UI09_ControllerView(17-08-15)

//
//  ViewController.m
//  UI09_ControllerView
//
//  Created by lanou3g on 17/8/15.
//  Copyright © 2017年 lanou3g. All rights reserved.
//

#import "ViewController.h"
#import "ImageCell.h"

@interface ViewController () <UICollectionViewDelegate,UICollectionViewDataSource>

@property (nonatomic,retain) NSMutableArray *imageArray;

@end

@implementation ViewController

- (void)getData {
    self.imageArray = [NSMutableArray array];
    for (int i = 1; i <= 7; i++) {
        NSString *imageName = [NSString stringWithFormat:@"h%d.jpeg",i];
        UIImage *image = [UIImage imageNamed:imageName];
        [self.imageArray addObject:image];
    }
    
}

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    self.view.backgroundColor = [UIColor whiteColor];
    
    [self getData];
    
    //UICollectionViewLayout的子类,网格样式布局
    UICollectionViewFlowLayout *flowLayout = [[UICollectionViewFlowLayout alloc] init];
    //每个item的尺寸(collectionView会根据item的尺寸自动调整行数和列数)
    //7P屏幕宽度宽度 除得的结果为float型时，可能会出现四舍五入的情况,导致计算总和超出屏幕宽度，所以做一个取整舍弃小数部分的值
    flowLayout.itemSize = CGSizeMake((int)(self.view.bounds.size.width-4*10)/3, 200);
//    flowLayout.itemSize = CGSizeMake(self.view.bounds.size.width, 150);
    //滑动方向(系统默认垂直方向)
//    flowLayout.scrollDirection = UICollectionViewScrollDirectionHorizontal;
    //调整最小的间距(垂直方向滑动设置的是行的最小间距，水平方向滑动设置的是列的最小间距)
//    flowLayout.minimumLineSpacing = 0;
    //在垂直方向滑动：设置的是同一行item之间的间距
    //在水平方向滑动：设置的是同一列item之间的间距
    flowLayout.minimumInteritemSpacing = 0;
    
    flowLayout.sectionInset = UIEdgeInsetsMake(30, 10, 10, 10);
    
    //参数1:collectionView的frame
    //参数2:加载布局对象
    UICollectionView *collectionView = [[UICollectionView alloc] initWithFrame:self.view.bounds collectionViewLayout:flowLayout];
    collectionView.backgroundColor = [UIColor whiteColor];
    collectionView.delegate = self;
    collectionView.dataSource = self;
    
    //注册后直接重用
    [collectionView registerClass:[ImageCell class] forCellWithReuseIdentifier:@"cell"];
    
    [self.view addSubview:collectionView];
}
//
- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section {
    return self.imageArray.count;
}

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {
    ImageCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"cell" forIndexPath:indexPath];
    cell.contentView.backgroundColor = [UIColor orangeColor];
    cell.myImage = self.imageArray[indexPath.item];
    return cell;
}

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

@end

//
//  ImageCell.h
//  UI09_ControllerView
//
//  Created by lanou3g on 17/8/15.
//  Copyright © 2017年 lanou3g. All rights reserved.
//

#import <UIKit/UIKit.h>

@interface ImageCell : UICollectionViewCell

@property (nonatomic,retain) UIImage *myImage;

@end

//
//  ImageCell.m
//  UI09_ControllerView
//
//  Created by lanou3g on 17/8/15.
//  Copyright © 2017年 lanou3g. All rights reserved.
//

#import "ImageCell.h"

@interface ImageCell ()

@property (nonatomic,retain) UIImageView *myImageView;

@end

@implementation ImageCell

- (instancetype)initWithFrame:(CGRect)frame {
    self = [super initWithFrame:frame];
    if (self) {
        self.myImageView = [[UIImageView alloc] initWithFrame:CGRectZero];
        [self.contentView addSubview:self.myImageView];
    }
    return self;
}

- (void)setMyImage:(UIImage *)myImage {
    if (_myImage != myImage) {
        _myImage = myImage;
        self.myImageView.image = myImage;
    }
}

//布局
- (void)applyLayoutAttributes:(UICollectionViewLayoutAttributes *)layoutAttributes {
    [super applyLayoutAttributes:layoutAttributes];
    
    self.myImageView.frame = layoutAttributes.bounds;
    
}

@end