我如何得到删除按钮显示时,在一个UITableViewCell滑动?该事件永远不会引发,删除按钮也永远不会出现。


当前回答

如果你采用可变数据源,你必须将委托回调移动到UITableViewDiffableDataSource子类。例如:

class DataSource: UITableViewDiffableDataSource<SectionType, ItemType> {

    override func tableView(_ tableView: UITableView, canEditRowAt indexPath: IndexPath) -> Bool {
        return true
    }

    override func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCell.EditingStyle, forRowAt indexPath: IndexPath) {
        if editingStyle == .delete {
            if let identifierToDelete = itemIdentifier(for: indexPath) {
                var snapshot = self.snapshot()
                snapshot.deleteItems([identifierToDelete])
                apply(snapshot)
            }
        }
    }
}

其他回答

在iOS 8和Swift 2.0中,请尝试这个,

override func tableView(tableView: UITableView, canEditRowAtIndexPath indexPath: NSIndexPath) -> Bool {
   // let the controller to know that able to edit tableView's row 
   return true
}

override func tableView(tableView: UITableView, commitEdittingStyle editingStyle UITableViewCellEditingStyle, forRowAtIndexPath indexPath: NSIndexPath)  {
   // if you want to apply with iOS 8 or earlier version you must add this function too. (just left in blank code)
}

override func tableView(tableView: UITableView, editActionsForRowAtIndexPath indexPath: NSIndexPath) -> [UITableViewRowAction]?  {
   // add the action button you want to show when swiping on tableView's cell , in this case add the delete button.
   let deleteAction = UITableViewRowAction(style: .Default, title: "Delete", handler: { (action , indexPath) -> Void in

   // Your delete code here.....
   .........
   .........
   })

   // You can set its properties like normal button
   deleteAction.backgroundColor = UIColor.redColor()

   return [deleteAction]
}

对于swift4代码,首先启用编辑:

func tableView(_ tableView: UITableView, canEditRowAt indexPath: IndexPath) -> Bool {
    return true
}

然后你添加删除操作到编辑委托:

func tableView(_ tableView: UITableView, editActionsForRowAt indexPath: IndexPath) -> [UITableViewRowAction]? {
    let action = UITableViewRowAction(style: .destructive, title: "Delete") { (_, index) in
        // delete model object at the index
        self.models[index.row]
        // then delete the cell
        tableView.beginUpdates()
        tableView.deleteRows(at: [index], with: .automatic)
        tableView.endUpdates()

    }
    return [action]
}

这段代码展示了如何实现删除。

#pragma mark - UITableViewDataSource

// Swipe to delete.
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
    if (editingStyle == UITableViewCellEditingStyleDelete) {
        [_chats removeObjectAtIndex:indexPath.row];
        [tableView deleteRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationAutomatic];
    }
}

可选地,在初始化覆盖中,添加下面的行来显示Edit按钮项:

self.navigationItem.leftBarButtonItem = self.editButtonItem;

斯威夫特4、5

要在滑动中删除单元格,UITableView有两个内置的方法。把这个方法写在TableView dataSource扩展中。

func tableView(_ tableView: UITableView, trailingSwipeActionsConfigurationForRowAt indexPath: IndexPath) -> UISwipeActionsConfiguration? {
  let delete = deleteProperty(at: indexPath)
  return UISwipeActionsConfiguration(actions: [delete])
}

// Declare this method in UIViewController Main and modify according to your need

func deleteProperty(at indexpath: IndexPath) -> UIContextualAction {
  let action = UIContextualAction(style: .destructive, title: "Delete") { (action, view, completon) in
    self.yourArray.remove(at: indexpath) // Removing from array at selected index

    completon(true)
    action.backgroundColor = .red //cell background color
  }
  return action
}

@Kurbz的回答很棒,但我想留下这张纸条,希望这个答案可以节省人们一些时间。

我的控制器中偶尔会出现这些线条,它们会导致滑动功能无法工作。

- (UITableViewCellEditingStyle)tableView:(UITableView *)tableView editingStyleForRowAtIndexPath:(NSIndexPath *)indexPath{
    return UITableViewCellEditingStyleNone; 
}

如果你使用UITableViewCellEditingStyleInsert或UITableViewCellEditingStyleNone作为编辑样式,那么滑动功能就不起作用了。你只能使用UITableViewCellEditingStyleDelete,这是默认的样式。