swift - 如何从messageKit中的头像中删除缩进？

Question

我从聊天中删除了头像，我可以移动消息本身，但我无法移动消息的日期。怎么做？

还有一个问题：我在每四条消息之后写一个消息日期。如何只在第二天开始时才写时间？

屏幕上是发生的事情的一个例子。

class ChatsViewController: MessagesViewController {
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        if let layout = messagesCollectionView.collectionViewLayout as? MessagesCollectionViewFlowLayout {
            layout.textMessageSizeCalculator.outgoingAvatarSize = .zero
            layout.textMessageSizeCalculator.incomingAvatarSize = .zero
            layout.photoMessageSizeCalculator.outgoingAvatarSize = .zero
            layout.photoMessageSizeCalculator.incomingAvatarSize = .zero
            layout.attributedTextMessageSizeCalculator.incomingAvatarSize = .zero
            layout.attributedTextMessageSizeCalculator.outgoingAvatarSize = .zero
            layout.attributedTextMessageSizeCalculator.avatarLeadingTrailingPadding = .zero
        }
    }
}

// MARK: - MessagesDataSource
extension ChatsViewController: MessagesDataSource {
    
    func cellTopLabelAttributedText(for message: MessageType, at indexPath: IndexPath) -> NSAttributedString? {
        if indexPath.item % 4 == 0 {
            return NSAttributedString(
                string: MessageKitDateFormatter.shared.string(from: message.sentDate),
                attributes: [
                    NSAttributedString.Key.font: UIFont.boldSystemFont(ofSize: 10),
                    NSAttributedString.Key.foregroundColor: #colorLiteral(red: 0.1176470588, green: 0.4470588235, blue: 0.8, alpha: 1)])
        } else {
            return nil
        }
    }
    
    func messageBottomLabelAttributedText(for message: MessageType, at indexPath: IndexPath) -> NSAttributedString? {
        
        return NSAttributedString(string: MessageKitDateFormatter.shared.string(from: message.sentDate), attributes: [NSAttributedString.Key.font: UIFont.preferredFont(forTextStyle: .caption1)])
    }
    
}

// MARK: - MessagesLayoutDelegate
extension ChatsViewController: MessagesLayoutDelegate {
    
    func footerViewSize(for section: Int, in messagesCollectionView: MessagesCollectionView) -> CGSize {
        return CGSize(width: 0, height: 8)
    }
    
    func cellTopLabelHeight(for message: MessageType, at indexPath: IndexPath, in messagesCollectionView: MessagesCollectionView) -> CGFloat {
        if (indexPath.item) % 4 == 0 {
            return 30
        } else {
            return 0
        }
    }
    
    func messageBottomLabelHeight(for message: MessageType, at indexPath: IndexPath, in messagesCollectionView: MessagesCollectionView) -> CGFloat {
        return 16
    }
}

// MARK: - MessagesDisplayDelegate
extension ChatsViewController: MessagesDisplayDelegate {
    
    func configureAvatarView(_ avatarView: AvatarView, for message: MessageType, at indexPath: IndexPath, in messagesCollectionView: MessagesCollectionView) {
        avatarView.isHidden = true
    }
    
    func avatarSize(for message: MessageType, at indexPath: IndexPath, in messagesCollectionView: MessagesCollectionView) -> CGSize {
        return .zero
    }
    
    func messageStyle(for message: MessageType, at indexPath: IndexPath, in messagesCollectionView: MessagesCollectionView) -> MessageStyle {
        return .bubble
    }
}

Answer 1

您可以使用流布局上的setMessageIncomingMessageBottomLabelAlignment和setMessageOutgoingMessageBottomLabelAlignment方法来调整底部标签对齐方式，如下所示：

        messagesCollectionView.messagesCollectionViewFlowLayout.setMessageIncomingMessageBottomLabelAlignment(LabelAlignment(textAlignment: .left, textInsets: .zero))
        messagesCollectionView.messagesCollectionViewFlowLayout.setMessageOutgoingMessageBottomLabelAlignment(LabelAlignment(textAlignment: .right, textInsets: .zero))

要回答您的第二个问题，您可以在类var lastDisplayedSentDate: Date?和cellTopLabelAttributedText方法中保留一个变量，检查 lastDisplayedSentDate 是否与当前消息nil在同一天，如果它们在同一天则返回，否则返回日期字符串并更新lastDisplayedSentDate变量：

        if let lastDisplayedSentDate = lastDisplayedSentDate, Calendar.current.isDate(lastDisplayedSentDate, inSameDayAs: message.sentDate) {
            return nil
        }
        lastDisplayedSentDate = message.sentDate
        
        return NSAttributedString(
                string: MessageKitDateFormatter.shared.string(from: message.sentDate),
                attributes: [
                    NSAttributedString.Key.font: UIFont.boldSystemFont(ofSize: 10),
                    NSAttributedString.Key.foregroundColor: #colorLiteral(red: 0.1176470588, green: 0.4470588235, blue: 0.8, alpha: 1)])

您可以在该方法中添加类似的逻辑cellTopLabelHeight。