IOS 开发之网络图片轮播图的实现

IOS 开发之网络图片轮播图的实现

截图

1.使用

LJPhotoGroupView *_ljPhotoGroupView = [[LJPhotoGroupView alloc]initWithItem:self.ljUrlArray];
_ljPhotoGroupView.backgroundColor = [UIColor blackColor];
_ljPhotoGroupView.frame = CGRectMake(0, 0, kDEVICEWIDTH, kDEVICEHEIGHT);
[_ljPhotoGroupView showHintView:self]; 

2.源码

#import "LJPhotoGroupView.h"
#import "LJWebIDataManager.h" 

@interface LJPhotoGroupCellView() 

@property (nonatomic, strong) UIImageView *ljImageview; 

@end 

@implementation LJPhotoGroupCellView 

- (instancetype)initWithFrame:(CGRect)frame url:(NSString*)imageurl
{
  self = [super initWithFrame:frame];
  if (self) {
    [self addSubview:self.ljImageview];
    ／／这里大家可以换成自己的网络请求图片的方法
    [[LJWebIDataManager sharedInstances]retrieveData:imageurl successBlock:^(NSData *netData, NSString *progressStr, BOOL isFinished) {
      //在主线程中刷新界面
      dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{ 

        UIImage *_ljImage = [UIImage imageWithData: netData scale:0.3];
        @myWeakify(self);
        dispatch_async(dispatch_get_main_queue(), ^{
          @myStrongify(self);
          self.ljImageview.image = _ljImage;
        });
      });
    }];
  }
  return self;
} 

- (UIImageView*)ljImageview
{
  if (!_ljImageview) {
    _ljImageview = UIImageView.new;
    _ljImageview.frame = CGRectMake(15, 0, kDEVICEWIDTH - 30, 130);
    _ljImageview.backgroundColor = [UIColor redColor];
    UIGestureRecognizer *_tap = [[UIGestureRecognizer alloc]initWithTarget:self action:@selector(dismissHintView)];
    [_ljImageview addGestureRecognizer:_tap];
  }
  return _ljImageview;
} 

@end 

@interface LJPhotoGroupView()<UIScrollViewDelegate> 

@property (nonatomic, strong) UIScrollView *ljScrollView;
@property (nonatomic, strong) NSArray *ljItemArray;
@property (nonatomic, strong) UIImageView *ljImageview;
@property (nonatomic, strong) UIPageControl *ljPageControl; 

@end 

@implementation LJPhotoGroupView 

- (instancetype)initWithItem:(NSArray*)ljArray
{
  self = [super init];
  if (self)
  {
    self.ljItemArray = [NSArray arrayWithArray:ljArray]; 

    [self addSubview:self.ljScrollView];
    [self addSubview:self.ljPageControl]; 

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

      //方法一：直接设置每个cell的X坐标
//      LJPhotoGroupCellView *_cell = [[LJPhotoGroupCellView alloc]initWithFrame:CGRectMake((kDEVICEWIDTH )*i, 0, kDEVICEWIDTH, 130) url:self.ljItemArray[i]]; 

      //方法二:先不用考虑cell的X坐标，在下面设置X的坐标
      LJPhotoGroupCellView *cell = [[LJPhotoGroupCellView alloc]initWithFrame:self.ljScrollView.bounds url:self.ljItemArray[i]];
      UITapGestureRecognizer *_tap = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(dismissHintView)];
        [cell addGestureRecognizer:_tap];
      [self.ljScrollView addSubview:cell];
    } 

    //方法二:设置cell的X坐标
    // 计算imageView的位置
    [self.ljScrollView.subviews enumerateObjectsUsingBlock:^(LJPhotoGroupCellView *cell, NSUInteger idx, BOOL *stop)
     {
      // 调整x => origin => frame
      CGRect frame = cell.frame;
      frame.origin.x = idx * frame.size.width; 

      cell.frame = frame;
    }]; 

    self.ljPageControl.currentPage = 0;
  }
  return self;
} 

- (UIScrollView*)ljScrollView
{
  if (!_ljScrollView)
  {
    _ljScrollView = UIScrollView.new;
    _ljScrollView.frame = CGRectMake(0, 250, kDEVICEWIDTH, 130);
    _ljScrollView.delegate = self;
    //_scrollView.scrollsToTop = NO;
    _ljScrollView.pagingEnabled = YES;
    _ljScrollView.contentSize = CGSizeMake(_ljScrollView.bounds.size.width * self.ljItemArray.count, 130);
    //_scrollView.alwaysBounceHorizontal = groupItems.count > 1;
    // _scrollView.showsHorizontalScrollIndicator = NO;
    //_scrollView.showsVerticalScrollIndicator = NO;
    //_scrollView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
    //_scrollView.delaysContentTouches = NO;
    //_scrollView.canCancelContentTouches = YES;
  }
  return _ljScrollView;
} 

- (UIPageControl *)ljPageControl
{
  if (_ljPageControl == nil)
  {
    // 分页控件，本质上和scrollView没有任何关系，是两个独立的控件
    _ljPageControl = [[UIPageControl alloc] init];
    // 总页数
    _ljPageControl.numberOfPages = self.ljItemArray.count;
    CGSize size = [_ljPageControl sizeForNumberOfPages:self.ljItemArray.count]; 

    _ljPageControl.bounds = CGRectMake(0, 0, size.width, size.height);
    _ljPageControl.center = CGPointMake(self.center.x, 380); 

    // 设置颜色
    _ljPageControl.pageIndicatorTintColor = [UIColor redColor];
    //当前页面的颜色
    _ljPageControl.currentPageIndicatorTintColor = [UIColor whiteColor];
    [_ljPageControl addTarget:self action:@selector(pageChanged:) forControlEvents:UIControlEventValueChanged];
  }
  return _ljPageControl;
} 

// 分页控件的监听方法
- (void)pageChanged:(UIPageControl *)page
{
  NSLog(@"%ld", (long)page.currentPage); 

  // 根据页数，调整滚动视图中的图片位置 contentOffset self.scrollView.bounds.size.width
  CGFloat x = page.currentPage * (kDEVICEWIDTH);
  [self.ljScrollView setContentOffset:CGPointMake(x, 0) animated:YES];
} 

- (UIImageView*)ljImageview
{
  if (!_ljImageview) {
    _ljImageview = UIImageView.new;
    _ljImageview.frame = CGRectMake(0, 0, kDEVICEWIDTH, kDEVICEHEIGHT);
    _ljImageview.backgroundColor = [UIColor redColor]; 

    UIGestureRecognizer *_tap = [[UIGestureRecognizer alloc]initWithTarget:self action:@selector(dismissHintView)];
    [_ljImageview addGestureRecognizer:_tap];
  }
  return _ljImageview;
} 

- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
  //CGFloat floatPage = _scrollView.contentOffset.x / _scrollView.width;
  //NSInteger page = _scrollView.contentOffset.x / _scrollView.width;
} 

- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate{
  if (!decelerate) {
  }
} 

#pragma mark - ScrollView的代理方法
// 滚动视图停下来，修改页面控件的小点（页数）
- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView
{
  // 停下来的当前页数
  NSLog(@"%@", NSStringFromCGPoint(scrollView.contentOffset)); 

  // 计算页数
  int page = scrollView.contentOffset.x / scrollView.bounds.size.width; 

  self.ljPageControl.currentPage = page;
} 

- (void)showHintView:(UIView*)view
{
  //[view addSubview:self];
   [[UIApplication sharedApplication].delegate.window.rootViewController.view addSubview:self]; 

  self.alpha = 0.0;
  [UIView animateWithDuration:0.3 delay:0 options:UIViewAnimationOptionCurveEaseOut animations:^{ 

    self.alpha = 1.0; 

  } completion:^(BOOL finished)
   { 

   }];
} 

- (void)dismissHintView
{
  [UIView animateWithDuration:0.3 delay:0 options:UIViewAnimationOptionCurveEaseIn animations:^{ 

    self.alpha = 0.0; 

  } completion:^(BOOL finished){ 

    [self removeFromSuperview];
  }];
} 

@end

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