[英]Convert PDF to UIImage
func drawOnPDF(path: String)
{
// Get existing Pdf reference
let pdf = CGPDFDocumentCreateWithURL(NSURL(fileURLWithPath: path))
// Get page count of pdf, so we can loop through pages and draw them accordingly
let pageCount = CGPDFDocumentGetNumberOfPages(pdf);
// Write to file
UIGraphicsBeginPDFContextToFile(path, CGRectZero, nil)
// Write to data
// var data = NSMutableData()
// UIGraphicsBeginPDFContextToData(data, CGRectZero, nil)
for index in 1...pageCount {
let page = CGPDFDocumentGetPage(pdf, index)
let pageFrame = CGPDFPageGetBoxRect(page, kCGPDFMediaBox)
UIGraphicsBeginPDFPageWithInfo(pageFrame, nil)
var ctx = UIGraphicsGetCurrentContext()
// Draw existing page
CGContextSaveGState(ctx);
CGContextScaleCTM(ctx, 1, -1);
CGContextTranslateCTM(ctx, 0, -pageFrame.size.height);
CGContextDrawPDFPage(ctx, page);
CGContextRestoreGState(ctx);
// Draw image on top of page
var image = UIImage(named: "signature3")
image?.drawInRect(CGRectMake(100, 100, 100, 100))
// Draw red box on top of page
//UIColor.redColor().set()
//UIRectFill(CGRectMake(20, 20, 100, 100));
}
UIGraphicsEndPDFContext()
}
我的问题是 PDF 转换为图像但是如何在视图中打开图像然后向左、向右、向上和向下滑动怎么可能
斯威夫特 3:
func convertPDFPageToImage(page:Int) {
let documentsURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0]
let filePath = documentsURL.appendingPathComponent("pathLocation").path
do {
let pdfdata = try NSData(contentsOfFile: filePath, options: NSData.ReadingOptions.init(rawValue: 0))
let pdfData = pdfdata as CFData
let provider:CGDataProvider = CGDataProvider(data: pdfData)!
let pdfDoc:CGPDFDocument = CGPDFDocument(provider)!
pageCount = pdfDoc.numberOfPages;
let pdfPage:CGPDFPage = pdfDoc.page(at: page)!
var pageRect:CGRect = pdfPage.getBoxRect(.mediaBox)
pageRect.size = CGSize(width:pageRect.size.width, height:pageRect.size.height)
print("\(pageRect.width) by \(pageRect.height)")
UIGraphicsBeginImageContext(pageRect.size)
let context:CGContext = UIGraphicsGetCurrentContext()!
context.saveGState()
context.translateBy(x: 0.0, y: pageRect.size.height)
context.scaleBy(x: 1.0, y: -1.0)
context.concatenate(pdfPage.getDrawingTransform(.mediaBox, rect: pageRect, rotate: 0, preserveAspectRatio: true))
context.drawPDFPage(pdfPage)
context.restoreGState()
let pdfImage:UIImage = UIGraphicsGetImageFromCurrentImageContext()!
UIGraphicsEndImageContext()
self.imageView.image = pdfImage
}
catch {
}
}
我得到了 UIImage 中 Pdf 页面转换的解决方案。 此代码 PDF 页面在 Uiimage 中转换并保存在图像文档目录中。 PDF 下载和页面计数以分离页面虎钳图像转换。
func drawOnPDF(path: String)
{
var urlstr: NSURL = NSURL.fileURLWithPath(path)!
var pdf: CGPDFDocumentRef = CGPDFDocumentCreateWithURL(urlstr)
var page: CGPDFPageRef;
var frame: CGRect = CGRectMake(0, 0, 100, 200)
var pageCount: Int = CGPDFDocumentGetNumberOfPages(pdf);
for (var i = 0; i < pageCount; i++)
{
var mypage: CGPDFPageRef = CGPDFDocumentGetPage(pdf, i+1)
frame = CGPDFPageGetBoxRect(mypage, kCGPDFMediaBox)
UIGraphicsBeginImageContext(CGSizeMake(600, 600*(frame.size.height/frame.size.width)))
var ctx: CGContextRef = UIGraphicsGetCurrentContext()
CGContextSaveGState(ctx)
CGContextTranslateCTM(ctx, 0.0, frame.size.height)
CGContextScaleCTM(ctx, 1.0, -1.0)
CGContextSetGrayFillColor(ctx, 1.0, 1.0)
CGContextFillRect(ctx, frame)
page = CGPDFDocumentGetPage(pdf, i + 1)
var pdfTransform: CGAffineTransform = CGPDFPageGetDrawingTransform(page, kCGPDFMediaBox, frame, 0, true)
CGContextConcatCTM(ctx, pdfTransform);
CGContextSetInterpolationQuality(ctx, kCGInterpolationHigh)
CGContextSetRenderingIntent(ctx, kCGRenderingIntentDefault)
CGContextDrawPDFPage(ctx, page)
var thumbnailImage: UIImage = UIGraphicsGetImageFromCurrentImageContext()
CGContextRestoreGState(ctx)
var documentsPath = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true).last! as! String
documentsPath = documentsPath.stringByAppendingFormat("/Page%d.png", i+1)
UIGraphicsEndImageContext()
imagedata = UIImagePNGRepresentation(thumbnailImage)
imagedata.writeToFile(documentsPath, atomically: true)
array.addObject(documentsPath)
}
let dirPath = array.objectAtIndex(0) as? String
let image = UIImage(contentsOfFile: dirPath!)
NSUserDefaults.standardUserDefaults().setObject(array, forKey: "Array")
println("\(array)")
}
我找到了一个很酷的解决方案。 从这里借用: https : //www.hackingwithswift.com/example-code/core-graphics/how-to-render-a-pdf-to-an-image
func drawPDFfromURL(url: URL) -> UIImage? {
guard let document = CGPDFDocument(url as CFURL) else { return nil }
guard let page = document.page(at: 1) else { return nil }
let pageRect = page.getBoxRect(.mediaBox)
let renderer = UIGraphicsImageRenderer(size: pageRect.size)
let img = renderer.image { ctx in
UIColor.white.set()
ctx.fill(pageRect)
ctx.cgContext.translateBy(x: 0.0, y: pageRect.size.height)
ctx.cgContext.scaleBy(x: 1.0, y: -1.0)
ctx.cgContext.drawPDFPage(page)
}
return img
}
所有这些解决方案将单个 pdf 页面转换为UIImage
。 这是我将多页 pdf 转换为单个图像的发现
func drawPDFfromURL(url: URL) -> UIImage? {
guard let document = CGPDFDocument(url as CFURL) else { return nil }
var width: CGFloat = 0
var height: CGFloat = 0
// calculating overall page size
for index in 1...document.numberOfPages {
print("index: \(index)")
if let page = document.page(at: index) {
let pageRect = page.getBoxRect(.mediaBox)
width = max(width, pageRect.width)
height = height + pageRect.height
}
}
// now creating the image
let renderer = UIGraphicsImageRenderer(size: CGSize(width: width, height: height))
let image = renderer.image { (ctx) in
ctx.cgContext.scaleBy(x: 1.0, y: -1.0)
for index in 1...document.numberOfPages {
if let page = document.page(at: index) {
let pageRect = page.getBoxRect(.mediaBox)
ctx.cgContext.translateBy(x: 0.0, y: -pageRect.height)
ctx.cgContext.drawPDFPage(page)
}
}
ctx.cgContext.scaleBy(x: 1.0, y: -1.0)
}
return image
}
使用 PDFKit:
1)获取pdf路径
2)访问要转换为图像的pdf页面:
let pdfPage = PDFDocument(url: pdfPath)?.page(at: 0)
3)使用缩略图function转换页面tp图像:
let pdfImage = pdfPage?.thumbnail(of: self.pdfPageBounds.size, for: .mediaBox)
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