PageView Controller errors 'Expected selector for Objective C' - ios

Question

I'm having so much trouble creating a pageview controller. I have made adjustments to my code three times but i KEEP getting the following error: ' Expected selector for Objective C method'. I also get another error message which says Missing '#end'. Could anyone please tell me why I recieve these messages? :l
#import "InstructionContentViewController.h"
#import "StorageViewController.h"
#interface StorageViewController ()
#end
#implementation StorageViewController
- (void)viewDidLoad
{
[super viewDidLoad];
// Create the data model
_pageTitles = #[#"Over 200 Tips and Tricks", #"Discover Hidden Features", #"Bookmark Favorite Tip", #"Free Regular Update"];
_pageImages = #[#"instructions1.png", #"instructions2.png", #"instructions3.png", #"instructions4.png"];
// Create page view controller
self.instructionViewController = [self.storyboard instantiateViewControllerWithIdentifier:#"InstructionViewController"];
self.instructionViewController.dataSource = self;
InstructionContentViewController *startInstructViewController = [self viewControllerAtIndex:0];
NSArray *viewControllers = #[startInstructViewController];
[self.instructionViewController setViewControllers:viewControllers direction:UIPageViewControllerNavigationDirectionForward animated:NO completion:nil];
// Change the size of page view controller
self.instructionViewController.view.frame = CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height - 50);
[self addChildViewController:_instructionViewController];
[self.view addSubview:_instructionViewController.view];
[self.instructionViewController didMoveToParentViewController:self];
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
- (IBAction)startWalkthrough:(id)sender {
InstructionContentViewController *startingInstructViewController = [self viewControllerAtIndex:0];
NSArray *viewControllers = #[startingInstructViewController];
[self.instructionViewController setViewControllers:viewControllers direction:UIPageViewControllerNavigationDirectionReverse animated:NO completion:nil];
}
#pragma mark - Page View Controller Data Source Methods:
- (UIViewController *)pageViewController:(UIPageViewController *)pageViewController viewControllerBeforeViewController:(UIViewController *)viewController
{
NSUInteger index = ((InstructionContentViewController*) viewController).pageIndex;
if ((index == 0) || (index == NSNotFound)) {
return nil;
}
index--;
return [self viewControllerAtIndex:index];
}
- (UIViewController *)pageViewController:(UIPageViewController *)pageViewController viewControllerAfterViewController:(UIViewController *)viewController
{
NSUInteger index = ((InstructionContentViewController*) viewController).pageIndex;
if (index == NSNotFound) {
return nil;
}
index++;
if (index == [self.pageTitles count]) {
return nil;
}
return [self viewControllerAtIndex:index];
}
- (InstructionContentViewController *)viewControllerAtIndex:(NSUInteger)index
{
if (([self.pageTitles count] == 0) || (index >= [self.pageTitles count])) {
return nil;
}
// Create a new view controller and pass suitable data.
InstructionContentViewController *instructionContentViewController = [self.storyboard instantiateViewControllerWithIdentifier:#"InstructionContentViewController"];
instructionContentViewController.instructimageFile = self.pageImages[index];
instructionContentViewController.instructtitleText = self.pageTitles[index];
instructionContentViewController.pageIndex = index;
return instructionContentViewController;
}
- (NSInteger)presentationCountForPageViewController:(UIPageViewController *)pageViewController
{
return [self.pageTitles count];
}
- (NSInteger)presentationIndexForPageViewController:(UIPageViewController *)pageViewController
{
return 0;
}
#end

Answer 1

it is possible that a syntax error exists in one of the files you #import, either InstructionContentViewController.h or StorageViewController.h.
Due to how imports are handled, the warning can sometimes show up in unexpected place. Verify that those are well-formed, as well as any other files that may be imported from those.
Also, within Xcode you can click on the "Product" menu and hold the Option key for a 'Clean Build Folder' command. This will clear out pre-compiled data and force everything to be recompiled from scratch.