如何在Swift中的完成处理程序中返回布尔值

Question

我正在尝试重构我的代码，并想在中返回Bool一个closure。当我尝试它时，它说它是未使用的并且不起作用。我可以用另一种方式来做，但是我要重复不想做的代码。我该怎么办。

func tableView(_ pTableView: UITableView, canEditRowAt pIndexPath: IndexPath) -> Bool {

    // These lines are the one that work but would like to get rid of them
    if let rowConversation = self.objectAtIndexPath(pIndexPath) as? Conversation {
        if rowConversation.isGroupChat && rowConversation.expired  {
            return true
        }
    }

    self.getRowConversation(pIndexPath: pIndexPath) {
        // how to return true here
    }
    return false
}

private func getRowConversation(pIndexPath: IndexPath, completion pCompletion: () -> Void) {
    if let rowConversation = self.objectAtIndexPath(pIndexPath) as? Conversation {
        if rowConversation.isGroupChat && rowConversation.expired  {
            ConversationManager.shared.deleteConversationID(rowConversation.conversationID)
            pCompletion()
        }
    }
}

Answer 1

您可能对此考虑过度。这里不需要“关闭”；不需要“完成处理程序”。没有异步发生。只需将其getRowConversation转换为返回Bool的普通函数即可；调用它，并将结果传回给您。

private func getRowConversation(pIndexPath: IndexPath) -> Bool {
    if let rowConversation = self.objectAtIndexPath(pIndexPath) as? Conversation {
        if rowConversation.isGroupChat && rowConversation.expired  {
            ConversationManager.shared.deleteConversationID(rowConversation.conversationID)
            return true
        }
    }
    return false
}

并这样称呼它：

func tableView(_ pTableView: UITableView, canEditRowAt pIndexPath: IndexPath) -> Bool {
    return self.getRowConversation(pIndexPath: pIndexPath)
}