ios - 无法使用 json 数据填充 UITableview

Question

我有一个本地 json 文件(你可以找到它 here )。

我正在尝试用这个 json 填充 UITableView，然后我可以生成表格。

但我只能看到提到的标题，而看不到这些标题单元格下方的相应数据。

我将在下面发布一些代码，如果有帮助，我可以分享更多

enum ProfileViewModelItemType {
    case nameAndPicture
    case about
    case email
    case friend
    case attribute
}

protocol ProfileViewModelItem {
    var type: ProfileViewModelItemType { get }
    var rowCount: Int { get }
    var sectionTitle: String  { get }
}

extension ProfileViewModelItem {
    var rowCount: Int {
        return 1
    }
}

class ProfileViewModelNameItem: ProfileViewModelItem {
    var type: ProfileViewModelItemType {
        return .nameAndPicture
    }

    var sectionTitle: String {
        return "Main Info"
    } 
}

class ProfileViewModelNameAndPictureItem: ProfileViewModelItem {
    var type: ProfileViewModelItemType {
        return .nameAndPicture
    }

    var sectionTitle: String {
        return "Main Info"
    }

    var rowCount: Int {
        return 1
    }

    var pictureUrl: String
    var name: String

    init(name: String , pictureUrl: String) {
        self.name = name
        self.pictureUrl = pictureUrl
    }
}

class ProfileViewModelAboutItem: ProfileViewModelItem {
    var type: ProfileViewModelItemType {
        return .about
    } 

    var sectionTitle: String {
        return "About"
    }
    var rowCount: Int {
        return 1
    }

    var about: String

    init(about: String) {
        self.about = about
    }
}

class ProfileViewModelEmailItem: ProfileViewModelItem {
    var type: ProfileViewModelItemType {
        return .email
    }

    var sectionTitle: String {
        return "Email"
    }
    var rowCount: Int {
        return 1
    }
    var email: String

    init(email: String) {
        self.email = email
    }
}

class ProfileViewModelAttributeItem: ProfileViewModelItem {
    var type: ProfileViewModelItemType {
        return .attribute
    }

    var sectionTitle: String {
        return "Attributes"
    }

    var rowCount: Int {
        return attributes.count
    }

    var attributes: [Attribute]

    init(attributes: [Attribute]) {
        self.attributes = attributes
    }
}

class ProfileViewModeFriendsItem: ProfileViewModelItem {
    var type: ProfileViewModelItemType {
        return .friend
    }

    var sectionTitle: String {
        return "Friends"
    }

    var rowCount: Int {
        return friends.count
    }

    var friends: [Friend]

    init(friends: [Friend]) {
        self.friends = friends
    }
}

class ProfileViewModel: NSObject {
    var items = [ProfileViewModelItem]()

    override init() {
        super.init()
        guard let data = dataFromFile("ServerData"), let profile =  Profile(data: data) else {
            return
        }

        if let name = profile.fullName, let pictureUrl = profile.pictureUrl {
            let nameAndPictureItem = ProfileViewModelNameAndPictureItem(name: name, pictureUrl: pictureUrl)
            items.append(nameAndPictureItem)
        }

        if let about = profile.about {
            let aboutItem = ProfileViewModelAboutItem(about: about)
            items.append(aboutItem)
        }

        if let email = profile.email {
            let dobItem = ProfileViewModelEmailItem(email: email)
            items.append(dobItem)
        }

        let attributes = profile.profileAttributes
        // we only need attributes item if attributes not empty
        if !attributes.isEmpty {
             let attributesItem = ProfileViewModelAttributeItem(attributes: attributes)
            items.append(attributesItem)
        }

        let friends = profile.friends
        // we only need friends item if friends not empty
        if !profile.friends.isEmpty {
            let friendsItem = ProfileViewModeFriendsItem(friends: friends)
             items.append(friendsItem)
        }
    }
}

extension ProfileViewModel:UITableViewDataSource {


    func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
        return items[section].sectionTitle
    }

    func numberOfSections(in tableView: UITableView) -> Int {
        return items.count
    }

    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return items[section].rowCount
    }

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let item = items[indexPath.section]
        switch item.type {
        case .nameAndPicture:
            if let cell = tableView.dequeueReusableCell(withIdentifier: NameAndPictureCell.identifier, for: indexPath) as? NameAndPictureCell {
                cell.item = item
                return cell
            }
        case .about:
            if let cell = tableView.dequeueReusableCell(withIdentifier: AboutCell.identifier, for: indexPath) as? AboutCell {
                cell.item = item
               return cell
            }
        case .email:
            if let cell = tableView.dequeueReusableCell(withIdentifier: EmailCell.identifier, for: indexPath) as? EmailCell {
                cell.item = item
                return cell
            }
        case .friend:
            if let item = item as? ProfileViewModeFriendsItem, let cell = tableView.dequeueReusableCell(withIdentifier: FriendCell.identifier, for: indexPath) as? FriendCell {
                let friend = item.friends[indexPath.row]
                cell.item = friend
                return cell
            }
        case .attribute:
            if let item = item as? ProfileViewModelAttributeItem, let cell = tableView.dequeueReusableCell(withIdentifier: AttributesCell.identifier, for: indexPath) as? AttributesCell {
                cell.item = item.attributes[indexPath.row]
               return cell
            }
        }

        // return the default cell if none of above succeed
        return UITableViewCell()
    }
}


public func dataFromFile(_ filename: String) -> Data? {
    @objc class TestClass: NSObject { }

    let bundle = Bundle(for: TestClass.self)
    if let path = bundle.path(forResource: filename, ofType: "json") {
        return (try? Data(contentsOf: URL(fileURLWithPath: path)))
    }
    return nil
}

class Profile {
    var fullName: String?
    var pictureUrl: String?
    var email: String?
    var about: String?
    var friends = [Friend]()
    var profileAttributes = [Attribute]()

    init?(data: Data) {
        do {
             if let json = try JSONSerialization.jsonObject(with: data) as? [String: Any],
                let body = json["data"] as? [String: Any] {
                self.fullName = body["fullName"] as? String
                self.pictureUrl = body["pictureUrl"] as? String
                self.about = body["about"] as? String
                self.email = body["email"] as? String

                if let friends = body["friends"] as? [[String: Any]] {
                    self.friends = friends.map { Friend(json: $0) }
                }

                if let profileAttributes = body["profileAttributes"] as? [[String: Any]] {
                    self.profileAttributes = profileAttributes.map { Attribute(json: $0) }
                }
            }
        } catch {
            print("Error deserializing JSON: \(error)")
            return nil
        }
    }
}

class Friend {
    var name: String?
    var pictureUrl: String?

    init(json: [String: Any]) {
        self.name = json["name"] as? String
        self.pictureUrl = json["pictureUrl"] as? String
    }
}

class Attribute {
    var key: String?
    var value: String?
    init(json: [String: Any]) {
        self.key = json["key"] as? String
        self.value = json["value"] as? String
    }
 }

表格 View 不仅应该有 friend 的名字，还应该有 Assets 中的图像。

我还为所有不同类型的单元格定义了自定义类，并将它们出列并注册

已经看了一个星期了，但仍然没有，任何帮助将不胜感激

我还提供了框架并将所有标签、图像等作为 subview 添加到 TableView 中，但没有成功

Answer 1

我有点难以理解。首先，“我还提供了框架并将所有标签、图像等作为 subview 添加到 TableView 中”听起来是错误的。您永远不需要在 UITableView 上调用 addSubview(...)。您可以通过 tableCell.contentView.addSubview(...) 将 UI 元素添加到 UITableViewCell，但即便如此，您最好使用自动布局在界面生成器中设计表格 View 单元格。现在设置框架几乎没用了，因为自动布局已经永远存在了。设置实际帧的唯一位置是在 layoutSubviews()

其次，它不显示是不是因为您将 rowHeight 设为常量而不是 UITableView.automaticDimension？也许您将单元格设计为特定高度，但您还没有告诉表格 View 它们有那个高度？我建议使用谷歌搜索“使用自动布局调整表格单元格大小”或使用表格 View 委托(delegate)方法 ...heightForRowAt indexPath: ...

最后，查看您的代码，我建议您对 JSON 解析方法进行现代化改造:

类似于 this ，或者只是谷歌“JSON and Codable swift”