ios - 如何使用 swift 下载和共享 pdf 文件

Question

在我正在构建的应用程序中，我必须生成一个 pdf 文件，然后通过电子邮件、WhatsApp 等共享。

目前我已经按照以下代码生成pdf。

    import UIKit

    class ViewController: UIViewController {
        @IBOutlet weak var masterContainerView: UIView!
        @IBOutlet weak var pdfButton: UIButton!

        @IBAction func generatePDFtapped(_ sender: Any) {
            pdfButton.isHidden = true
            generatePDF()
            pdfButton.isHidden = false
        }

        func generatePDF() {
            let pdfWrittenPath = masterContainerView.exportAsPdfFromView()
            print("PDF written at \(pdfWrittenPath)")
        }
    }

上面的代码是 View Controller ，类文件是这样的:

    import Foundation
    import UIKit

    //to call this, use the <viewoutletname>.exportAsPdfFromView()

    extension UIView {
        // Export pdf from Save pdf in directory and return pdf file path


        func exportAsPdfFromView() -> String {
            let pdfPageFrame = self.bounds
            let pdfData = NSMutableData()
            UIGraphicsBeginPDFContextToData(pdfData, pdfPageFrame, nil)
            UIGraphicsBeginPDFPageWithInfo(pdfPageFrame, nil)
            guard let pdfContext = UIGraphicsGetCurrentContext() else { return "" }
            self.layer.render(in: pdfContext)
            UIGraphicsEndPDFContext()
            return self.saveViewPdf(data: pdfData)

        }

        // Save pdf file in document directory
        func saveViewPdf(data: NSMutableData) -> String {
            let paths = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)
            let docDirectoryPath = paths[0]
            let pdfPath = docDirectoryPath.appendingPathComponent("viewPdf.pdf")
            if data.write(to: pdfPath, atomically: true) {
                return pdfPath.path
                print("PDF written at path \(pdfPath.path)")
            } else {
                return ""
            }
        }
    }

我在互联网上找到了一个有用的示例，它准确地解释了我必须做什么。但我的问题是，EXAMPLE 开发人员正在访问公共(public) URL，而不是加载保存的 PDF 文件(已存储)。请帮我修改一下代码。

https://github.com/mansi-cherry/iOSHowTo-s/blob/master/documentInteractionDemo/documentInteractionDemo/ViewController.swift

---

expected output image 这是预期的输出，但不应获取图像文件，而应获取 pdf

Answer 1

那么您只想加载之前保存的文件？

执行相同的操作来访问文件名和路径，然后读取内容。

let paths = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)
let docDirectoryPath = paths.first
let pdfPath = docDirectoryPath.appendingPathComponent("viewPdf.pdf")

let data = Data(contentsOf: pdfPath)

完整示例:

class ViewController: UIViewController {

    let dataString = "Helloooooo world"

    override func viewDidLoad() {
        super.viewDidLoad()

        saveFile()
        readFile()
    }

    func saveFile() {
        let paths = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)
        let docDirectoryPath = paths.first
        let pdfPath = docDirectoryPath?.appendingPathComponent("test.txt")

        let data = dataString.data(using: .utf8)
        try? data?.write(to: pdfPath!)
    }

    func readFile() {
        let paths = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)
        let docDirectoryPath = paths.first
        let pdfPath = docDirectoryPath?.appendingPathComponent("test.txt")

        let data = try? Data(contentsOf: pdfPath!)
        let str = String(bytes: data!, encoding: .utf8)
        print("[DEBUG] result is \(str)")
    }
}

输出:

[DEBUG] result is Optional("Helloooooo world")