话不多说，直接上代码，自定义cell的代码就不贴了，很简单的放了个Label，这样的写法在动态切换时存在一个问题，cell内部的label的动画无法展示，处理办法是在设置isList时，通知cell内部进行动画

//
//  ViewController.m
//  XACollectionAnimationChangeProject
//
//  Created by wj on 2019/9/10.
//  Copyright © 2019年 XA. All rights reserved.
//

#import "ViewController.h"
#import "XAGridCollectionViewCell.h"

#define XAWidth [UIScreen mainScreen].bounds.size.width
#define XAHeight [UIScreen mainScreen].bounds.size.height

@interface ViewController ()<UICollectionViewDelegate,UICollectionViewDataSource>

@property (nonatomic , retain)UICollectionView *collectionView;

/**
 多行多列式布局
 */
@property (nonatomic , retain)UICollectionViewFlowLayout *gridLayout;

/**
 多行一列式布局
 */
@property (nonatomic , retain)UICollectionViewFlowLayout *listLayout;

@property (nonatomic , assign)BOOL isList;

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    [self.view addSubview:self.collectionView];
    self.collectionView.frame = CGRectMake(0, 0, XAWidth, XAHeight);
}

#pragma mark
- (UICollectionViewFlowLayout *)listLayout {
    if (!_listLayout) {
        _listLayout = [[UICollectionViewFlowLayout alloc] init];
        _listLayout.itemSize = CGSizeMake(XAWidth, 200);
        _listLayout.minimumLineSpacing = 5;
        _listLayout.sectionInset = UIEdgeInsetsZero;
    }
    return _listLayout;
}

- (UICollectionViewFlowLayout *)gridLayout {
    if (!_gridLayout) {
        _gridLayout = [[UICollectionViewFlowLayout alloc] init];
        CGFloat itemWidth = (self.view.frame.size.width - 5) * 0.5;
        _gridLayout.itemSize = CGSizeMake(itemWidth, 300);
        _gridLayout.minimumLineSpacing = 5;
        _gridLayout.minimumInteritemSpacing = 5;
        _gridLayout.sectionInset =  UIEdgeInsetsZero;
    }
    return _gridLayout;
}

- (UICollectionView *)collectionView {
    if (!_collectionView) {
        _collectionView = [[UICollectionView alloc] initWithFrame:self.view.bounds collectionViewLayout:self.gridLayout];
        [_collectionView registerClass:[XAGridCollectionViewCell class] forCellWithReuseIdentifier:@"cell1"];
        _collectionView.backgroundColor = [UIColor grayColor];
        _collectionView.delegate = self;
        _collectionView.dataSource = self;
        if (@available(iOS 11.0, *)) {
            _collectionView.contentInsetAdjustmentBehavior = UIScrollViewContentInsetAdjustmentNever;
        }else {
            self.automaticallyAdjustsScrollViewInsets = NO;
        }
    }
    return _collectionView;
}

- (void)setIsList:(BOOL)isList {
    _isList = isList;
    if (isList) {
        [self.collectionView setCollectionViewLayout:self.listLayout animated:YES];
    }else{
        [self.collectionView setCollectionViewLayout:self.gridLayout animated:YES];
    }
    [self.collectionView reloadData];
}

- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath {
    self.isList = !self.isList;
}

- (nonnull __kindof UICollectionViewCell *)collectionView:(nonnull UICollectionView *)collectionView cellForItemAtIndexPath:(nonnull NSIndexPath *)indexPath {
    XAGridCollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"cell1" forIndexPath:indexPath];
    return cell;
}

- (NSInteger)collectionView:(nonnull UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section {
    return 12;
}

//定义每一个cell的大小

- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath {
    return ((UICollectionViewFlowLayout *)collectionViewLayout).itemSize;
}

@end