I'm writing a demo to show user's tweets.
The question is: Every time I scroll to the bottom and then scroll back, the tweet's images and comments are reloaded, even the style became mess up. I know it something do with dequeue, I set Images(which is an array of UIImageView) to [] every time after dequeue, but it is not working. I'm confused and couldn't quite sleep....
Here is core code of my TableCell(property and Images set), which provide layout:
class WechatMomentListCell: UITableViewCell{
static let identifier = "WechatMomentListCell"
var content = UILabel()
var senderAvatar = UIImageView()
var senderNick = UILabel()
var images = [UIImageView()]
var comments = [UILabel()]
override func layoutSubviews() {
//there is part of Image set and comments
if images.count != 0 {
switch images.count{
case 1:
contentView.addSubview(images[0])
images[0].snp.makeConstraints{ (make) in
make.leading.equalTo(senderNick.snp.leading)
make.top.equalTo(content.snp.bottom)
make.width.equalTo(180)
make.height.equalTo(180)
}
default:
for index in 0...images.count-1 {
contentView.addSubview(images[index])
images[index].snp.makeConstraints{ (make) in
make.leading.equalTo(senderNick.snp.leading).inset(((index-1)%3)*109)
make.top.equalTo(content.snp.bottom).offset(((index-1)/3)*109)
make.width.equalTo(90)
make.height.equalTo(90)
}
}
}
}
if comments.count != 0, comments.count != 1 {
for index in 1...comments.count-1 {
comments[index].backgroundColor = UIColor.gray
contentView.addSubview(comments[index])
comments[index].snp.makeConstraints{(make) in
make.leading.equalTo(senderNick)
make.bottom.equalToSuperview().inset(index*20)
make.width.equalTo(318)
make.height.equalTo(20)
}
}
}
}
Here is my ViewController, which provide datasource:
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
guard let tweetCell = tableView.dequeueReusableCell(withIdentifier: WechatMomentListCell.identifier, for: indexPath) as? WechatMomentListCell else {
fatalError("there is no WechatMomentList")
}
let tweet = viewModel.tweetList?[indexPath.row]
for i in tweet?.images ?? [] {
let flagImage = UIImageView()
flagImage.sd_setImage(with: URL(string: i.url))
tweetCell.images.append(flagImage)
}
for i in tweet?.comments ?? [] {
let flagComment = UILabel()
flagComment.text = "\(i.sender.nick) : \(i.content)"
tweetCell.comments.append(flagComment)
}
return tweetCell
}
The Images GET request has been define at ViewModel using Alamofire.
The firsttime is correct. However, If I scroll the screen, the comments will load again and images were mess up like this.
I found the problem in your tableview cell. in cell you have two variables like this.
var images = [UIImageView()]
var comments = [UILabel()]
Every time you using this cell images and comments are getting appended. make sure you reset these arrays every time you use this cell. like setting theme empty at initialization.