【请教】关于 仿新浪微博下拉刷新Listview！！

Posted 2023-05-12

在网上看到很多所谓的 仿新浪微博下拉刷新 Listview。。。 搜索引擎一搜一大把，但是细看其实都是PullToRefreshListView这个控件。 PullToRefreshListView这个控件，做android的肯定不陌生，是一个外国人写的控件（继承Listview） 一直拿来主义的我，却发现这个控件其实并不出色，下拉到可刷新位置时会卡顿，而且经常卡住。 但是，看到许多应用中的这一控件却十分流程（新浪微博，网易新闻，陌陌（这个尤为的好，下拉时箭头是随用户拉动而旋转的）。。。） 所以，不禁怀疑，他们并不是使用的这个网上流传的控件。 是不是使用的ScrollView呢？求真相

参考技术A 呵呵，抱歉啊，没细看，你这个问题就是shenallan所说的了，处理问题，onTouchEvent里没处理好 参考技术B 这个流不流畅关键看touch事件的处理吧。用什么控件应该差不大吧 参考技术C OnScrollListener和OnTouchListener一块用就哦了

IOS 使用SDWebImage实现仿新浪微博照片浏览器

　　使用第三方库SDWebImage实现仿新浪微博照片浏览器，可以下载图片缓存，点击之后滚动查看相片，具体效果如下：　　　　                  

代码如下：

WeiboImageView.h：

#import <UIKit/UIKit.h>

@interface WeiboImageView : UIImageView

@property (nonatomic, assign) CGRect originRect;

- (instancetype)initWithFrame:(CGRect)frame;

@end

WeiboImageView.m

#import "WeiboImageView.h"

@implementation WeiboImageView

@synthesize originRect;

- (instancetype)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        originRect = frame;
        self.clipsToBounds = YES;
        self.userInteractionEnabled  = YES;
        self.contentMode = UIViewContentModeScaleAspectFill;
        
    }
    return self;
}

- (void)dealloc
{
    
}


@end

WeiboImageBrowser.h

#import <UIKit/UIKit.h>

@interface WeiboImageBrowser : UIView<UIScrollViewDelegate>

//@property (nonatomic, copy) NSArray *imageViewArray;

@property (nonatomic, assign) int currentSelectedIamge;

@property (nonatomic, strong) UIScrollView *backgroundScrollView;

@property (nonatomic, strong) UILabel *pageIndexLabel;

@property (nonatomic,strong) NSMutableArray *originRects;

@property (nonatomic, copy) NSArray *bigImageArray;

- (instancetype)initWithFrame : (CGRect)rect;

- (void)showWeiboImages;

@end

WeiboImageBrowser.m

#import "WeiboImageBrowser.h"
#import "WeiboDefine.h"
#import "WeiboImageView.h"
#import "SDImageCache.h"      //缓存相关
#import "SDWebImageCompat.h"  //组件相关
#import "SDWebImageDecoder.h" //解码相关

//图片下载以及下载管理器
#import "SDWebImageDownloader.h"
#import "SDWebImageManager.h"
#import "SDWebImageDownloaderOperation.h"

@implementation WeiboImageBrowser

//@synthesize imageViewArray;

@synthesize currentSelectedIamge;

@synthesize bigImageArray;


- (instancetype)initWithFrame : (CGRect)rect
{
    self = [super initWithFrame:rect];
    if (self) {
        [self addSubview:self.pageIndexLabel];
        self.backgroundColor = [UIColor blackColor];
        [self initBackgroundScrollView];
    }
    return self;
}

- (UIScrollView *)backgroundScrollView
{
    if (!_backgroundScrollView) {
        _backgroundScrollView = [[UIScrollView alloc]initWithFrame:CGRectMake(0, 0, UISCREEN_WIDTH, UISCREEN_HEIGHT)];
        _backgroundScrollView.pagingEnabled = YES;
    }
    return _backgroundScrollView;
}

- (NSMutableArray *)originRects
{
    if (!_originRects) {
        _originRects = [NSMutableArray array];
    }
    return _originRects;
}

- (UILabel *)pageIndexLabel
{
    if (!_pageIndexLabel) {
        _pageIndexLabel = [[UILabel alloc]initWithFrame:CGRectMake((UISCREEN_WIDTH - 100) / 2, UISCREEN_HEIGHT - 50, 100, 25)];
        _pageIndexLabel.textAlignment = NSTextAlignmentCenter;
        _pageIndexLabel.textColor = [UIColor whiteColor];
        _pageIndexLabel.font = [UIFont fontWithName:@"Arial" size:20];
    }
    return _pageIndexLabel;
}

- (void)initBackgroundScrollView
{
    self.backgroundScrollView.contentSize = CGSizeMake([self.bigImageArray count] * UISCREEN_WIDTH, UISCREEN_HEIGHT);
    self.backgroundScrollView.delegate = self;
    self.backgroundScrollView.showsHorizontalScrollIndicator = NO;
    [self addSubview:self.backgroundScrollView];
}

- (void)initImageScrollViews
{
    self.backgroundScrollView.contentSize = CGSizeMake([self.bigImageArray count] * UISCREEN_WIDTH, 0);
    self.backgroundScrollView.contentOffset = CGPointMake(currentSelectedIamge * UISCREEN_WIDTH, 0);
    for (int i = 0; i < [self.bigImageArray count]; i++) {
        [[SDWebImageManager sharedManager] downloadImageWithURL:[NSURL URLWithString:[self.bigImageArray objectAtIndex:i] ] options:0
                                                       progress:^(NSInteger receivedSize, NSInteger expectedSize)
         {
             NSLog(@"progress!!!");
         }
         
                                                      completed:^(UIImage *image, NSError *error, SDImageCacheType cacheType, BOOL finished, NSURL *imageURL)
         {
             UIScrollView *iamgeScrollView = [[UIScrollView alloc]initWithFrame:CGRectMake(UISCREEN_WIDTH * i, 0, UISCREEN_WIDTH, UISCREEN_HEIGHT)];
             WeiboImageView *weibImageView = [[WeiboImageView alloc]init];
             weibImageView.image = image;
             CGFloat ratio = (double)weibImageView.image.size.height / (double)weibImageView.image.size.width;
             weibImageView.bounds = CGRectMake(0, 0, UISCREEN_WIDTH, UISCREEN_WIDTH * ratio);
             weibImageView.center = CGPointMake(UISCREEN_WIDTH / 2, UISCREEN_HEIGHT / 2);
             UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(imageTap:)];
             [weibImageView addGestureRecognizer:tap];
             [iamgeScrollView addSubview:weibImageView];
             [self.backgroundScrollView addSubview:iamgeScrollView];
         }];
    }
}

- (void)showWeiboImages
{
    [self initImageScrollViews];
    [[UIApplication sharedApplication].keyWindow addSubview:self];
}


-(void)imageTap:(UITapGestureRecognizer *)tap
{
    [self removeFromSuperview];
}

- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView
{
    int nCurrentPage = scrollView.contentOffset.x / UISCREEN_WIDTH;
    currentSelectedIamge = nCurrentPage;
    NSString *stringPage = [NSString stringWithFormat:@"%d/%d",nCurrentPage + 1, [self.bigImageArray count]];
    self.pageIndexLabel.text = stringPage;
    [self bringSubviewToFront:self.pageIndexLabel];
}


@end

使用方法：

ViewController.h

#import <UIKit/UIKit.h>

@interface ViewController : UIViewController

@property (nonatomic, strong)NSArray *imageArray;

@end

ViewController.m

#import "ViewController.h"
#import "SDImageCache.h"      //缓存相关
#import "SDWebImageCompat.h"  //组件相关
#import "SDWebImageDecoder.h" //解码相关

//图片下载以及下载管理器
#import "SDWebImageDownloader.h"
#import "SDWebImageManager.h"
#import "SDWebImageDownloaderOperation.h"
#import "WeiboDefine.h"
#import "WeiboImageView.h"
#import "WeiboImageBrowser.h"

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    float imageWidth = (UISCREEN_WIDTH - 50) / 3.0;
    _imageArray = [NSArray arrayWithObjects:
                           @"http://g.hiphotos.baidu.com/image/pic/item/c2cec3fdfc03924578c6cfe18394a4c27c1e25e8.jpg",
                           @"http://image.tianjimedia.com/uploadImages/2015/072/23/4X4L0E9BNEZ6.jpg",
                           @"http://img15.3lian.com/2015/c1/83/d/31.jpg",
                           @"http://img15.3lian.com/2015/c1/83/d/31.jpg",
                           @"http://img15.3lian.com/2015/c1/83/d/31.jpg",
                           @"http://img15.3lian.com/2015/c1/83/d/31.jpg",
                           @"http://img15.3lian.com/2015/c1/83/d/31.jpg",
                           @"http://img15.3lian.com/2015/c1/83/d/31.jpg",
                           @"http://img15.3lian.com/2015/c1/83/d/31.jpg",nil  ] ;
    int n = _imageArray.count;
    
    for (int i = 0; i < n; i++) {
        [[SDWebImageManager sharedManager] downloadImageWithURL:[NSURL URLWithString:[_imageArray objectAtIndex:i]
                                                                                      ] options:0
                                                       progress:^(NSInteger receivedSize, NSInteger expectedSize)
         {
             NSLog(@"progress!!!");
         }
         
                                                      completed:^(UIImage *image, NSError *error, SDImageCacheType cacheType, BOOL finished, NSURL *imageURL)
         {
             CGRect rect = CGRectMake(15 + (i % 3) * (imageWidth + 10) , 20 + 90 + (i / 3) * (imageWidth + 10), imageWidth, imageWidth);
             UIImageView *imageView = [[UIImageView alloc]initWithFrame:rect];
             imageView.image = image;
             imageView.frame = rect;
             imageView.clipsToBounds = YES;
             imageView.contentMode = UIViewContentModeScaleAspectFill;
             imageView.tag = i;
             imageView.userInteractionEnabled = YES;
             UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(imageTap:)];
             [imageView addGestureRecognizer:tap];
             [self.view addSubview:imageView];
             
         }];
    }


    // Do any additional setup after loading the view, typically from a nib.
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    
    // Dispose of any resources that can be recreated.
}

-(void)imageTap:(UITapGestureRecognizer *)tap
{
    WeiboImageBrowser *imageBrowser = [[WeiboImageBrowser alloc] initWithFrame:CGRectMake(0, 0, UISCREEN_WIDTH, UISCREEN_HEIGHT)];
    imageBrowser.currentSelectedIamge = tap.view.tag;
    imageBrowser.bigImageArray = /*weiboInformation.pic_urls*/_imageArray;
    [imageBrowser showWeiboImages];
}

@end

 源代码下载链接：http://download.csdn.net/detail/lzm2625347497/9615067