我想构建一个应用程序，该应用程序还可以在应用程序中显示和保存PDF，并在表视图中显示它们（作为文件系统），当我点击一个PDF时打开它们。
以下是我的重要问题：
1.如何在我的应用程序上本地保存PDF（例如，如果用户可以输入url），以及它将在哪里保存
2.保存时，如何在表视图中显示所有本地存储的文件以打开它们
由于有几个人要求这样做，这里的答案相当于Swift中的第一个答案：
//The URL to Save
let yourURL = NSURL(string: "http://somewebsite.com/somefile.pdf")
//Create a URL request
let urlRequest = NSURLRequest(URL: yourURL!)
//get the data
let theData = NSURLConnection.sendSynchronousRequest(urlRequest, returningResponse: nil, error: nil)
//Get the local docs directory and append your local filename.
var docURL = (NSFileManager.defaultManager().URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask)).last as? NSURL
docURL = docURL?.URLByAppendingPathComponent( "myFileName.pdf")
//Lastly, write your file to the disk.
theData?.writeToURL(docURL!, atomically: true)
此外，由于此代码使用同步网络请求，我强烈建议将其调度到后台队列：
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), { () -> Void in
//The URL to Save
let yourURL = NSURL(string: "http://somewebsite.com/somefile.pdf")
//Create a URL request
let urlRequest = NSURLRequest(URL: yourURL!)
//get the data
let theData = NSURLConnection.sendSynchronousRequest(urlRequest, returningResponse: nil, error: nil)
//Get the local docs directory and append your local filename.
var docURL = (NSFileManager.defaultManager().URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask)).last as? NSURL
docURL = docURL?.URLByAppendingPathComponent( "myFileName.pdf")
//Lastly, write your file to the disk.
theData?.writeToURL(docURL!, atomically: true)
})
Swift中第二个问题的答案：
//Getting a list of the docs directory
let docURL = (NSFileManager.defaultManager().URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask).last) as? NSURL
//put the contents in an array.
var contents = (NSFileManager.defaultManager().contentsOfDirectoryAtURL(docURL!, includingPropertiesForKeys: nil, options: NSDirectoryEnumerationOptions.SkipsHiddenFiles, error: nil))
//print the file listing to the console
println(contents)
Swift 4.1
func savePdf(urlString:String, fileName:String) {
DispatchQueue.main.async {
let url = URL(string: urlString)
let pdfData = try? Data.init(contentsOf: url!)
let resourceDocPath = (FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)).last! as URL
let pdfNameFromUrl = "YourAppName-(fileName).pdf"
let actualPath = resourceDocPath.appendingPathComponent(pdfNameFromUrl)
do {
try pdfData?.write(to: actualPath, options: .atomic)
print("pdf successfully saved!")
} catch {
print("Pdf could not be saved")
}
}
}
func showSavedPdf(url:String, fileName:String) {
if #available(iOS 10.0, *) {
do {
let docURL = try FileManager.default.url(for: .documentDirectory, in: .userDomainMask, appropriateFor: nil, create: false)
let contents = try FileManager.default.contentsOfDirectory(at: docURL, includingPropertiesForKeys: [.fileResourceTypeKey], options: .skipsHiddenFiles)
for url in contents {
if url.description.contains("(fileName).pdf") {
// its your file! do what you want with it!
}
}
} catch {
print("could not locate pdf file !!!!!!!")
}
}
}
// check to avoid saving a file multiple times
func pdfFileAlreadySaved(url:String, fileName:String)-> Bool {
var status = false
if #available(iOS 10.0, *) {
do {
let docURL = try FileManager.default.url(for: .documentDirectory, in: .userDomainMask, appropriateFor: nil, create: false)
let contents = try FileManager.default.contentsOfDirectory(at: docURL, includingPropertiesForKeys: [.fileResourceTypeKey], options: .skipsHiddenFiles)
for url in contents {
if url.description.contains("YourAppName-(fileName).pdf") {
status = true
}
}
} catch {
print("could not locate pdf file !!!!!!!")
}
}
return status
}
我给出了一个在iOS中存储和检索pdf文档的示例。我希望这就是你想要的。
1.如何在我的应用程序上本地保存PDF（例如，如果用户可以输入url），以及它将在哪里保存
// the URL to save
NSURL *yourURL = [NSURL URLWithString:@"http://yourdomain.com/yourfile.pdf"];
// turn it into a request and use NSData to load its content
NSURLRequest *request = [NSURLRequest requestWithURL:result.link];
NSData *data = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];
// find Documents directory and append your local filename
NSURL *documentsURL = [[[NSFileManager defaultManager] URLsForDirectory:NSDocumentDirectory inDomains:NSUserDomainMask] lastObject];
documentsURL = [documentsURL URLByAppendingPathComponent:@"localFile.pdf"];
// and finally save the file
[data writeToURL:documentsURL atomically:YES];
2.保存时，如何在表视图中显示所有本地存储的文件以打开它们
您可以检查文件是否已下载，也可以列出Documents目录，如下所示：
// list contents of Documents Directory just to check
NSURL *documentsURL = [[[NSFileManager defaultManager] URLsForDirectory:NSDocumentDirectory inDomains:NSUserDomainMask] lastObject];
NSArray *contents = [[NSFileManager defaultManager]contentsOfDirectoryAtURL:documentsURL includingPropertiesForKeys:nil options:NSDirectoryEnumerationSkipsHiddenFiles error:nil];
NSLog(@"%@", [contents description]);
使用Swift在Webview中下载并显示PDF。
let request = URLRequest(url: URL(string: "http://<your pdf url>")!)
let config = URLSessionConfiguration.default
let session = URLSession(configuration: config)
let task = session.dataTask(with: request, completionHandler: {(data, response, error) in
if error == nil{
if let pdfData = data {
let pathURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0].appendingPathComponent("(filename).pdf")
do {
try pdfData.write(to: pathURL, options: .atomic)
}catch{
print("Error while writting")
}
DispatchQueue.main.async {
self.webView.delegate = self
self.webView.scalesPageToFit = true
self.webView.loadRequest(URLRequest(url: pathURL))
}
}
}else{
print(error?.localizedDescription ?? "")
}
}); task.resume()
如果您想在Files应用程序中存储文件，请添加`
NSURL *url = [NSURL URLWithString:@"PATH TO PDF"];
UIDocumentPickerViewController *documentPicker = [[UIDocumentPickerViewController alloc] initWithURL:url inMode:UIDocumentPickerModeExportToService];
[documentPicker setDelegate:self];
[self presentViewController:documentPicker animated:YES completion:nil];
以下是委托方法
- (void)documentPickerWasCancelled:(UIDocumentPickerViewController *)controller {
}
- (void)documentPicker:(UIDocumentPickerViewController *)controller didPickDocumentsAtURLs:(NSArray<NSURL *> *)urls {
}
它将打开DocumentPickerViewController，您可以在其中选择一个文件夹来存储文件。
需要iOS11或更高版本。
如果您想打印目录URL中的PDF数据，请使用：
let printInfo = NSPrintInfo.shared
let manager = FileManager.default
do{
let directoryURL = try manager.url(for: .documentDirectory, in:.userDomainMask, appropriateFor:nil, create:true)
let docURL = NSURL(string:"LadetagMahlzeiten.pdf", relativeTo:directoryURL)
let pdfDoc = PDFDocument.init(url: docURL! as URL)
let page = CGRect(x: 0, y: 0, width: 595.2, height: 1841.8) // A4, 72 dpi
let pdfView : PDFView = PDFView.init(frame: page)
pdfView.document = pdfDoc
let operation: NSPrintOperation = NSPrintOperation(view: pdfView, printInfo: printInfo)
operation.printPanel.options.insert(NSPrintPanel.Options.showsPaperSize)
operation.printPanel.options.insert(NSPrintPanel.Options.showsOrientation)
operation.run()
}catch{
}
//savePdf(urlString:url, fileName:fileName)
let urlString = "here String with your URL"
let url = URL(string: urlString)
let fileName = String((url!.lastPathComponent)) as NSString
// Create destination URL
let documentsUrl:URL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first as URL!
let destinationFileUrl = documentsUrl.appendingPathComponent("(fileName)")
//Create URL to the source file you want to download
let fileURL = URL(string: urlString)
let sessionConfig = URLSessionConfiguration.default
let session = URLSession(configuration: sessionConfig)
let request = URLRequest(url:fileURL!)
let task = session.downloadTask(with: request) { (tempLocalUrl, response, error) in
if let tempLocalUrl = tempLocalUrl, error == nil {
// Success
if let statusCode = (response as? HTTPURLResponse)?.statusCode {
print("Successfully downloaded. Status code: (statusCode)")
}
do {
try FileManager.default.copyItem(at: tempLocalUrl, to: destinationFileUrl)
do {
//Show UIActivityViewController to save the downloaded file
let contents = try FileManager.default.contentsOfDirectory(at: documentsUrl, includingPropertiesForKeys: nil, options: .skipsHiddenFiles)
for indexx in 0..<contents.count {
if contents[indexx].lastPathComponent == destinationFileUrl.lastPathComponent {
let activityViewController = UIActivityViewController(activityItems: [contents[indexx]], applicationActivities: nil)
self.present(activityViewController, animated: true, completion: nil)
}
}
}
catch (let err) {
print("error: (err)")
}
} catch (let writeError) {
print("Error creating a file (destinationFileUrl) : (writeError)")
}
} else {
print("Error took place while downloading a file. Error description: (error?.localizedDescription ?? "")")
}
}
task.resume()
}
对于Swift 5及以上版本：将基于PDF的64字符串数据保存到文档目录
创建一个文件夹，用于保存名为的PDF文件
fileprivate func getFilePath() -> URL? {
let documentDirectoryURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0]
let directoryURl = documentDirectoryURL.appendingPathComponent("Invoice", isDirectory: true)
if FileManager.default.fileExists(atPath: directoryURl.path) {
return directoryURl
} else {
do {
try FileManager.default.createDirectory(at: directoryURl, withIntermediateDirectories: true, attributes: nil)
return directoryURl
} catch {
print(error.localizedDescription)
return nil
}
}
}
将基于PDF的64字符串数据写入文档目录
fileprivate func saveInvoice(invoiceName: String, invoiceData: String) {
guard let directoryURl = getFilePath() else {
print("Invoice save error")
return }
let fileURL = directoryURl.appendingPathComponent("(invoiceName).pdf")
guard let data = Data(base64Encoded: invoiceData, options: .ignoreUnknownCharacters) else {
print("Invoice downloaded Error")
self.hideHUD()
return
}
do {
try data.write(to: fileURL, options: .atomic)
print("Invoice downloaded successfully")
} catch {
print(error.localizedDescription)
}
}