ios - 我们可以使用 Pencil Kit 在照片标记中添加文本、形状和签名吗？

Question

在我的应用程序中使用 PencelKit 标记照片时，我没有任何添加文本、形状和签名的选项。此选项在 Apple 的照片应用程序中可用。我尝试使用 CanvasView 和 PKToolPicker 的各种属性来访问它，但没有成功。

self.canvasView?.drawing = PKDrawing()
self.canvasView.allowsFingerDrawing = true
if let window = self.view.window, let toolPicker = PKToolPicker.shared(for: window) {
     toolPicker.setVisible(true, forFirstResponder: self.canvasView)
     toolPicker.addObserver(self.canvasView)
     self.canvasView.becomeFirstResponder()
}

Answer 1

我终于想通了!这是 QLPreviewController !
使用形状、箭头和签名进行编辑仅适用于 iOS13+。
首先我们需要从一个 url 读取文件，所以用 init 设置它。我以这样的东西作为基础并附加文件名，也带有文件扩展名，例如.pdf:

FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).last!

您无法将其保存在 tempDirectory 中，因为 QLPreviewViewController 需要访问权限。没有权限可能会导致如下错误:

AX Lookup problem - errorCode:1100 error:Permission denied portName:

您的 customVC 应如下所示:

import UIKit
import QuickLook
class CustomVC: UIViewController {
    var url: URL    

    init(url: URL) {
        self.url = url
    }

....func viewDidLoad() and stuff ......

    func editFile() {
        let editor = QLPreviewController()
        editor.dataSource = self
        editor.delegate = self
        editor.setEditing(true, animated: true)
        present(editor, animated: true, completion: nil)
    }
}

// Load the file in the QLPreviewController with DataSource
extension CustomVC: QLPreviewControllerDataSource {
    func numberOfPreviewItems(in controller: QLPreviewController) -> Int {
        return 1
    }
    
    func previewController(_ controller: QLPreviewController, previewItemAt index: Int) -> QLPreviewItem {
        return self.url! as QLPreviewItem
    }  
}

// Make editing available with Delegate
@available(iOS 13.0, *)
extension CustomVC: QLPreviewControllerDelegate {
    
    func previewController(_ controller: QLPreviewController, editingModeFor previewItem: QLPreviewItem) -> QLPreviewItemEditingMode {
        return .updateContents
    }
    
    func previewController(_ controller: QLPreviewController, didUpdateContentsOf previewItem: QLPreviewItem) {
        print("UPDATE")
    }
    
    func previewController(_ controller: QLPreviewController, didSaveEditedCopyOf previewItem: QLPreviewItem, at modifiedContentsURL: URL) {
        print("SAVED at \(modifiedContentsURL)")
    }
}

如果您在委托(delegate)中正确实现了这些功能，标记按钮将自动显示。
您还可以像往常一样使用额外的导航 Controller 为此 VC 添加更多 barButtonItems，例如在 editFile 函数中是这样的:

        let navController = UINavigationController(rootViewController: editor)
        let customButton = UIBarButtonItem(image: UIImage(systemName: "yourImageName"), style: .plain, target: self, action: #selector(customButtonTapped(_:)))
        let doneButton = UIBarButtonItem(barButtonSystemItem: .done, target: self, action: #selector(doneButtonTapped(_:)))

        if var items = editor.navigationItem.rightBarButtonItems {
            items.append(customButton)
            editor.navigationItem.rightBarButtonItems = items
        } else {
            editor.navigationItem.rightBarButtonItems = [customButton]
        }
        editor.navigationItem.leftBarButtonItem = doneButton
        viewController?.present(navController, animated: true, completion: nil)
        self.navigationController = navController