Ios 除非缓存图像，否则TableView单元格格式不正确

我的tableview有一个问题，在缓存图像之前，单元格的方向不正确，只有当我返回页面并缓存图像时，单元格的方向才正确。这是我所说的一个例子，第一个图像是我第一次进入页面时的图像，我有一个函数将图像存储在imagecache中，第二个图像是当我在其他地方导航后返回该页面时的图像被缓存

格式不正确：

格式正确：

我知道这是一个非常微妙的区别 从外表看 但我很想弄明白这一点，明白为什么会发生这种情况

我的单元格恒定高度为85，以下是相关代码：

func tableView（tableView:UITableView，cellForRowAt indexath:indexPath）->UITableViewCell{
//关于这一点，索引部分我遗漏了dw
让cell=discountTableView.dequeueReusableCell（标识符：self.discountCellId，for:indexath）作为！DiscountCell
cell.textLabel？.text=折扣.retailerName
cell.detailTextLabel？.text=discount.matchedFirstName+“”+discount.matchedLastName
cell.profileImageView.image=UIImage.gif（名称：“imageLoading”）！
grabImageWithCache（折扣.retailerImageLink）{（profilePic）在中
cell.profileImageView.image=profilePic
}
//添加第二个图像
cell.matchImageView.image=UIImage.gif（名称：“imageLoading”）！
grabImageWithCache（discount.matchedProfileImage）{（matchProfilepic）在中
cell.matchImageView.image=matchProfilepic
}
//声明单元格没有选择样式（避免灰色高亮显示）
cell.selectionStyle=.none
//设置单元格曲率的格式
cell.layer.cornerRadius=38
返回单元
}

**我很好奇为什么缓存图像时单元格的高度会发生变化，因为高度设置为常量，所以我不知道为什么会发生变化。当我打印单元格的高度时，它说两次都是85

UITableViewCell类：

类折扣单元格：UITableViewCell{
覆盖func布局子视图（）{
super.layoutSubviews（）
//单元格之间的垂直间距
让padding=UIEdgeInsets（顶部：0，左侧：0，底部：7，右侧：0）
bounds=bounds.inset（by:padding）
textlab？.frame=CGRect（x:120，y:textlab！.frame.origin.y-10，宽度：textlab！.frame.width，高度：textlab！.frame.height）
detailTextLabel？.frame=CGRect（x:120，y:detailTextLabel！.frame.origin.y，宽度：detailTextLabel！.frame.width，高度：detailTextLabel！.frame.height）
//单元格间距
让边距=UIEDGEINSET（顶部：0，左侧：0，底部：85，右侧：0）
contentView.frame=contentView.frame.inset（by:margins）
}
//设置占位符imageview
让profileImageView:UIImageView={
让imageView=UIImageView（）
imageView.image=UIImage（名为：“失败”）
imageView.TranslatesAutoResizezingMaskintoConstraints=false
imageView.layer.cornerRadius=35
imageView.layer.masksToBounds=true
imageView.contentMode=.ScaleSpectFill
imageView.clipsToBounds=true
imageView.layer.borderWidth=2
imageView.layer.borderColor=#colorLiteral（红色：0.9725490196，绿色：0.9725490196，蓝色：0.9725490196，alpha:1）
返回图像视图
}()
//匹配的占位符图像视图
让matchImageView:UIImageView={
让imageView=UIImageView（）
imageView.image=UIImage（名为：“失败”）
imageView.TranslatesAutoResizezingMaskintoConstraints=false
imageView.layer.cornerRadius=35
imageView.layer.masksToBounds=true
imageView.contentMode=.ScaleSpectFill
imageView.clipsToBounds=true
返回图像视图
}()
重写init（样式：UITableViewCell.CellStyle，reuseIdentifier:String？）{
super.init（样式：。副标题，reuseIdentifier:reuseIdentifier）
添加子视图（匹配图像视图）
添加子视图（profileImageView）
//设置剖面Pic锚固件
profileImageView.leftAnchor.constraint（equalTo:self.leftAnchor，常量：5）。isActive=true
profileImageView.centerYAnchor.constraint（等式：self.centerYAnchor）.isActive=true
profileImageView.widthAnchor.constraint（equalToConstant:70）.isActive=true
profileImageView.heightAnchor.constraint（equalToConstant:70）.isActive=true
//设置火柴锚
matchImageView.centerYAnchor.constraint（等式：self.centerYAnchor）.isActive=true
matchImageView.widthAnchor.constraint（equalToConstant:70）.isActive=true
matchImageView.heightAnchor.constraint（equalToConstant:70）.isActive=true
matchImageView.leftAnchor.constraint（equalTo:profileImageView.leftAnchor，常量：35）。isActive=true
}
必需初始化？（编码器：NSCoder）{
fatalError（“初始化（编码者：）尚未实现”）
}
}

我相信我已经缩小了这个问题的范围，我注意到两次单元格之间的间距都不一致，所以我认为问题在于这些代码行

//单元格之间的垂直间距
让padding=UIEdgeInsets（顶部：0，左侧：0，底部：7，右侧：0）
bounds=bounds.inset（by:padding）

---

我不知道该怎么做，因为我看了一些教程说要更改contentviews插图，但当我这样做时，它没有任何效果，我看到一些东西说iOS 11改变了你这样做的方式，但还没有找到如何真正着手解决这个问题。

你的细胞是一个药丸形状，这意味着您可以通过执行

cell.layer.cornerRadius=cell.frame.height/2

来实现相同的效果。接下来，您应该对

profileIm使用顶部和底部约束
class RoundImageView: UIImageView {
    override func layoutSubviews() {
        layer.cornerRadius = bounds.size.height * 0.5
    }
}
class RoundEndView: UIView {
    override func layoutSubviews() {
        layer.cornerRadius = bounds.size.height * 0.5
    }
}

class RoundImageView: UIImageView {
    override func layoutSubviews() {
        layer.cornerRadius = bounds.size.height * 0.5
    }
}
class RoundEndView: UIView {
    override func layoutSubviews() {
        layer.cornerRadius = bounds.size.height * 0.5
    }
}

class DiscountCell: UITableViewCell {
    
    // "Holder" view... contains all other UI elements
    // use RoundEndView so it handles the corner radius by itself
    let holderView: RoundEndView = {
        let v = RoundEndView()
        v.translatesAutoresizingMaskIntoConstraints = false
        v.backgroundColor = .white
        return v
    }()
    
    //sets a placeholder imageview
    // use RoundImageView so it handles the corner radius by itself
    let profileImageView: RoundImageView = {
        let imageView = RoundImageView()
        imageView.image = UIImage(named: "failed")
        imageView.translatesAutoresizingMaskIntoConstraints = false
        imageView.layer.masksToBounds = true
        imageView.contentMode = .scaleAspectFill
        imageView.clipsToBounds = true
        imageView.layer.borderWidth = 2
        imageView.layer.borderColor = #colorLiteral(red: 0.9725490196, green: 0.9725490196, blue: 0.9725490196, alpha: 1)
        return imageView
    }()
    
    //PlaceHolder imageview for match
    // use RoundImageView so it handles the corner radius by itself
    let matchImageView: RoundImageView = {
        let imageView = RoundImageView()
        imageView.image = UIImage(named: "failed")
        imageView.translatesAutoresizingMaskIntoConstraints = false
        imageView.layer.masksToBounds = true
        imageView.contentMode = .scaleAspectFill
        imageView.clipsToBounds = true
        return imageView
    }()
    
    let mainLabel: UILabel = {
        let v = UILabel()
        v.translatesAutoresizingMaskIntoConstraints = false
        v.font = UIFont.systemFont(ofSize: 17.0, weight: .regular)
        return v
    }()
    
    let subLabel: UILabel = {
        let v = UILabel()
        v.translatesAutoresizingMaskIntoConstraints = false
        v.font = UIFont.systemFont(ofSize: 14.0, weight: .regular)
        return v
    }()
    
    override init(style: UITableViewCell.CellStyle, reuseIdentifier: String?) {
        super.init(style: .subtitle, reuseIdentifier: reuseIdentifier)
        commonInit()
    }
    
    required init?(coder: NSCoder) {
        super.init(coder: coder)
        commonInit()
    }
    
    func commonInit() -> Void {
        
        backgroundColor = .clear
        
        contentView.addSubview(holderView)
        
        holderView.addSubview(matchImageView)
        holderView.addSubview(profileImageView)
        holderView.addSubview(mainLabel)
        holderView.addSubview(subLabel)
        
        NSLayoutConstraint.activate([

            // holder view constraints Top 5 pts from contentView Top
            holderView.topAnchor.constraint(equalTo: contentView.topAnchor, constant: 5.0),
            // Leading 12 pts from contentView Leading
            holderView.leadingAnchor.constraint(equalTo: contentView.leadingAnchor, constant: 12.0),
            // Trailing 5 pts from contentView Trailing
            holderView.trailingAnchor.constraint(equalTo: contentView.trailingAnchor, constant: -5.0),
            // 5 pts from contentView Bottom (use lessThanOrEqualTo to avoid auto-layout warnings)
            holderView.bottomAnchor.constraint(lessThanOrEqualTo: contentView.bottomAnchor, constant: -5.0),

            //Setting Profile Pic anchors - Top and Leading 5 pts from Top and Leading of Holder view
            profileImageView.topAnchor.constraint(equalTo: holderView.topAnchor, constant: 5),
            profileImageView.leadingAnchor.constraint(equalTo: holderView.leadingAnchor, constant: 5),
            // Botom 5 pts from contentView Bottom - this will determine the height of the Holder view
            profileImageView.bottomAnchor.constraint(equalTo: holderView.bottomAnchor, constant: -5),
            // width 70 pts, height equal to width (keeps it "round")
            profileImageView.widthAnchor.constraint(equalToConstant: 70.0),
            profileImageView.heightAnchor.constraint(equalTo: profileImageView.widthAnchor),
        
            //Setting Match Pic Anchors - 35 pts from Profile Leading, centerY to Profile
            matchImageView.leadingAnchor.constraint(equalTo: profileImageView.leadingAnchor, constant: 35),
            matchImageView.centerYAnchor.constraint(equalTo: profileImageView.centerYAnchor, constant: 0.0),
            // same width and height as Profile
            matchImageView.widthAnchor.constraint(equalTo: profileImageView.widthAnchor),
            matchImageView.heightAnchor.constraint(equalTo: profileImageView.heightAnchor),
            
            //Setting Main Label Anchors - Top equal to Top of Match image
            mainLabel.topAnchor.constraint(equalTo: matchImageView.topAnchor, constant: 0.0),
            // Leading 12 pts from Match image Trailing
            mainLabel.leadingAnchor.constraint(equalTo: matchImageView.trailingAnchor, constant: 12.0),
            // prevent Trailing from going past holder view Trailing
            mainLabel.trailingAnchor.constraint(equalTo: holderView.trailingAnchor, constant: -16.0),
            
            //Setting Sub Label Anchors - Top 8 pts from Main label Bottom
            subLabel.topAnchor.constraint(equalTo: mainLabel.bottomAnchor, constant: 8.0),
            // Leading and Trailing equal to Main label Leading / Trailing
            subLabel.leadingAnchor.constraint(equalTo: mainLabel.leadingAnchor, constant: 0.0),
            subLabel.trailingAnchor.constraint(equalTo: mainLabel.trailingAnchor, constant: 0.0),
            
        ])
        
    }
}

// example Discount object struct
struct Discount {
    var retailerName: String = ""
    var matchedFirstName: String = ""
    var matchedLastName: String = ""
    var matchedProfileImage: String = ""
    var retailerImageLink: String = ""
}

class DiscountViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {
    
    let discountTableView = UITableView()
    
    let discountCellId = "dcID"
    
    var myData: [Discount] = []
    
    override func viewDidLoad() {
        super.viewDidLoad()

        // a little sample data
        var d = Discount(retailerName: "Cup & Cone", matchedFirstName: "Kara", matchedLastName: "Tomlinson", matchedProfileImage: "pro1", retailerImageLink: "")
        myData.append(d)
        d = Discount(retailerName: "Cup & Cone", matchedFirstName: "Sophie", matchedLastName: "Turner", matchedProfileImage: "pro2", retailerImageLink: "")
        myData.append(d)
        d = Discount(retailerName: "Another Retailer", matchedFirstName: "WanaB3", matchedLastName: "Nerd", matchedProfileImage: "pro3", retailerImageLink: "")
        myData.append(d)

        
        discountTableView.translatesAutoresizingMaskIntoConstraints = false
        view.addSubview(discountTableView)
        let g = view.safeAreaLayoutGuide
        NSLayoutConstraint.activate([
            discountTableView.topAnchor.constraint(equalTo: g.topAnchor, constant: 20.0),
            discountTableView.leadingAnchor.constraint(equalTo: g.leadingAnchor, constant: 20.0),
            discountTableView.trailingAnchor.constraint(equalTo: g.trailingAnchor, constant: -20.0),
            discountTableView.bottomAnchor.constraint(equalTo: g.bottomAnchor, constant: -20.0),
        ])
        
        view.backgroundColor = UIColor(red: 1.0, green: 0.9, blue: 0.7, alpha: 1.0)
        discountTableView.backgroundColor = UIColor(red: 0.66, green: 0.66, blue: 0.9, alpha: 1.0)
        discountTableView.separatorStyle = .none

        discountTableView.delegate = self
        discountTableView.dataSource = self
        
        discountTableView.register(DiscountCell.self, forCellReuseIdentifier: discountCellId)
        
    }
    
    func numberOfSections(in tableView: UITableView) -> Int {
        return 1
    }
    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return myData.count
    }
    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        //Indexing part I left out dw about this
        
        let discount = myData[indexPath.row]
        
        let cell = discountTableView.dequeueReusableCell(withIdentifier: self.discountCellId, for: indexPath) as! DiscountCell
        
        cell.mainLabel.text = discount.retailerName
        cell.subLabel.text = discount.matchedFirstName + " " + discount.matchedLastName

        // add first image
        if let img = UIImage(named: "imageLoading") {
            cell.profileImageView.image = img
        }
        // use your custom image funcs
        //cell.profileImageView.image = UIImage.gif(name: "imageLoading")!
        //grabImageWithCache(discount.retailerImageLink) { (profilePic) in
        //  cell.profileImageView.image = profilePic
        //}

        //Adding second Image
        if let img = UIImage(named: discount.matchedProfileImage) {
            cell.matchImageView.image = img
        }
        // use your custom image funcs
        //cell.matchImageView.image = UIImage.gif(name: "imageLoading")!
        //grabImageWithCache(discount.matchedProfileImage) { (matchProfilepic) in
        //  cell.matchImageView.image = matchProfilepic
        //}
        
        //declare no selection style for cell (avoid gray highlight)
        cell.selectionStyle = .none

        return cell
    }
    
}