iOS-集合视图-UIcollectionView

//
// ViewController.m
// UI20_UIcollectionView
//
// Created by YIem on 16/3/8.
// Copyright © 2016年 YIem. All rights reserved.
//

import "ViewController.h"

import "CollectionViewCell.h"

@interface ViewController ()<UICollectionViewDataSource, UICollectionViewDelegate>

@end

@implementation ViewController

• (void)viewDidLoad {

  [super viewDidLoad];
  // Do any additional setup after loading the view, typically from a nib.
  self.view.backgroundColor = [UIColor whiteColor];
  self.navigationItem.title = @"YIem";
  
  // UICollectionViewFlowLayout 是一个抽象类, 一般使用他的子类
  UICollectionViewFlowLayout *flowL= [[[UICollectionViewFlowLayout alloc] init] autorelease];
  // 注意 垂直与滚动方向的 是一行
  // 注意, 最小- 系统会尽可能的向设置值靠近, 却不会小设置的最小值
  // 最小行间距
  flowL.minimumLineSpacing = 100;
  // 最小列间距
  flowL.minimumInteritemSpacing = 10;
  // 单元大小
  flowL.itemSize = CGSizeMake(20, 20);
  // 区头间距
  flowL.headerReferenceSize = CGSizeMake(5, 5);
  // 区脚间距
  flowL.footerReferenceSize = CGSizeMake(5, 5);
  // 与屏幕四边的距离
  flowL.sectionInset = UIEdgeInsetsMake(10, 30, 10, 30);
  // 滚动方向
  flowL.scrollDirection = UICollectionViewScrollDirectionHorizontal;
  
  // 参数1:界面大小
  // 参数2:布局
  UICollectionView *collectionV = [[UICollectionView alloc] initWithFrame:self.view.frame collectionViewLayout:flowL];
  collectionV.backgroundColor = [UIColor greenColor];
  collectionV.delegate = self;
  collectionV.dataSource = self;
  [self.view addSubview:collectionV];
  [collectionV release];
  
  // 注册cell(重用)
  [collectionV registerClass:[CollectionViewCell class] forCellWithReuseIdentifier:@"cell"];
  
  

}

• (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section
  {
  return 100;
  }
• (UICollectionViewCell )collectionView:(UICollectionView )collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
  {
  CollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"cell" forIndexPath:indexPath];
  // cell.backgroundColor = [UIColor redColor];

  // CollectionViewCell *a = [[CollectionViewCell alloc] init];
  cell.label.text =[NSString stringWithFormat:@"%ld", indexPath.row];
  return cell;

  }

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

@end

//
// CollectionViewCell.h
// UI20_UIcollectionView
//
// Created by YIem on 16/3/8.
// Copyright © 2016年 YIem. All rights reserved.
//

import <UIKit/UIKit.h>

@interface CollectionViewCell : UICollectionViewCell

• (instancetype)initWithFrame:(CGRect)frame;
• (void)econt;
  @property (nonatomic, retain) UILabel *label;

@end

//
// CollectionViewCell.m
// UI20_UIcollectionView
//
// Created by YIem on 16/3/8.
// Copyright © 2016年 YIem. All rights reserved.
//

import "CollectionViewCell.h"

@implementation CollectionViewCell

• (instancetype)initWithFrame:(CGRect)frame
  {
  self = [super initWithFrame:frame];
  if (self) {

  [self econt];

  }
  return self;
  }

• (void)econt
  {
  self.label = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, 100, 50)];
  _label.backgroundColor = [UIColor cyanColor];
  _label.text = @"YIem";
  [self.contentView addSubview:_label];
  [_label release];
  }

@end