我有一个接收消息数组的方法。 它检查消息是否包含媒体项目，如果它确实包含媒体项目，则它将检查媒体是否已经缓存在设备上，如果未保存，它将下载图像并将其保存在设备上。登记/> 在每次迭代结束时，媒体项目或文本将显示在集合视图控制器中。
一切正常但是它们没有按照绝对正常的顺序添加，所以我想知道我能做些什么来克服这个问题？
This is how it should be shown
------------------------------
Text
Picture -> not cached
Text
Text
Picture -> Cached
Text
Picture -> not cached
This is how it appears
----------------------
Text
Text
Text
Text
Picture -> Cached
Picture -> not cached
Picture -> not cached
更新目前我的代码并不是很漂亮：D
func singleSBDtoJSQ(messages:[SBDBaseMessage]) {
print("sbmToJSQ")
for message in messages {
if let userMessage = message as? SBDUserMessage {
let jsqMessage = CustomJSQMessage(senderId: userMessage.sender?.userId, senderDisplayName: userMessage.sender?.nickname, date: Date(ticks: UInt64(userMessage.createdAt)), text: userMessage.message)
if userMessage.sender?.userId == self.senderId {
jsqMessage?.status = " ✓✓ "
}
jsqMessage?.sbdBaseMessage = message
self.messages.append(jsqMessage!)
} else {
let fileMessage = message as! SBDFileMessage
print("file message")
let url = URL(string: fileMessage.url)
let cacheResult = ImageCache.default.isImageCached(forKey: (url?.absoluteString)!)
if cacheResult.cached {
ImageCache.default.retrieveImage(forKey: (url?.absoluteString)!, options: nil, completionHandler: { (image, cacheType) in
if let cachedImage = image as? UIImage {
let mediaItem = JSQPhotoMediaItem()
mediaItem.image = cachedImage
let jsqMessage = CustomJSQMessage(senderId: fileMessage.sender?.userId, displayName: fileMessage.sender?.nickname, media: mediaItem)
print("Image caches")
if fileMessage.sender?.userId == self.senderId {
jsqMessage?.status = " ✓✓ "
mediaItem.appliesMediaViewMaskAsOutgoing = true
} else {
mediaItem.appliesMediaViewMaskAsOutgoing = false
}
jsqMessage?.sbdBaseMessage = message
self.messages.append(jsqMessage!)
return
} else {
return
}
})
} else {
print("image not cached")
let imageView = UIImageView()
imageView.kf.setImage(with: url, completionHandler: {
(image, error, cacheType, imageUrl) in
if error != nil {
print("error while downloading image")
return
} else {
print("image downloaded")
let mediaItem = JSQPhotoMediaItem()
mediaItem.image = image
let jsqMessage = CustomJSQMessage(senderId: fileMessage.sender?.userId, displayName: fileMessage.sender?.nickname, media: mediaItem)
if fileMessage.sender?.userId == self.senderId {
jsqMessage?.status = " ✓✓ "
mediaItem.appliesMediaViewMaskAsOutgoing = true
} else {
mediaItem.appliesMediaViewMaskAsOutgoing = false
}
jsqMessage?.sbdBaseMessage = message
self.messages.append(jsqMessage!)
}
})
}
}
}
self.finishSendingMessage(animated: true)
}