Encapsulating paging functionality

#import <UIKit/UIKit.h>

@interface Lzjpageview:uiview

/** Picture name Data * /

@property (nonatomic, strong) Nsarray *imagenames;

+ (instancetype) PageView;

@end

#import "LZJPageView.h"

@interface Lzjpageview () <UIScrollViewDelegate>

@property (weak, nonatomic) iboutlet uiscrollview *scrollview;

@property (weak, nonatomic) iboutlet uipagecontrol *pagecontrol;

/** Timer * /

@property (nonatomic, weak) Nstimer *timer;

@end

@implementation Lzjpageview

-(void) awakefromnib

{

//1. whether to hide Pagecontrol When a single page

self. pagecontrol.hidesforsinglepage = YES;

//2. set up a picture of Pagecontrol

[self. Pagecontrol setvalue:[uiimage imagenamed:@ ' current '] Forkeypath:@ "_currentpageimage" ];

[self. Pagecontrol setvalue:[uiimage imagenamed:@ "Other"] Forkeypath: @ "_pageimage"];

//3. Turn on timer

[self starttimer];

}

+ (instancetype) PageView

{

return [[[NSBundle Mainbundle] Loadnibnamed:nsstringfromclass (self) owner:Nil options: Nil] lastobject];

}

-(void) Setimagenames: (Nsarray *) imagenames

{

_imagenames = Imagenames;

//0. removing the previously added

// let subviews every object in this array is executed removefromsuperview

[self. Scrollview.subviews makeobjectsperformselector:@selector(Removefromsuperview)];

//1. Create ImageView based on picture name Data to add to scrollView

CGFloat scrollvieww = self. scrollView.frame.size.width;

CGFloat SCROLLVIEWH = self. scrollView.frame.size.height;

Nsuinteger count = Imagenames.count;

for (int i = 0; i < count; i + +) {

Uiimageview *imageview = [[Uiimageview alloc] init];

Imageview.image = [UIImage imagenamed:imagenames[i]];

Imageview.frame = CGRectMake (i * scrollvieww, 0, SCROLLVIEWW, SCROLLVIEWH);

[self. ScrollView Addsubview:imageview];

}

//2. set contentsize

self. scrollview.contentsize = Cgsizemake (Count * scrollvieww, 0);

//3. Set Total pages

self. pagecontrol.numberofpages = count;

}

#pragma mark- timer-related code

-(void) Starttimer

{

// Returns an automatically executed timer object

self. timer = [Nstimer scheduledtimerwithtimeinterval:2.0 target:self selector:@selector (nextPage:) UserInfo:@ "123" repeats:YES];

[[Nsrunloop Mainrunloop] AddTimer:self. Timer formode:nsrunloopcommonmodes];

}

-(void) Stoptimer

{

[self. Timer invalidate];

}

/**

* Scroll to the next page

*/

-(void) NextPage: (Nstimer *) Timer

{

//1. Calculate the page number of the next page

Nsinteger page = self. Pagecontrol.currentpage + 1;

//2. more than the last page

if (page = = self . Imagenames.count) {

page = 0;

}

//3. Scroll to the next page

[self. ScrollView setcontentoffset:cgpointmake (page * self. ScrollView.frame.size.width, 0) Animated:YES];

}

#pragma mark-uiscrollviewdelegate

-(void) Scrollviewdidscroll: (Uiscrollview *) ScrollView

{

//1. calculate page Numbers

int page = (int) (scrollview.contentoffset.x/scrollview.frame.size.width + 0.5);

//2. set page numbers

self. pagecontrol.currentpage = page;

}

/**

* Stop timer when user is about to start dragging ScrollView

*/

-(void) scrollviewwillbegindragging: (Uiscrollview *) ScrollView

{

[self stoptimer];

}

/**

* When the user has stopped dragging the ScrollView, turn on the timer

*/

-(void) scrollviewdidenddragging: (Uiscrollview *) ScrollView willdecelerate: (BOOL) decelerate

{

[self starttimer];

}

@end

Encapsulating paging functionality