swift3

问题 I have a option string and want to convert that to double. this worked in Swift 2 , but since converted to Swift 3, I am getting value of 0. var dLati = 0.0 dLati = (latitude as NSString).doubleValue I have check and latitude has a optional string value of something like -80.234543218675654 , but dLati value is 0 *************** ok, new update for clarity ***************** I have a viewcontroller which i have a button in it, and when the button is touched, it will call another viewcontroller

问题 Hello I'm trying to access my constraint from my second view controller to my initial view controller, but it always give an error, Im accessing my constraint from a pageviewontroller class, to automatically adjust the height of my second page. found nil while unwrapping optional value func pageViewController(_ pageViewController: UIPageViewController, viewControllerAfter viewController: UIViewController) -> UIViewController? { guard let viewControllerIndex = orderedViewControllers.index(of:

问题 I was wondering what the physicsBody of a parent would be if all I do is this: let combinedBodies = SKSpriteNode() addChild(combinedBodies) //Create its children like this as an example: let child = SKSpriteNode(color: UIColor.red, size: CGSize(width: 10, height: 20)) child.physicsBody = SKPhysicsBody(rectangleOf: child.size) child.physicsBody?.categoryBitMask = collisionType.child.rawValue combinedBodies.addChild(child) allBodies.append(child.physicsBody?) Would the physicsBody of

问题 I'm trying to draw a dashed bottom border to UITableViewCells with the following code: func addDashedBottomBorder(to cell: UITableViewCell) { let width = CGFloat(2.0) let dashedBorderLayer: CAShapeLayer = CAShapeLayer() let frameSize = cell.frame.size let shapeRect = CGRect(x: 0, y: frameSize.height, width: frameSize.width*2, height: 1) dashedBorderLayer.bounds = shapeRect dashedBorderLayer.position = CGPoint(x: 0, y: frameSize.height) dashedBorderLayer.strokeColor = UIColor.lightGray.cgColor

问题 I have post response i want to download image from image_path let fileUrl = NSURL(fileURLWithPath: (posts.value(forKey: "image_path") as! [String])[indexPath.row]) print(fileUrl as Any) // here i can get path if FileManager.default.fileExists(atPath: (fileUrl)// nil value { let url = NSURL(string: (posts.value(forKey: "image_path") as! [String])[indexPath.row]) // Here url found nil let data = NSData(contentsOf: url! as URL) cell.LocationImage?.image = UIImage(data: data! as Data) } UPDATE:

问题 I have successfully to load a pdf file from URL to a web view. I want to get the coordinates after touch on webview to sent it data to server to add some text to that position in server side. Problem is how can I get that coordinates when webview is zooming or scroll to page 2,3.. Could you please help me to solve the problem in Swift 3 Here the code class ViewController: UIViewController, UITextFieldDelegate, UIGestureRecognizerDelegate, UIWebViewDelegate { @IBOutlet var imageView:

问题 When user press [Return] key then need to display the number. Like serial numbers [1,2 etc] for each line.Is there any way to do that? Following code I tried func textView(_ textView: UITextView, shouldChangeTextIn range: NSRange, replacementText text: String) -> Bool { var textview_text_nssring = textView.text as NSString // Add "1" when the user starts typing into the text field if (range.location == 0 && textView.text.isEmpty ) { if text == "\n" { textView.text = "1." let cursor =

问题 I have taken collection view in tableview cell now when I click the collection view cell it will go to the next view controller,is it possible? I have tried did select item method in that how to use perform segue method 回答1: I am showing u example class ViewController: UIViewController, UITableViewDelegate, UITableViewDataSource { @IBOutlet weak var tableView: UITableView! override func shouldPerformSegue(withIdentifier identifier: String, sender: Any?) -> Bool { return false } } This

问题 I was using a label before and it was working fine. But I just realized I need a UITextView instead and I cant seem to get it working right. The text just keeps going to the right and I can no longer see it. I need it to adjust to the dynamic height of the cell liked it worked before with the label. struct postStruct { let username : String! let message : String! let photoURL : String! let timeStamp: String! let cellUserId : String! } class GeneralChatroom: UIViewController,

问题 I've implemented an audioplayer on iOS 10.2.1 with XCode Version 8.2.1 (8C1002) on Mac OS Sierra 10.12.3 When the song starts playing the volume drops quite a bit after a couple of seconds. Has anyone experienced such an effect? do { myAudioPlayer = try AVAudioPlayer(contentsOf: url!) myAudioPlayer.prepareToPlay() myAudioPlayer.volume = 1.0 } catch { print(error) } 来源： https://stackoverflow.com/questions/43076669/avaudioplayer-volume-drops-after-couple-of-seconds