Question

因为标题会建议我使用JSQMessagesViewController。我喜欢每个用户拥有自己的头像[UIImage]，从FirebaseDatabase中的URL获取并通过它提取它。 SDWebImage。我能够把它拿到里面;

override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
    let cell = super.collectionView(collectionView, cellForItemAt: indexPath) as! JSQMessagesCollectionViewCell

    let message = messages[indexPath.item]

    if let messageID = message.senderId {
        rootRef.child("users").child(messageID).observe(.value, with: { (snapshot) in

            if let profileURL = (snapshot.value as AnyObject!)!["profileURL"] as! String! {
                let profileNSURL: NSURL = NSURL(string: profileURL)!
                cell.avatarImageView.sd_setImage(with: profileNSURL as URL)
            }
        })
    }
            return cell
}

但是，每次发送消息并重新加载表时，图像会消失，然后重新出现，因为我假设它再次通过所有索引路径。

以下方法用于处理头像的dataSource;

override func collectionView(_ collectionView: JSQMessagesCollectionView!, avatarImageDataForItemAt indexPath: IndexPath!) -> JSQMessageAvatarImageDataSource! {
 return ???????????????????????????????????????
}

但似乎无法组织与cellForItemAt相同的逻辑？有人可以帮忙吗？......非常感谢。

更新： - ******************************************** **********************

override func collectionView(_ collectionView: JSQMessagesCollectionView!, avatarImageDataForItemAt indexPath: IndexPath!) -> JSQMessageAvatarImageDataSource! {

    let placeHolderImage = UIImage(named: "Circled User Male Filled-25")
    let avatarImage = JSQMessagesAvatarImage(avatarImage: nil, highlightedImage: nil, placeholderImage: placeHolderImage)

    let message = messages[indexPath.item]

    if let messageID = message.senderId {

        rootRef.child("users").child(messageID).observe(.value, with: { (snapshot) in

            if let profileURL = (snapshot.value as AnyObject!)!["profileURL"] as! String! {

                let profileNSURL: NSURL = NSURL(string: profileURL)!

                // download avatar image here somehow!?
                let manager: SDWebImageManager = SDWebImageManager.shared()
                manager.downloadImage(with: profileNSURL as URL!, options: [], progress: { (receivedSize: Int, actualSize: Int) in
                    print(receivedSize, actualSize)
                }, completed: { (image, error, cached, finished, url) in
                    avatarImage!.avatarImage = image
                })
            }
        })
    }

    return avatarImage
}

没有错误及其打印图像尺寸。但是图像没有从占位符图像改变！...

Answer 1

HORAY！我终于从Docs中找到了......在所有地方。

您必须按照以下方式初步设置现有头像...

所以;

let message = messages[indexPath.item]

添加以下内容。

       if avatarImage?.avatarImage == nil {
       avatarImage?.avatarImage = SDImageCache.shared().imageFromDiskCache(forKey: message.senderId)
       }

然后检查Avatars是否存在，如果没有，请去获取它们！但是将它们设置为现有头像中的密钥。例如（message.senderID）

if image != nil {
manager.imageCache.store(image, forKey: message.senderId)

DispatchQueue.main.async
{                                
avatarImage!.avatarImage = image
avatarImage!.avatarHighlightedImage = image
}

和Bam！各地的头像。希望这有助于某人！

具有SDWebImage的JSQMessagesViewController中的用户特定头像

1 个答案: