IOS Runtime属性关联实现表格编辑文本

#import "ViewController.h"

//属性关联属于动态运行时
#import <objc/runtime.h>
//设置key
const static NSString *key=@"indexPath";

@interface ViewController ()<UICollectionViewDataSource,UICollectionViewDelegate,UICollectionViewDelegateFlowLayout,UITextViewDelegate>
{
    CGFloat _imgHeight;
    UICollectionView *_mCollectionView;
}

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    [self.view addSubview:[self createCollectionView]];
    
}

//create CollectionView
- (UICollectionView *)createCollectionView
{
//    UICollectionViewDelegateFlowLayout
    UICollectionViewFlowLayout *layout = [[UICollectionViewFlowLayout alloc] init];
    _imgHeight = (self.view.frame.size.width - 50)/4;
    layout.itemSize = CGSizeMake((self.view.frame.size.width - 50)/4, 30);
    layout.minimumLineSpacing = 10;
    layout.minimumInteritemSpacing = 10;
    layout.sectionInset = UIEdgeInsetsMake(10, 10, 10, 10);
    
    _mCollectionView = [[UICollectionView alloc] initWithFrame:self.view.bounds collectionViewLayout:layout ];
    
    _mCollectionView.delegate = self;
    _mCollectionView.dataSource = self;
    _mCollectionView.backgroundColor = [UIColor whiteColor];
    [_mCollectionView registerClass:[UICollectionViewCell class] forCellWithReuseIdentifier:@"Cell"];
    return _mCollectionView;
}

//UICollectionViewDataSource,UICollectionViewDelegate
- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView
{
    return 2;
}

- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section
{
    if (section==0) {
        return 10;
    }
    return 20;
}

- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath
{
    NSLog(@"%@",indexPath);
}
- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
    
    UICollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"Cell" forIndexPath:indexPath];
    UITextView *textView=[[UITextView alloc]initWithFrame:CGRectMake(0, 0, _imgHeight,30)];
    textView.layer.borderWidth=2;
    textView.layer.borderColor=[UIColor redColor].CGColor;
    [cell.contentView addSubview:textView];
    
    //属性关联  设置
    objc_setAssociatedObject(textView, key.UTF8String, indexPath , OBJC_ASSOCIATION_RETAIN);
    textView.delegate=self;
    
    return cell;
}

//UITextViewDelegate
- (void)textViewDidEndEditing:(UITextView *)textView
{

    //属性关联  获取
    NSIndexPath *indexPath=objc_getAssociatedObject(textView, key.UTF8String);
    NSLog(@"%@",indexPath);
    
}
- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

@end