collectionView经常用在商品展示(淘宝),图片展示等APP上,作用和用法和tableView差不多,最大的不同点是:collectionView里面有个瀑布流的用法,它可以在竖直滑动的情况下一横排不知可以铺一个cell,它可以铺很多cell.我觉得以后在APP项目中会出现越来越多的collectionView.上代码:
#import "ViewController.h"
#import "MyCell.h"
#import "UIImageView+WebCache.h"
@interface ViewController ()<UICollectionViewDelegate,UICollectionViewDataSource>
@property(nonatomic, strong)NSMutableArray *arr;
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
//这是苹果给我们提供一种瀑布流
UICollectionViewFlowLayout *layout = [[UICollectionViewFlowLayout alloc]init];
//layout设置item的尺寸
layout.itemSize = CGSizeMake(120, 160);
//最小的行间距
layout.minimumLineSpacing = 30;
//最小的列间距
layout.minimumInteritemSpacing = 10;
//修改滚动的方向,默认是垂直的方向
//layout.scrollDirection = UICollectionViewScrollDirectionHorizontal;
//距离屏幕四边的距离
layout.sectionInset = UIEdgeInsetsMake(10, 10, 10, 10);
//layout.headerReferenceSize = CGSizeMake(200, 200);
UICollectionView *collection = [[UICollectionView alloc]initWithFrame:self.view.frame collectionViewLayout:layout
];
collection.delegate = self;
collection.dataSource = self;
collection.backgroundColor = [UIColor orangeColor];
[self.view addSubview:collection];
//注册
[collection registerClass:[MyCell class] forCellWithReuseIdentifier:@"cell"];
[self creatData];
}
-(void)creatData{
NSString *path = [[NSBundle mainBundle]pathForResource:@"Data" ofType:@"json"];
NSData *data = [NSData dataWithContentsOfFile:path];
self.arr = [NSJSONSerialization JSONObjectWithData:data options:0 error:nil];
}
-(NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section{
return self.arr.count;
}
-(UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath{
MyCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"cell" forIndexPath:indexPath] ;
cell.contentView.backgroundColor = [UIColor cyanColor];
cell.nameLable.text = [NSString stringWithFormat:@"%ld",indexPath.row];
[cell.picImage sd_setImageWithURL:[NSURL URLWithString:self.arr[indexPath.row][@"thumbURL"]]];
return cell;
}
-(void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath{
NSLog(@"%ld",indexPath.row);
}
下面是cell文件:
//cell.h文件
#import <UIKit/UIKit.h>
@interface MyCell : UICollectionViewCell
@property(nonatomic, retain)UILabel *nameLable;
@property(nonatomic, retain)UIImageView *picImage;
@end
//cell.m文件
#import "MyCell.h"
@implementation MyCell
-(instancetype)initWithFrame:(CGRect)frame{
self = [super initWithFrame:frame];
if (self) {
[self creatView];
}
return self;
}
-(void)creatView{
self.picImage = [[UIImageView alloc]initWithFrame:CGRectMake(0, 0, self.contentView.frame.size.width, self.contentView.frame.size.height - 50)];
[self.contentView addSubview:self.picImage];
self.nameLable = [[UILabel alloc]initWithFrame:CGRectMake(0, self.contentView.frame.size.height - 50, self.contentView.frame.size.width, 50)];
[self.contentView addSubview:self.nameLable];
}
@end