SwiftUI vs UIKit 对比

// SwiftUI - 用户资料卡片
import SwiftUI

struct ProfileCard: View {
    @StateObject private var viewModel = ProfileViewModel()
    @State private var isFollowing = false

    var body: some View {
        VStack(alignment: .leading, spacing: 16) {
            HStack {
                AsyncImage(url: viewModel.user.avatarURL) { image in
                    image.resizable().scaledToFill()
                } placeholder: {
                    ProgressView()
                }
                .frame(width: 64, height: 64)
                .clipShape(Circle())

                VStack(alignment: .leading) {
                    Text(viewModel.user.name)
                        .font(.headline)
                    Text(viewModel.user.title)
                        .font(.subheadline)
                        .foregroundStyle(.secondary)
                }
                Spacer()

                Button(isFollowing ? "取消关注" : "关注") {
                    withAnimation(.spring(response: 0.3)) {
                        isFollowing.toggle()
                    }
                }
                .buttonStyle(.bordered)
                .tint(isFollowing ? .gray : .blue)
            }
        }
        .padding()
        .background(.regularMaterial)
        .clipShape(RoundedRectangle(cornerRadius: 16))
    }
}

// UIKit - 用户资料卡片
import UIKit

class ProfileCardViewController: UIViewController {
    private let avatarImageView: UIImageView = {
        let iv = UIImageView()
        iv.contentMode = .scaleAspectFill
        iv.clipsToBounds = true
        iv.layer.cornerRadius = 32
        iv.translatesAutoresizingMaskIntoConstraints = false
        return iv
    }()

    private let nameLabel: UILabel = {
        let label = UILabel()
        label.font = .preferredFont(forTextStyle: .headline)
        label.translatesAutoresizingMaskIntoConstraints = false
        return label
    }()

    private lazy var followButton: UIButton = {
        var config = UIButton.Configuration.bordered()
        config.title = "关注"
        let btn = UIButton(configuration: config)
        btn.addTarget(self, action: #selector(followTapped), for: .touchUpInside)
        btn.translatesAutoresizingMaskIntoConstraints = false
        return btn
    }()

    override func viewDidLoad() {
        super.viewDidLoad()
        setupUI()
        loadUserData()
    }

    private func setupUI() {
        view.addSubview(avatarImageView)
        view.addSubview(nameLabel)
        view.addSubview(followButton)
        NSLayoutConstraint.activate([
            avatarImageView.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: 16),
            avatarImageView.centerYAnchor.constraint(equalTo: view.centerYAnchor),
            avatarImageView.widthAnchor.constraint(equalToConstant: 64),
            avatarImageView.heightAnchor.constraint(equalToConstant: 64)
        ])
    }

    @objc private func followTapped() {
        UIView.animate(withDuration: 0.3) {
            self.followButton.alpha = 0.5
        } completion: { _ in
            UIView.animate(withDuration: 0.3) { self.followButton.alpha = 1 }
        }
    }
}