集合视图在滚动时更改选定的单元格

Question

我正在尝试选择一个单元格UICollectionView,它被选中,但在向下滚动时,它选择底部的其他单元格并向上滚动显示其他一些要选择的单元格.

以下是我正在使用的代码 didSelectItemAtIndexPath

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

    cell = (CustomCollectionCell *)[collectionView cellForItemAtIndexPath:newIndex];

    NSString *strId = [[masterArray valueForKey:@"id"]objectAtIndex:indexPath.row];


    NSString *tempIndexRow = [NSString stringWithFormat:@"%ld",(long)indexPath.row];

    NSLog(@"%@, %@,%d ,%@, %d", strId,tempIndexRow,cell.imageView.tag,[boolArray objectAtIndex:indexPath.row],indexPath.row);

    if (strId && [[boolArray objectAtIndex:indexPath.row] isEqualToString:@"False"] && cell.imageView.tag == indexPath.row) {

        cell.selectedImage.image = [UIImage imageNamed:@"select.png"];

        [boolArray replaceObjectAtIndex:indexPath.row withObject:@"True"];
    }
    else{
        cell.selectedImage.image = Nil;

        [boolArray replaceObjectAtIndex:indexPath.row withObject:@"False"];
    }
}

这是我第一次选择的

这是我向下滚动时得到的结果

谢谢

Answer 1

您需要将所选项目索引存储设置为一个数组,并 cellForRowIndex使用indexPath.row检查此数组索引,如下所示: -

selectedCellsArray 在ViewDIdLoad方法中分配此数组

- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath
{
     cell = (CustomCollectionCell *)[collectionView cellForItemAtIndexPath:newIndex];
     if ( [selectedCellsArray containsObject:[NSString stringWithFormat:@"%d",indexPath.row]]  )
            {
                [selectedCellsArray removeObject:[NSString stringWithFormat:@"%d",indexPath.row]];
                cell.selectedImage.image = Nil;


            }
            else
            {
                [selectedCellsArray addObject:[NSString stringWithFormat:@"%d",indexPath.row]];
                cell.selectedImage.image = [UIImage imageNamed:@"select.png"];
            }
}

和

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
        NSNumber *rowNsNum = [NSNumber numberWithUnsignedInt:indexPath.row];
        if ( [selectedCellsArray containsObject:[NSString stringWithFormat:@"%@",rowNsNum]]  )
        {
           cell.selectedImage.image = [UIImage imageNamed:@"select.png"];


        }
        else
        {
            cell.selectedImage.image = Nil;
        }
}