Open PDF Documents in swift

使用下面的範例，就可以開啟  PDF 來 preview 也可以 OpenIn 到其他 app 裡。

Obj-C 的範例：
https://stackoverflow.max-everyday.com/2017/05/open-pdf-documents-in-ios/

Swift 範例：

class ViewController: UIViewController, UIDocumentInteractionControllerDelegate {

    var docController:UIDocumentInteractionController!


    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.

        if let fileURL = NSBundle.mainBundle().pathForResource("SamplePDF1", ofType: "pdf") { // Use if let to unwrap to fileURL variable if file exists
            docController = UIDocumentInteractionController(URL: NSURL(fileURLWithPath: fileURL))

            docController.name = NSURL(fileURLWithPath: fileURL).lastPathComponent

            docController.delegate = self

            docController.presentPreviewAnimated(true)
        }


    }

    func documentInteractionControllerViewControllerForPreview(controller: UIDocumentInteractionController) -> UIViewController {
        return self
    }
     func documentInteractionControllerDidEndPreview(controller: UIDocumentInteractionController) {
        docController = nil
    }