我的应用程序使用WKWebView显示HTML页面，然后使用我从SO复制的功能将页面转换为PDF。转换在模拟器上运行但在实际设备上失败。如下所示，pdf数据的大小在模拟器上是正确的，但在设备上显着缩短，表明转换失败。我可以在模拟器上查看转换后的PDF。 viewController如下所示。我使用的是OS 10.3。我还在iPhone 6+和模拟器上进行了测试。同样的问题。
import UIKit
import WebKit
class ViewController: UIViewController {
var webView: WKWebView?
var dict = [String:String]()
func fileToURL(file: String) -> URL? {
// Get the full path of the file
guard let document = (NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true).first) else {
return nil
}
return URL(fileURLWithPath: document+file)
}
var activityButton: UIBarButtonItem!
override func viewDidLoad() {
super.viewDidLoad()
navigationItem.rightBarButtonItem = UIBarButtonItem(title: "PDF", style: .plain, target: self, action: #selector(exportHTMLContentToPDF))
let leftBarButtonItem = UIBarButtonItem(title: "Back", style: .plain, target: self, action: #selector(backAction))
navigationItem.leftBarButtonItem = leftBarButtonItem
let config = WKWebViewConfiguration()
let frame = view.frame
webView = WKWebView(frame:frame , configuration:config)
webView?.autoresizingMask = [UIViewAutoresizing.flexibleWidth, UIViewAutoresizing.flexibleHeight]
let reportFilename = "report"
createWebView(htmlFileName: reportFilename)
}
override func viewDidAppear(_ animated: Bool) {
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
func createWebView(htmlFileName: String) {
let url = Bundle.main.url(forResource: htmlFileName, withExtension: "html")!
let webView = WKWebView()
webView.loadFileURL(url, allowingReadAccessTo: url)
webView.translatesAutoresizingMaskIntoConstraints = false
self.view.addSubview(webView)
// Auto Layout
let views = ["webView": webView]
let c1 = NSLayoutConstraint.constraints(withVisualFormat: "H:|[webView]|", options: [], metrics: nil, views: views)
let c2 = NSLayoutConstraint.constraints(withVisualFormat: "V:[webView]|", options: [], metrics: nil, views: views)
let c3 = NSLayoutConstraint(item: webView, attribute: .top, relatedBy: .equal, toItem: self.topLayoutGuide , attribute: .bottom, multiplier: 1, constant: 0)
NSLayoutConstraint.activate(c1 + c2 + [c3])
// Pass the reference to the View's Controller
self.webView = webView
URLCache.shared.removeAllCachedResponses()
URLCache.shared.diskCapacity = 0
URLCache.shared.memoryCapacity = 0
let request = URLRequest(url: url)
self.webView?.load(request)
}
func backAction() {
dismiss(animated: true, completion: nil)
}
func exportHTMLContentToPDF(sender: UIBarButtonItem) {
let filename = "report.pdf"
createPdfFromView(aView: webView!, saveToDocumentsWithFileName: filename)
//pdfDataWithWebView(webView: webView!, view:self.view, filename: filename)
}
func createPdfFromView(aView: UIView, saveToDocumentsWithFileName fileName: String)
{
let pdfData = NSMutableData()
UIGraphicsBeginPDFContextToData(pdfData, aView.bounds, nil)
UIGraphicsBeginPDFPage()
guard let pdfContext = UIGraphicsGetCurrentContext() else {
print("ERROR: ",(#function))
return }
aView.layer.render(in: pdfContext)
UIGraphicsEndPDFContext()
if let documentDirectories = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true).first {
let documentsFileName = documentDirectories + "/" + fileName
debugPrint(documentsFileName)
pdfData.write(toFile: documentsFileName, atomically: true)
let filePath = documentsFileName
var fileSize : UInt64
do {
//return [FileAttributeKey : Any]
let attr = try FileManager.default.attributesOfItem(atPath: filePath)
fileSize = attr[FileAttributeKey.size] as! UInt64
//if you convert to NSDictionary, you can get file size old way as well.
let dict = attr as NSDictionary
fileSize = dict.fileSize()
print("fileSize = \(fileSize)")
} catch {
print("Error: \(error)")
}
print("SAVED: \(documentsFileName)")
}
}
}
整个项目是testHTMLtoPDF 两种情况的控制台日志如下所示：
在模拟器（iPad Air 2）上运行
fileSize = 302726
在设备上运行：iPad4（128 G） 2017-06-17 13：56：34.865220-0400 testHTMLtoPDF [20652：5079739]无法发出信号服务com.apple.WebKit.WebContent：113：找不到指定的服务 2017-06-17 13：56：34.871854-0400 testHTMLtoPDF [20652：5079739]无法发出服务信号com.apple.WebKit.Networking：113：找不到指定的服务 “/var/mobile/Containers/Data/Application/E280AA2C-CF4D-4B9C-8777-CD4B87C95320/Documents/report.pdf”
fileSize = 3812