如何从集合视图中删除多个选定的单元格？ （迅速）

Question

在集合视图中，我所有的单元格中都有5个数组。

如何从集合视图中删除多个选定的单元格？

var _selectedCells : NSMutableArray = []

删除按钮

@IBAction func DeleteButton(_ sender: UIBarButtonItem) {
       // How delete multiple selected cells from collection view
}

添加单元格索引

func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
     if self.EditToolBar.isHidden == true {
          self.performSegue(withIdentifier: "DetailVC", sender: indexPath.item)
     } else {
          print("EditMode")
          _selectedCells.add(indexPath)
          print("selectedCells - \(_selectedCells)")
     }
}

删除单元格索引

func collectionView(_ collectionView: UICollectionView, didDeselectItemAt indexPath: IndexPath) {
     if self.EditToolBar.isHidden == true {
     } else {
          print("EditMode")
          _selectedCells.remove(indexPath)
          print("unselectedCells - \(_selectedCells)")
     }
}

崩溃

***由于未捕获的异常'NSInternalInconsistencyException'而终止应用程序，原因：'无效更新：第0部分中的项目数无效。更新（5）后现有部分中包含的项目数必须等于更新前该部分中包含的项目数（5），正负从该部分中插入或删除的项目数（已插入0，已删除2），正负移动到该部分或从该部分移出的项目数（ 0移入，0移出）。'

Answer 1

var _selectedCells = [IndexPath]()

添加单元格索引

func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
     if self.EditToolBar.isHidden == true {
          self.performSegue(withIdentifier: "DetailVC", sender: indexPath.item)
     } else {
          print("EditMode")
         if !(_selectedCells.contains(indexPath)) {
              _selectedCells.add(indexPath)
              print("selectedCells - \(_selectedCells)")
         }

     }
}

删除细胞索引

func collectionView(_ collectionView: UICollectionView, didDeselectItemAt indexPath: IndexPath) {
     if self.EditToolBar.isHidden == true {
     } else {
          print("EditMode")

        if let index = _selectedCells.index(where: { $0 == indexPath }) {
       _selectedCells.remove(at: index)
        print("unselectedCells - \(_selectedCells)")

         }   
     }
}

删除按钮动作

@IBAction func DeleteButton(_ sender: UIBarButtonItem) {
       // Two Things To make sure of 
       // 1. Never call reloadData() right after insert/move/deleteRows..., the insert/move/delete operation reorders the table and does the animation
       // 2. Call insert/move/deleteRows... always after changing the data source array.


       // remove the data from data Source Array you passed ,of selected cells you're trying to delete .

     self.collectionView.performBatchUpdates({
         self.collectionView.deleteItems(at indexPaths: _selectedCells)
     }){
              // optional closure
            print(“finished deleting cell”)
      }



}

Answer 2

您不仅可以从集合的数据源中删除项目，还必须告诉集合视图这些项目已被删除。为此，请使用deleteItems(at indexPaths: [IndexPath])。如该方法的文档中所述，如果您要一次全部进行多项更改，例如也可以从performBatchUpdates(...)调用它。如果您要同时添加和删除项目。