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Jovins · Oct 12, 2021 · 50a9288 · 50a9288
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diff --git a/README.md b/README.md
@@ -3,3 +3,223 @@ About PDFKit learning project on iOS 11, Like iBooks.app.
 
 ## 书库
 <img src="Resources/1.png" style="width: 300px; height: 640px;" width="300" height="640"></img>&nbsp;<img src="Resources/8.png" style="width: 300px; height: 640px;" width="300" height="640"></img><br>
+
+> 两者之间的写法会有一些问题，下面在问题部分有说明。
+
+书库页面获取PDF相关数据, 可以通过KVC获取。
+
++ PDF书名
+```swift
+if let title = documentAttributes["Title"] as? String {
+    cell.title = title
+}
+```
+
++ PDF作者
+
+```swift
+if let author = documentAttributes["Author"] as? String {
+	 cell.author = author
+}
+```
+
++ 获取第一页作为封面，封面已经做了缓存
+
+```swift
+let thumbnailCache = NSCache<NSURL, UIImage>()
+private let downloadQueue = DispatchQueue(label: "com.jovins.pdfview.thumbnail")
+if let page = document.page(at: 0), let key = document.documentURL as NSURL? {     
+    cell.url = key
+    if let thumbnail = thumbnailCache.object(forKey: key) {
+        cell.image = thumbnail
+    } else {
+        downloadQueue.async {
+            let imgWidth: CGFloat = (UIScreen.main.bounds.width - 48)/2 - 24
+            let imgHeight: CGFloat = 190
+            let thumbnail = page.thumbnail(of: CGSize(width: imgWidth, height: imgHeight), for: .cropBox)
+            self.thumbnailCache.setObject(thumbnail, forKey: key)
+            if cell.url == key {
+                DispatchQueue.main.async {
+                    cell.image = thumbnail
+                }
+            }
+        }
+    }
+}
+```
+
+## PDF浏览
+
+<img src="Resources/2.png" style="width: 300px; height: 640px;" width="300" height="640"></img>&nbsp;<img src="Resources/3.png" style="width: 300px; height: 640px;" width="300" height="640"></img><br>
+<img src="Resources/4.png" style="width: 300px; height: 640px;" width="300" height="640"></img>&nbsp;<img src="Resources/5.png" style="width: 300px; height: 640px;" width="300" height="640"></img><br>
+
+图一是PDF浏览详情页
+
+```swift
+private lazy var pdfView: PDFView = {  
+    let view = PDFView()
+    view.backgroundColor = Device.bgColor
+    view.autoScales = true
+    view.displayMode = .singlePage
+    view.displayDirection = .horizontal
+    view.usePageViewController(true, withViewOptions: [UIPageViewController.OptionsKey.spineLocation: 20])
+    return view
+}()
+self.pdfView.document = self.document
+```
+
+图二是该PDF的所有页面
+
+```swift
+/// 该页面的核心代码
+if let doc = self.document, let page = doc.page(at: indexPath.item) {   
+    let pageNumber = indexPath.item
+    cell.pageNumber = pageNumber
+    let key = NSNumber(value: pageNumber)
+    if let thumbnail = self.thumbnailCache.object(forKey: key) {
+        cell.image = thumbnail
+    } else {
+        let cellSize = CGSize(width: (UIScreen.main.bounds.width - 16 * 4)/3, height: 140)
+        downloadQueue.async {
+            let thumbnail = page.thumbnail(of: cellSize, for: .cropBox)
+            self.thumbnailCache.setObject(thumbnail, forKey: key)
+            if cell.pageNumber == pageNumber {
+                DispatchQueue.main.async {
+                    cell.image = thumbnail
+                }
+            }
+        }
+    }
+}
+```
+
+图三是该PDF的目录
+
+```swift
+/// 该页面核心代码
+let outline = self.lines[indexPath.item]
+cell.titleString = outline.label
+cell.pageString = outline.destination?.page?.label
+
+var indentationLevel = -1
+var parent = outline.parent
+while let _ = parent {
+    indentationLevel += 1
+    parent = parent?.parent
+}
+cell.indentationLevel = indentationLevel
+```
+
+图四是浏览时收藏的页面。
+
+```swift
+/// 获取收藏页
+if let documentURL = self.document?.documentURL?.absoluteString, let bookmarks = UserDefaults.standard.array(forKey: documentURL) as? [Int] {
+    self.bookmarks = bookmarks
+    self.collection.reloadData()
+}
+// 显示收藏
+let pageNumber = self.bookmarks[indexPath.item]
+if let page = self.document?.page(at: pageNumber) {
+    cell.pageNumber = pageNumber
+    let key = NSNumber(value: pageNumber)
+    if let thumbnail = self.thumbnailCache.object(forKey: key) {
+        cell.image = thumbnail
+    } else {
+        let cellSize = CGSize(width: (UIScreen.main.bounds.width - 16 * 4)/3, height: 140)
+        downloadQueue.async {
+            let thumbnail = page.thumbnail(of: cellSize, for: .cropBox)
+            self.thumbnailCache.setObject(thumbnail, forKey: key)
+            if cell.pageNumber == pageNumber {
+                DispatchQueue.main.async {
+                    cell.image = thumbnail
+                }
+            }
+        }
+    }
+}
+```
+
+打印，直接调取系统方法。
+
+```swift
+let printInteractionController = UIPrintInteractionController.shared
+        printInteractionController.printingItem = self.document?.dataRepresentation()
+        printInteractionController.present(animated: true, completionHandler: nil)
+```
+
+## 浏览历史
+
+<img src="Resources/7.png" style="width: 300px; height: 640px;" width="300" height="640"></img>&nbsp;<img src="Resources/6.png" style="width: 300px; height: 640px;" width="300" height="640"></img><br>
+
+在浏览页存储历史记录
+
+
+```Swift
+private func storgeHistoryList() {
+    if let documentURL = self.document?.documentURL?.absoluteString {
+        let cache = FileManager.default.urls(for: .cachesDirectory, in: .userDomainMask)[0].absoluteString
+        let key = cache.appending("com.jovins.ibook.storgeHistory")
+        if var documentURLs = UserDefaults.standard.array(forKey: key) as? [String] {
+            if !documentURLs.contains(documentURL) {
+                // 不存在则存储
+                documentURLs.append(documentURL)
+                UserDefaults.standard.set(documentURLs, forKey: key)
+            }
+        } else {
+            // 第一次存储
+            UserDefaults.standard.set([documentURL], forKey: key)
+        }
+    }
+}
+```
+
+获取已浏览的记录
+
+```swift
+fileprivate func refreshData() {
+
+    let cache = FileManager.default.urls(for: .cachesDirectory, in: .userDomainMask)[0].absoluteString
+    let key = cache.appending("com.jovins.ibook.storgeHistory")
+    if let documentURLs = UserDefaults.standard.array(forKey: key) as? [String] {
+        var urls: [URL] = []
+        for str in documentURLs {
+            if let url = URL(string: str) {
+                urls.append(url)
+            }
+        }
+        self.documents = urls.compactMap { PDFDocument(url: $0) }
+        self.tableView.reloadData()
+    }
+}
+```
+
+## 搜索
+
+通过PDFDocument设置代理，然后调用`beginFindString`可以实现搜索功能。
+
+```swift
+func searchBar(_ searchBar: UISearchBar, textDidChange searchText: String) {
+    let searchText = searchBar.text!.trimmingCharacters(in: CharacterSet.whitespaces)
+    if searchText.count < 3 {
+        return
+    }
+    self.searchResults.removeAll()
+    self.tableView.reloadData()
+    if let document = self.document {
+        document.cancelFindString()
+        document.delegate = self
+        document.beginFindString(searchText, withOptions: .caseInsensitive)
+    }
+}
+/// 代理实现的方法，可以获取到搜索结果
+func didMatchString(_ instance: PDFSelection) {
+    self.searchResults.append(instance)
+    self.tableView.reloadData()
+}
+```
+
+## 问题
+
+在书库部分有两张列表展示页，图一搜索时会闪退，图二则不会。问题是出在图一中我已经通过`URL`获取到`PDFDocument`列表数据，而且通过KVC获取到书名和作者的相关信息展示出来。那么在搜索时则会出现内存暴增闪退(这个问题我暂时也不知道原因)。图二则是简单通过URL来展示信息，在浏览PDF时才通过`PDFDocument`获取相关数据。
+
diff --git a/Resources/.DS_Store b/Resources/.DS_Store
diff --git a/Resources/1.png b/Resources/1.png