ios - UICollectionView reloadData 有效，但 reloadItemsAtindexPaths 无效

Question

我尝试了非常简单的事情:在按下按钮时在 UICollectionViewCell 的 imageView 上添加图像。 (实际上，CollectionViewCell - 是带有 UIImageView IBOutlet 的自定义单元格)

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {
    CollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:reuseIdentifier forIndexPath:indexPath];
    self.cell=cell;
    return cell;
}

- (IBAction)actionAddImage:(UIBarButtonItem *)sender {
    UIImage* image=[UIImage imageNamed:@"1.jpg"];
   self.cell.imageView.image=image;
   NSIndexPath* path= [self.collectionView indexPathForCell:self.cell];
   [self.collectionView reloadItemsAtIndexPaths:@[path]];
}

只有一个单元格。并且在第一个按钮按下时没有任何反应，在第二个按钮上 - 图像出现。我输入了 NSLog，然后显示了

CollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:reuseIdentifier forIndexPath:indexPath];

返回新单元格而不是现有单元格。虽然 indexPath 是强 (section=0, row=0)，即只有一个细胞。然而，reloadData 工作完美，当然没有动画。

- (IBAction)actionAddImage:(UIBarButtonItem *)sender {
    UIImage* image=[UIImage imageNamed:@"1.jpg"];
   self.cell.imageView.image=image;
   [self.collectionView reloadData];
}

Answer 1

_array =[NSMutableArray arrayWithObjects:@{@"option":[NSNumber numberWithBool:NO]},@{@"option":[NSNumber numberWithBool:NO]},@{@"option":[NSNumber numberWithBool:NO]},@{@"option":[NSNumber numberWithBool:NO]}, nil];

- (__kindof UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
    questionImageCollectionViewCell * cell=[self.questionCollectionView dequeueReusableCellWithReuseIdentifier:@"coustomCell" forIndexPath:indexPath];
    cell.optionImageView.image=[UIImage imageNamed:[_optionImageArr objectAtIndex:indexPath.item]];


    NSDictionary *dic = self.array[indexPath.row];

    if ([dic[@"option"] boolValue]) {
        [cell.rightTickImg setHidden:NO];
    }else{
      [cell.rightTickImg setHidden:YES];

    }
   // [cell.rightTickImg setHidden:YES];
    return cell;


}


- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath
{

        //[self.array removeObjectAtIndex:indexPath.row];
    NSDictionary *dic = @{@"option":[NSNumber numberWithBool:YES]};
    [self.array insertObject:dic atIndex:indexPath.row];

    [collectionView reloadItemsAtIndexPaths:@[indexPath]];

}