CollectionView多个单元格选择

Question

我有一个集合视图，有两个自定义单元格，一个用于网格，一个用于列表，我希望能够触摸单元格并选择它们，如果要删除或共享它们，我现在想要的只能选择和deselct他们，生病我的代码下面的结果是当我触摸一个单元格所有单元格被选中！ 这是代码：

func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
    if isGridSelected {

        let cell:cell2_Class = collectionView.dequeueReusableCellWithReuseIdentifier("cell2", forIndexPath: indexPath) as! cell2_Class

        cell.listImage.image = imageArray[indexPath.row]

        if flag == true {
            cell.layer.borderColor = UIColor.blueColor().CGColor
            cell.layer.borderWidth = 3
            cancelButton.hidden = false
        } else {
            cell.layer.borderColor = UIColor.clearColor().CGColor
            cancelButton.hidden = true
        }
        return cell
    } else {
        let cell:PhotoCollectionCell = collectionView.dequeueReusableCellWithReuseIdentifier("cell", forIndexPath: indexPath) as! PhotoCollectionCell

        if flag == true {
            cell.layer.borderColor = UIColor.blueColor().CGColor
            cell.layer.borderWidth = 3
            cancelButton.hidden = false
        } else {
            cell.layer.borderColor = UIColor.clearColor().CGColor
            cancelButton.hidden = true
        }
        cell.imageView.image = imageArray[indexPath.row]
        cell.NameLabel.text = namelabel[indexPath.row]
        cell.ModifiedLbl.text = modfLabel[indexPath.row]

        return cell
    }
}

func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) {

    let cell = collectionView.cellForItemAtIndexPath(indexPath)

    if cell!.selected == true {
        flag = true
    } else {
        flag = false 
    }
    self.collectionView.reloadData()
}

Answer 1

在PhotoCollectionCell和cell2_Class （或在一个公共superclass ），只需覆盖此方法

- (void) setSelected:(BOOL)selected 
{ 
     if (selected) 
     {        
         self.layer.borderColor = UIColor.blueColor().CGColor
         self.layer.borderWidth = 3
     } 
     else 
     {
         self.layer.borderColor = UIColor.clearColor().CGColor
     }
}

然后，您不必处理delegate或dataSource的实际selection/highlighting 。

确保将collectionView的属性allowsSelection为YES 。

如果您想要multiple selection那么还要将allowsMultipleSelection设置为YES并在您的delegate实现以下方法

- (BOOL) collectionView:(UICollectionView *)collectionView shouldSelectItemAtIndexPath:(NSIndexPath *)indexPath
{
    if ([collectionView.indexPathsForSelectedItems containsObject: indexPath])
    {
        [collectionView deselectItemAtIndexPath: indexPath animated: YES];
        return NO;            
    }
    return YES;
}

快速解决方案

collectionViewCell子类

override var selected: Bool {
    didSet {
        self.layer.borderWidth = 3.0
        self.layer.borderColor = selected ? UIColor.blueColor().CGColor : UIColor.clearColor().CGColor
    }
}

在UICollectionViewDelegate ：

func collectionView(collectionView: UICollectionView, shouldSelectItemAt indexPath: NSIndexPath) -> Bool {
    if let selectedItems = collectionView.indexPathsForSelectedItems() {
        if selectedItems.contains(indexPath) {
            collectionView.deselectItemAtIndexPath(indexPath, animated: true)
            return false
        }
    }
    return true
}

Answer 2

基于Aerows解决方案Swift 4.2

collectionViewCell子类

override var isSelected: Bool {
        didSet {
            self.layer.borderWidth = 3.0
            self.layer.borderColor = isSelected ? UIColor.blue.cgColor : UIColor.clear.cgColor
        }
    }

在UICollectionViewDelegate

func collectionView(_ collectionView: UICollectionView, shouldDeselectItemAt indexPath: IndexPath) -> Bool {
    if let selectedItems = collectionView.indexPathsForSelectedItems {
        if selectedItems.contains(indexPath) {
            collectionView.deselectItem(at: indexPath, animated: true)
            return false
        }
    }
    return true
}

而且非常重要的是，在viewDidLoad()不要忘记允许你的collectionView多项选择

collectionView.allowsMultipleSelection = true

Apple文档 - 允许多个选择