创建多页 PDF [英] Create PDF with multiple pages
本文介绍了创建多页 PDF的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我需要实现使用多页文本创建pdf的功能.
I need to implement a functionality of creating pdf with multiple pages of a text.
class PDFCreator {
func prepareData() -> Data {
//1
let pdfMetaData = [
kCGPDFContextCreator: "PDF Creator",
kCGPDFContextAuthor: "Pratik Sodha",
kCGPDFContextTitle: "My PDF"
]
//2
let format = UIGraphicsPDFRendererFormat()
format.documentInfo = pdfMetaData as [String: Any]
//3
let pageWidth = 8.5 * 72.0
let pageHeight = 11 * 72.0
let pageRect = CGRect(x: 0, y: 0, width: pageWidth, height: pageHeight)
//4
let renderer = UIGraphicsPDFRenderer(bounds: pageRect, format: format)
//5
let data = renderer.pdfData { (context) in
//6
context.beginPage()
self.addText("Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.", pageRect: pageRect)
}
return data
}
@discardableResult
func addText(_ text : String, pageRect: CGRect) -> CGFloat {
// 1
let textFont = UIFont.systemFont(ofSize: 60.0, weight: .regular)
// 2
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.alignment = .natural
paragraphStyle.lineBreakMode = .byWordWrapping
// 3
let textAttributes = [
NSAttributedString.Key.paragraphStyle: paragraphStyle,
NSAttributedString.Key.font: textFont
]
let attributedText = NSAttributedString(string: text, attributes: textAttributes)
let textSize = attributedText.boundingRect(with: pageRect.size, options: [.usesFontLeading, .usesLineFragmentOrigin], context: nil)
// 4
let textRect = CGRect(x: 10,
y: 10,
width: pageRect.width - 20,
height: textSize.height)
attributedText.draw(in: textRect)
return textRect.origin.y + textRect.size.height
}
}
使用 PDFCreator 类准备 pdf 数据并使用 PDFView 显示.
Using PDFCreator class prepare pdf data and display using PDFView.
import UIKit
import PDFKit
class PDFPreviewViewController: UIViewController {
//1
@IBOutlet weak private var pdfView : PDFView!
override func viewDidLoad() {
super.viewDidLoad()
//2
let pdfData = PDFCreator().prepareData()
//3
pdfView.document = PDFDocument(data: pdfData)
pdfView.autoScales = true
}
}
实际输出
异常输出
整个文本将以 PDF 格式显示在新的 PDF 页面中，而不会减小字体大小.
Whole text will be in PDF with new PDF page without decreasing font size.
非常感谢任何帮助.谢谢你.
Any help much appreciated. Thank you.
推荐答案
输出
使用 CTFramesetterCreateFrame 和 CFAttributedStringGetLength
<小时>
class PDFCreator {
lazy var pageWidth : CGFloat = {
return 8.5 * 72.0
}()
lazy var pageHeight : CGFloat = {
return 11 * 72.0
}()
lazy var pageRect : CGRect = {
CGRect(x: 0, y: 0, width: pageWidth, height: pageHeight)
}()
lazy var marginPoint : CGPoint = {
return CGPoint(x: 10, y: 10)
}()
lazy var marginSize : CGSize = {
return CGSize(width: self.marginPoint.x * 2 , height: self.marginPoint.y * 2)
}()
func prepareData() -> Data {
//1
let pdfMetaData = [
kCGPDFContextCreator: "PDF Creator",
kCGPDFContextAuthor: "Pratik Sodha",
kCGPDFContextTitle: "My PDF"
]
//2
let format = UIGraphicsPDFRendererFormat()
format.documentInfo = pdfMetaData as [String: Any]
//3
let renderer = UIGraphicsPDFRenderer(bounds: pageRect, format: format)
//5
let data = renderer.pdfData { (context) in
//6
self.addText("Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.", context: context)
}
return data
}
@discardableResult
func addText(_ text : String, context : UIGraphicsPDFRendererContext) -> CGFloat {
// 1
let textFont = UIFont.systemFont(ofSize: 60.0, weight: .regular)
// 2
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.alignment = .natural
paragraphStyle.lineBreakMode = .byWordWrapping
// 3
let textAttributes = [
NSAttributedString.Key.paragraphStyle: paragraphStyle,
NSAttributedString.Key.font: textFont
]
//4
let currentText = CFAttributedStringCreate(nil,
text as CFString,
textAttributes as CFDictionary)
//5
let framesetter = CTFramesetterCreateWithAttributedString(currentText!)
//6
var currentRange = CFRangeMake(0, 0)
var currentPage = 0
var done = false
repeat {
//7
/* Mark the beginning of a new page.*/
context.beginPage()
//8
/*Draw a page number at the bottom of each page.*/
currentPage += 1
drawPageNumber(currentPage)
//9
/*Render the current page and update the current range to
point to the beginning of the next page. */
currentRange = renderPage(currentPage,
withTextRange: currentRange,
andFramesetter: framesetter)
//10
/* If we're at the end of the text, exit the loop. */
if currentRange.location == CFAttributedStringGetLength(currentText) {
done = true
}
} while !done
return CGFloat(currentRange.location + currentRange.length)
}
func renderPage(_ pageNum: Int, withTextRange currentRange: CFRange, andFramesetter framesetter: CTFramesetter?) -> CFRange {
var currentRange = currentRange
// Get the graphics context.
let currentContext = UIGraphicsGetCurrentContext()
// Put the text matrix into a known state. This ensures
// that no old scaling factors are left in place.
currentContext?.textMatrix = .identity
// Create a path object to enclose the text. Use 72 point
// margins all around the text.
let frameRect = CGRect(x: self.marginPoint.x, y: self.marginPoint.y, width: self.pageWidth - self.marginSize.width, height: self.pageHeight - self.marginSize.height)
let framePath = CGMutablePath()
framePath.addRect(frameRect, transform: .identity)
// Get the frame that will do the rendering.
// The currentRange variable specifies only the starting point. The framesetter
// lays out as much text as will fit into the frame.
let frameRef = CTFramesetterCreateFrame(framesetter!, currentRange, framePath, nil)
// Core Text draws from the bottom-left corner up, so flip
// the current transform prior to drawing.
currentContext?.translateBy(x: 0, y: self.pageHeight)
currentContext?.scaleBy(x: 1.0, y: -1.0)
// Draw the frame.
CTFrameDraw(frameRef, currentContext!)
// Update the current range based on what was drawn.
currentRange = CTFrameGetVisibleStringRange(frameRef)
currentRange.location += currentRange.length
currentRange.length = CFIndex(0)
return currentRange
}
func drawPageNumber(_ pageNum: Int) {
let theFont = UIFont.systemFont(ofSize: 20)
let pageString = NSMutableAttributedString(string: "Page (pageNum)")
pageString.addAttribute(NSAttributedString.Key.font, value: theFont, range: NSRange(location: 0, length: pageString.length))
let pageStringSize = pageString.size()
let stringRect = CGRect(x: (pageRect.width - pageStringSize.width) / 2.0,
y: pageRect.height - (pageStringSize.height) / 2.0 - 15,
width: pageStringSize.width,
height: pageStringSize.height)
pageString.draw(in: stringRect)
}
}
使用 PDFCreator 类准备 pdf 数据并使用 PDFView 显示.
Using PDFCreator class prepare pdf data and display using PDFView.
import UIKit
import PDFKit
class PDFPreviewViewController: UIViewController {
//1
@IBOutlet weak private var pdfView : PDFView!
override func viewDidLoad() {
super.viewDidLoad()
//2
let pdfData = PDFCreator().prepareData()
//3
pdfView.document = PDFDocument(data: pdfData)
pdfView.autoScales = true
}
}
这篇关于创建多页 PDF的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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