Unlimited scrolling Scrollview effect in IOS
- 2020-05-13 03:30:47
- OfStack
In this article, the example of IOS infinite scrolling effect, to share with you for your reference, the specific content is as follows
Swipe to the current position to request, and local content is displayed directly (SDWebImage,UIView+Ext)
HZScrollView.h
#import <UIKit/UIKit.h>
typedef void(^HZReturnBlock)(NSInteger index,CGFloat offset);
typedef NS_ENUM(NSUInteger, HZScrollViewPageControllPosition) {
HZScrollViewPageControllPositionNone,
HZScrollViewPageControllPositionLeft,
HZScrollViewPageControllPositionCenter,
HZScrollViewPageControllPositionRight,
};
@class HZScrollView;
@protocol HZScrollViewDelegate <NSObject>
@optional
- (void)resetPosition:(HZScrollView *)scrollView AndIndex:(NSInteger)index;
@end
@interface HZScrollView : UIView
/**
* Return to current position
*/
@property (nonatomic, weak)id <HZScrollViewDelegate>delegate;
/**
* The default diagram
*/
@property (nonatomic, strong) UIImage *hz_placeImage;
/**
* Picture list wow
*/
@property (nonatomic, strong) NSArray *hz_ImageList;
/**
* pagecongroll location
*/
@property (nonatomic, assign) HZScrollViewPageControllPosition hz_PageControllPosition;
/**
* Transform itself frame
*
* @param offset The offset
*/
- (void)transformView:(CGFloat)offset;
/**
* Get the current location as well as cheap
*
* @param block Returns the content
*/
- (void)hz_getContent:(HZReturnBlock)block;
@end
HZScrollView.m
#import "UIImageView+WebCache.h"
#import "HZScrollView.h"
#import "UIView+DylanFramTool.h"
#define HZ_FormatImage(val_imageView)\
- (UIImageView *)val_imageView\
{\
if (!_##val_imageView) {\
_##val_imageView = [[UIImageView alloc] init];\
}\
return _##val_imageView;\
}\
// The width of the
#define HZ_SWidth self.bounds.size.width
// highly
#define HZ_SHeight self.bounds.size.height
#define HZ_PHeight 16
@interface HZScrollView ()<UIScrollViewDelegate>
@property (nonatomic, copy) HZReturnBlock hz_block;
/**
* The total number of
*/
@property (nonatomic,assign) NSInteger hz_MaxCount;
/**
* The current position
*/
@property (nonatomic,assign) NSInteger hz_currentIndex;
/**
* The container
*/
@property (nonatomic, strong) UIScrollView *scrollView;
/**
* You know what drop
*/
@property (nonatomic, strong) UIPageControl *pageControll;
/** view **/
@property (nonatomic, strong) UIImageView *leftImageView;
@property (nonatomic, strong) UIImageView *centerImageView;
@property (nonatomic, strong) UIImageView *rightImageView;
@end
@implementation HZScrollView
{
CGRect _hz_Frame;
}
#pragma mark -
#pragma mark - init
- (instancetype)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
_hz_Frame = frame;
[self addSubview:self.scrollView];
[self configImageView];
[self addSubview:self.pageControll];
}
return self;
}
#pragma mark -
#pragma mark - config
- (void)configImageView
{
self.leftImageView.frame = CGRectMake(0, 0, HZ_SWidth, HZ_SHeight);
[self.scrollView addSubview:self.leftImageView];
self.centerImageView.frame = CGRectMake(HZ_SWidth, 0, HZ_SWidth, HZ_SHeight);
[self.scrollView addSubview:self.centerImageView];
self.rightImageView.frame = CGRectMake(HZ_SWidth * 2, 0, HZ_SWidth, HZ_SHeight);
[self.scrollView addSubview:self.rightImageView];
}
#pragma mark -
#pragma mark - reSet
- (void)setHz_placeImage:(UIImage *)hz_placeImage
{
_hz_placeImage = hz_placeImage;
[self changeImageLeft:-1 center:-1 right:-1];
if (self.hz_MaxCount) {
[self setHz_MaxCount:self.hz_ImageList.count];
}
}
- (void)setHz_ImageList:(NSArray *)hz_ImageList
{
_hz_ImageList = [hz_ImageList copy];
[self setHz_MaxCount:_hz_ImageList.count];
}
- (void)setHz_MaxCount:(NSInteger)hz_MaxCount
{
_hz_MaxCount = hz_MaxCount;
switch (_hz_MaxCount) {
case 0:
self.scrollView.scrollEnabled = NO;
[self changeImageLeft:-1 center:-1 right:-1];
break;
case 1:
self.scrollView.scrollEnabled = NO;
[self changeImageLeft:0 center:0 right:0];
break;
default:
self.scrollView.scrollEnabled = YES;
[self changeImageLeft:_hz_MaxCount - 1 center:0 right:1];
break;
}
self.pageControll.numberOfPages = _hz_MaxCount;
[self setHz_PageControllPosition:_hz_PageControllPosition];
}
- (void)setHz_PageControllPosition:(HZScrollViewPageControllPosition)hz_PageControllPosition
{
_hz_PageControllPosition = hz_PageControllPosition;
CGFloat width = self.hz_MaxCount * HZ_PHeight;
switch (_hz_PageControllPosition) {
case HZScrollViewPageControllPositionNone:
self.pageControll.hidden = YES;
break;
case HZScrollViewPageControllPositionLeft:
self.pageControll.hidden = NO;
self.pageControll.frame = CGRectMake(10, self.pageControll.frame.origin.y, width, self.pageControll.frame.size.height);
break;
case HZScrollViewPageControllPositionCenter:
self.pageControll.hidden = NO;
self.pageControll.frame = CGRectMake((self.bounds.size.width - width)/2.f, self.pageControll.frame.origin.y, width, self.pageControll.frame.size.height);
break;
case HZScrollViewPageControllPositionRight:
self.pageControll.hidden = NO;
self.pageControll.frame = CGRectMake(self.bounds.size.width - 10 - width, self.pageControll.frame.origin.y, width, self.pageControll.frame.size.height);
break;
default:
break;
}
if (width <= HZ_PHeight) {
self.pageControll.hidden = YES;
}
}
#pragma mark -
#pragma mark - LZ
- (UIScrollView *)scrollView
{
if (!_scrollView) {
_scrollView = [[UIScrollView alloc] initWithFrame:self.bounds];
_scrollView.pagingEnabled = YES;
_scrollView.showsHorizontalScrollIndicator = NO;
_scrollView.delegate = self;
_scrollView.contentSize = CGSizeMake(HZ_SWidth * 3,0);
}
return _scrollView;
}
- (UIPageControl *)pageControll
{
if (!_pageControll) {
_pageControll = [[UIPageControl alloc] initWithFrame:CGRectMake(0,HZ_SHeight - HZ_PHeight,HZ_PHeight, 7)];
_pageControll.pageIndicatorTintColor = [UIColor lightGrayColor];
_pageControll.currentPageIndicatorTintColor = [UIColor whiteColor];
_pageControll.numberOfPages = self.hz_MaxCount;
_pageControll.currentPage = 0;
}
return _pageControll;
}
HZ_FormatImage(leftImageView);
HZ_FormatImage(centerImageView);
HZ_FormatImage(rightImageView);
#pragma mark -
#pragma mark - private Method
- (void)changeImageWithOffset:(CGFloat)offsetX
{
if (offsetX >= HZ_SWidth * 2) {
self.hz_currentIndex++;
if (self.hz_currentIndex == self.hz_MaxCount - 1) {
[self changeImageLeft:self.hz_currentIndex - 1 center:self.hz_currentIndex right:0];
}else if (self.hz_currentIndex == self.hz_MaxCount) {
self.hz_currentIndex = 0;
[self changeImageLeft:self.hz_MaxCount - 1 center:0 right:1];
}else {
[self changeImageLeft:self.hz_currentIndex-1 center:self.hz_currentIndex right:self.hz_currentIndex + 1];
}
if (self.hz_block) {
self.hz_block(self.hz_currentIndex,offsetX);
}
self.pageControll.currentPage = self.hz_currentIndex;
}
if (offsetX <= 0) {
self.hz_currentIndex--;
if (self.hz_currentIndex == 0) {
[self changeImageLeft:self.hz_MaxCount-1 center:0 right:1];
}else if (self.hz_currentIndex == -1) {
self.hz_currentIndex = self.hz_MaxCount-1;
[self changeImageLeft:self.hz_currentIndex-1 center:self.hz_currentIndex right:0];
}else {
[self changeImageLeft:self.hz_currentIndex-1 center:self.hz_currentIndex right:self.hz_currentIndex+1];
}
if (self.hz_block) {
self.hz_block(self.hz_currentIndex,offsetX);
}
self.pageControll.currentPage = self.hz_currentIndex;
}
[self setHz_PageControllPosition:_hz_PageControllPosition];
}
- (void)changeImageLeft:(NSInteger)leftIndex center:(NSInteger)centerIndex right:(NSInteger)rightIndex
{
if (self.hz_currentIndex > self.hz_MaxCount) {
return;
}
if (leftIndex == -1 && centerIndex == -1 && rightIndex == -1) {
self.leftImageView.image = self.hz_placeImage;
self.centerImageView.image = self.hz_placeImage;
self.rightImageView.image = self.hz_placeImage;
} else {
[self checkExistImage:self.hz_ImageList[leftIndex]
ImageView:self.leftImageView
CurrentIndex:@(leftIndex)];
[self checkExistImage:self.hz_ImageList[centerIndex]
ImageView:self.centerImageView
CurrentIndex:@(centerIndex)] ;
[self checkExistImage:self.hz_ImageList[rightIndex]
ImageView:self.rightImageView
CurrentIndex:@(rightIndex)];
}
[self.scrollView setContentOffset:CGPointMake(HZ_SWidth, 0)];
}
- (void)checkExistImage:(NSString *)urlString
ImageView:(UIImageView *)currentImageView
CurrentIndex:(NSNumber *)index
{
if ([[[SDWebImageManager sharedManager] imageCache] imageFromDiskCacheForKey:urlString])
{
currentImageView.image = [[[SDWebImageManager sharedManager] imageCache] imageFromMemoryCacheForKey:urlString];
return;
} else {
currentImageView.image = self.hz_placeImage;
if (self.hz_currentIndex != [index integerValue]) {
return;
}
[self performSelector:@selector(downLoadImage:) withObject:@[urlString,currentImageView] afterDelay:0 inModes:@[NSDefaultRunLoopMode]];
}
}
- (void)downLoadImage:(NSArray *)param
{
NSString *urlString = [param firstObject];
__weak UIImageView *currentImageView = [param lastObject];
[[SDWebImageManager sharedManager] downloadImageWithURL:[NSURL URLWithString:urlString] options:0 progress:^(NSInteger receivedSize, NSInteger expectedSize) {
NSLog(@"received:%@",@(receivedSize));
} completed:^(UIImage *image, NSError *error, SDImageCacheType cacheType, BOOL finished, NSURL *imageURL) {
currentImageView.image = image;
// [[[SDWebImageManager sharedManager] imageCache] storeImage:image forKey:urlString];
[[[SDWebImageManager sharedManager] imageCache] storeImage:image forKey:urlString toDisk:YES];
}];
}
#pragma mark -
#pragma mark - UIScrollViewDelegate
- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
[self changeImageWithOffset:scrollView.contentOffset.x];
}
- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView
{
NSInteger index = scrollView.contentOffset.x/scrollView.width;
if ([self.delegate respondsToSelector:@selector(resetPosition:AndIndex:)]) {
[self.delegate resetPosition:self AndIndex:self.hz_currentIndex];
}
}
#pragma mark -
#pragma mark - public method
- (void)transformView:(CGFloat)offset
{
if (offset > 0) {
return;
}
CGFloat currentHeight = 210 - offset;
self.height = currentHeight ;
CGFloat currentScale = currentHeight / _hz_Frame.size.height;
self.left = _hz_Frame.origin.x - (_hz_Frame.size.width * currentScale - _hz_Frame.size.width)/2.f;
self.width = _hz_Frame.size.width * currentScale;
self.top = offset;
self.scrollView.size = self.size;
self.leftImageView.size = self.size;
self.centerImageView.size = self.size;
self.rightImageView.size = self.size;
self.centerImageView.x = self.width;
self.rightImageView.x = self.width * 2;
self.scrollView.contentSize = CGSizeMake(self.width *3, self.height);
[self.scrollView setContentOffset:CGPointMake(HZ_SWidth, 0)];
}
- (void)hz_getContent:(HZReturnBlock)block
{
self.hz_block = block;
}
- (void)layoutSubviews
{
[super layoutSubviews];
}
@endThe above is the entire content of this article, I hope to help you with your study.