同步相册云盘界面并完善相关交互

suixinkan/UI/CloudDrive/CloudDrivePreviewViewController.swift

@@ -8,13 +8,17 @@ import Kingfisher
 import SnapKit
 import UIKit
 
-/// 云盘文件预览页，黑底展示图片或视频。
+/// 云盘文件预览页，严格对齐 Android 黑底预览并保留 iOS 原生视频控制层。
 final class CloudDrivePreviewViewController: BaseViewController {
     private let file: CloudFile
     private let imageView = UIImageView()
     private var playerViewController: AVPlayerViewController?
+    private var previousStandardAppearance: UINavigationBarAppearance?
+    private var previousScrollEdgeAppearance: UINavigationBarAppearance?
+    private var previousCompactAppearance: UINavigationBarAppearance?
+    private var previousTintColor: UIColor?
 
-    /// 初始化预览页。
+    /// 初始化云盘文件预览页。
     init(file: CloudFile) {
         self.file = file
         super.init(nibName: nil, bundle: nil)
@@ -25,9 +29,23 @@ final class CloudDrivePreviewViewController: BaseViewController {
         fatalError("init(coder:) has not been implemented")
     }
 
+    override var preferredStatusBarStyle: UIStatusBarStyle {
+        .lightContent
+    }
+
     override func setupNavigationBar() {
-        title = ""
-        navigationController?.navigationBar.tintColor = .white
+        navigationItem.titleView = UIView()
+        navigationItem.hidesBackButton = true
+        let backButton = UIButton(type: .system)
+        backButton.setImage(
+            UIImage(systemName: "chevron.left")?.withConfiguration(UIImage.SymbolConfiguration(pointSize: 20, weight: .medium)),
+            for: .normal
+        )
+        backButton.tintColor = .white
+        backButton.accessibilityLabel = "返回"
+        backButton.addTarget(self, action: #selector(backTapped), for: .touchUpInside)
+        backButton.snp.makeConstraints { make in make.width.height.equalTo(44) }
+        navigationItem.leftBarButtonItem = UIBarButtonItem(customView: backButton)
     }
 
     override func setupUI() {
@@ -39,37 +57,71 @@ final class CloudDrivePreviewViewController: BaseViewController {
         }
     }
 
+    override func viewWillAppear(_ animated: Bool) {
+        super.viewWillAppear(animated)
+        applyTransparentNavigationBar()
+        setNeedsStatusBarAppearanceUpdate()
+    }
+
     override func viewWillDisappear(_ animated: Bool) {
         super.viewWillDisappear(animated)
-        navigationController?.navigationBar.tintColor = AppColor.primary
+        restoreNavigationBar()
         playerViewController?.player?.pause()
     }
 
     private func setupImage() {
         imageView.contentMode = .scaleAspectFit
         imageView.backgroundColor = .black
+        imageView.accessibilityLabel = file.name
         view.addSubview(imageView)
-        imageView.snp.makeConstraints { make in
-            make.edges.equalTo(view.safeAreaLayoutGuide)
-        }
-        if let url = URL(string: file.fileUrl) {
+        imageView.snp.makeConstraints { make in make.edges.equalTo(view.safeAreaLayoutGuide) }
+        if let url = URL(string: file.fileUrl), !file.fileUrl.isEmpty {
             imageView.kf.setImage(with: url)
         }
     }
 
     private func setupVideo() {
-        guard let url = URL(string: file.fileUrl) else { return }
+        guard let url = URL(string: file.fileUrl), !file.fileUrl.isEmpty else { return }
         let player = AVPlayer(url: url)
         let controller = AVPlayerViewController()
         controller.player = player
         controller.view.backgroundColor = .black
         addChild(controller)
         view.addSubview(controller.view)
-        controller.view.snp.makeConstraints { make in
-            make.edges.equalTo(view.safeAreaLayoutGuide)
-        }
+        controller.view.snp.makeConstraints { make in make.edges.equalTo(view.safeAreaLayoutGuide) }
         controller.didMove(toParent: self)
         playerViewController = controller
         player.play()
     }
+
+    private func applyTransparentNavigationBar() {
+        guard let navigationBar = navigationController?.navigationBar else { return }
+        previousStandardAppearance = navigationBar.standardAppearance
+        previousScrollEdgeAppearance = navigationBar.scrollEdgeAppearance
+        previousCompactAppearance = navigationBar.compactAppearance
+        previousTintColor = navigationBar.tintColor
+
+        let appearance = UINavigationBarAppearance()
+        appearance.configureWithTransparentBackground()
+        appearance.backgroundColor = .clear
+        appearance.shadowColor = .clear
+        navigationBar.standardAppearance = appearance
+        navigationBar.scrollEdgeAppearance = appearance
+        navigationBar.compactAppearance = appearance
+        navigationBar.tintColor = .white
+    }
+
+    private func restoreNavigationBar() {
+        guard let navigationBar = navigationController?.navigationBar else { return }
+        if let previousStandardAppearance {
+            navigationBar.standardAppearance = previousStandardAppearance
+        }
+        navigationBar.scrollEdgeAppearance = previousScrollEdgeAppearance
+        navigationBar.compactAppearance = previousCompactAppearance
+        navigationBar.tintColor = previousTintColor
+    }
+
+    @objc private func backTapped() {
+        navigationController?.popViewController(animated: true)
+    }
 }