes completion:nil]; 

using "animated:yes" cause same slide if user navigated manually. adjust "direction" based on whether jumping forward or backwards.

to communicate between child view controllers , parent, use delegate. first, declare delegate in parent view controller's header, such this:

@protocol photosourcedelegate <nsobject>   - (void)takephoto;   - (void)choosefromlibrary; @end 

update parent view controller implement delegate:

@interface pageviewcontroller : uipageviewcontroller <photosourcedelegate> @end  @implementation pageviewcontroller ... #pragma mark - photosourcedelegate - (void)takephoto {   // call "setviewcontroller" display "take photo" view controller; }  - (void)choosefromlibrary {   // call "setviewcontroller" display "choose library" view controller; } 

within header of view controller shows "take photo" , "choose library" buttons (p2?), add property hold reference delegate:

@property(nonatomic, weak) id<photosourcedelegate> delegate; 

when instantiate controller, sure set delegate:

uiviewcontroller *p2 = [self.storyboard instantiateviewcontrollerwithidentifier:@"two"]; p2.delegate = self; 

finally, within same view controller, when "take photo" button pressed, call delegate this:

if (self.delegate != nil) {   [self.delegate takephoto]; } 

and when "choose library" button pressed, call delegate this:

if (self.delegate != nil) {   [self.delegate choosefromlibrary]; } 

the use of delegates common in ios, quick search turn quite few tutorials if/when you're ready better understanding.