UICollectionView请求网络数据显示(Text)

TEXT:

AppDelegate.m

    self.window.rootViewController = [[[UINavigationController alloc]initWithRootViewController:[RootViewController new]]autorelease];

RootViewController.m

#import "RootViewController.h"
#import "ImageCell.h"
#import "ImageURL.h"
#define kImageCell @"imagecell"
@interface RootViewController ()<UICollectionViewDataSource>
@property(nonatomic,retain)NSMutableArray *dataSource;//存储model对象
@end

//释放
- (void)dealloc
{
    self.dataSource = nil;
    [super dealloc];
}
//懒加载
- (NSMutableArray *)dataSource{

    if (_dataSource == nil) {
        self.dataSource = [NSMutableArray arrayWithCapacity:0];
    }
    return [[_dataSource retain]autorelease];
}

- (void)viewDidLoad {
    [super viewDidLoad];
    self.view.backgroundColor = [UIColor whiteColor];
    //调用配置CollectionView
    [self confgureCollectionView];
    //调用解析
    [self readDataFromFile];

}

解析数据：

- (void)readDataFromFile{
    //获取文件的路径
    NSString *filePath = [[NSBundle mainBundle]pathForResource:@"Data.json" ofType:nil];
    //使用文件的初始化NSData对象
    NSData *data = [NSData dataWithContentsOfFile:filePath];
    //使用json解析
 NSMutableArray *sourceArray =  [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableContainers  error:nil];
//    NSLog(@"%@",sourceArray);
    //遍历字典
    for (NSDictionary *dic in sourceArray) {
        //创建model对象
        ImageURL *URL = [[ImageURL alloc]init];
        //添加到model
        [URL setValuesForKeysWithDictionary:dic];
        //添加到数组
        [self.dataSource addObject:URL];
        NSLog(@"%@",self.dataSource);

    }
}

配置CollectionView

//配置CollectionView
- (void)confgureCollectionView{
    //创建布局工具
    UICollectionViewFlowLayout *flowLayout = [[UICollectionViewFlowLayout alloc]init];
    //设置item的大小
    flowLayout.itemSize = CGSizeMake(140, 160);
    //设置分区缩进量
    flowLayout.sectionInset = UIEdgeInsetsMake(5, 10, 5, 10);

    //创建CollectionView对象
    UICollectionView *collectionView = [[UICollectionView alloc]initWithFrame:[UIScreen mainScreen].bounds collectionViewLayout:flowLayout];
    //配置数据源代理
    collectionView.dataSource = self;
    //注册cell
    [collectionView registerClass:[ImageCell class] forCellWithReuseIdentifier:kImageCell];
    //设置背景颜色
    collectionView.backgroundColor = [UIColor whiteColor];  

    //添加到父视图上
    [self.view addSubview:collectionView];
    [collectionView release];
    [flowLayout release];

}

#pragma mark 数据源代理方法

//返回分区个数
- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section{

    return self.dataSource.count;

}
- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath{
    ImageCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:kImageCell forIndexPath:indexPath];
    //根据item的下标取出对应位置的数据
    ImageURL *url = self.dataSource[indexPath.item];
    //调用cell控件赋值的方法
    [cell assignValueByImageURL:url];

    return cell;
}

自定义cell：

<span style="font-size:24px;">//ImageCell.h
#import <UIKit/UIKit.h>
@class ImageURL;
@interface ImageCell : UICollectionViewCell
//写一个方法给cell上控件赋值
- (void)assignValueByImageURL : (ImageURL *)image;
@end

//ImageCell.m
#import "ImageCell.h"
#import "UIImageView+WebCache.h"
#import "ImageURL.h"
@interface ImageCell ()
@property(nonatomic,retain)UIImageView *photoView;
@end

@implementation ImageCell
- (void)dealloc
{
    self.photoView = nil;
    [super dealloc];
}
- (id)initWithFrame:(CGRect)frame{
    if (self = [super initWithFrame:frame]) {

        [self.contentView addSubview:self.photoView];

    }
    return self;
}

- (UIImageView *)photoView{

    if (_photoView == nil) {
        self.photoView = [[UIImageView alloc]initWithFrame:self.bounds];
        self.photoView.backgroundColor = [UIColor cyanColor];

    }
    return [[_photoView retain]autorelease];

}
//写一个方法给cell上控件赋值
- (void)assignValueByImageURL : (ImageURL *)image{
    //1.使用图片异步加载
    [self.photoView sd_setImageWithURL:[NSURL URLWithString:image.thumbURL] placeholderImage:[UIImage imageNamed:@"占位1"]];
}
@end</span>

建一个model数据类：

<span style="font-size:24px;">//ImageURL.h
@interface ImageURL : NSObject
@property(nonatomic,copy)NSString *thumbURL;
@end

//ImageURL.m
#import "ImageURL.h"

@implementation ImageURL
- (void)dealloc
{
    self.thumbURL= nil;
    [super dealloc];
}

//防止Crash
- (void)setValue:(id)value forUndefinedKey:(NSString *)key{
}
@end</span>

效果展示：

图片占位：

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Data文件下载：http://pan.baidu.com/s/1ntw5W3f

本节知识点：http://blog.csdn.net/qq_31810357/article/details/49154985