swift3

问题 In Swift 3, what is the recommended way to put (potentially lots of) additional information in an error/exception that the catcher can use to solve/handle the problem? In all the examples I've seen, they use enum s with associated values, and that seems overly cumbersome/verbose for lots of information. Specifically, I am writing a simple parser and want a place to store the affected line and column numbers (and potentially other information in the future), but without requiring that every

问题 My question is I have implemented UISearchController in Swift 3 when I tried to filter it's easily filtered simple array but my case is little bit different I have one array which I fetch all the data from SQLite database in class so its array of class managerControlClassArray which has all the content of the class array. I want to filter the content in updateSearchResults delegate method but it's really difficult and stuck I did to much research and after not getting my desired query I found

问题 I can't seem to find any info on this flag, on StackOverflow or elsewhere on the web. Apple's own documentation only says: If a formatter is set to be lenient, when parsing a string it uses heuristics to guess at the date which is intended. As with any guessing, it may get the result date wrong (that is, a date other than that which was intended). Maybe I'm misunderstanding how this is supposed to work, but I can't get it to work at all. My guess was something like this (with a relatively

问题 In OTP, there are four textfields were used. Moving the cursor to the previous textfield while pressing on keyboard back button? 回答1: To detect the backspace event in a UITextField, first you need to set up a delegate for the UITextField and set it to self. class ViewController: UIViewController,UITextFieldDelegate self.textField.delegate = self Then you use the delegate method below to detect if a backspace was pressed func textField(_ textField: UITextField, shouldChangeCharactersIn range:

问题 I am using the follow code to fetch all smart albums: PHAssetCollection.fetchAssetCollections(with: PHAssetCollectionType.smartAlbum, subtype: PHAssetCollectionSubtype.albumRegular, options: nil) How can I exclude the Panoramas smart album from this fetch? I assume I have to add a predicate using the options param, but I don't know how to format the predicate. 回答1: If you want to exclude the Panoramas, consider using an array and fetching only the collection you need. In other words,

问题 I have created a big circle with a UIBezierPath and turned it into a Sprite using this, let path = UIBezierPath(arcCenter: CGPoint(x: 0, y: 0), radius: CGFloat(226), startAngle: 0.0, endAngle: CGFloat(M_PI * 2), clockwise: false) // create a shape from the path and customize it let shape = SKShapeNode(path: path.cgPath) shape.lineWidth = 20 shape.position = center shape.strokeColor = UIColor(red:0.98, green:0.99, blue:0.99, alpha:1.00) let trackViewTexture = self.view!.texture(from: shape,

问题 Is there any way to get all the list of installed application and check a specific bundle/app can be open which is already installed in swift ? 回答1: You can only open an app if you know its URL Scheme just like facebook provides for example. fb:// There is no way to get the list of applications. Can't say anything about jail broken devices. 来源： https://stackoverflow.com/questions/40327664/swift-get-all-installed-application-and-open-specific-one

问题 So, when my data model is ready, I tried to generate the subclasses when my data model file is open: Editor -> Create NSManaged Object Subclasses Okay, two files are generated, one is class declaration, the other is the property. However, I was immediately prompted that I did a redeclaration of a class that already exists. This is where the original generated files are: previously generated files My question is obvious: When were those two files generated? What to do if I want those files in

问题 So, when my data model is ready, I tried to generate the subclasses when my data model file is open: Editor -> Create NSManaged Object Subclasses Okay, two files are generated, one is class declaration, the other is the property. However, I was immediately prompted that I did a redeclaration of a class that already exists. This is where the original generated files are: previously generated files My question is obvious: When were those two files generated? What to do if I want those files in

问题 I'm using APAddressBook to get the address book from the users phone. it generates the following object of users when I print the variable serializedContacts : [[ AnyHashable("name"): { compositeName = "Mary Jones"; firstName = Mary; lastName = Jones; }, AnyHashable("recordID"): 111, AnyHashable("phones"): <__NSSingleObjectArrayI 0x17401c160>({ number = "0411 111 111"; }) ], [ AnyHashable("name"): { compositeName = "Jack Smith"; firstName = Jack; lastName = Smith; }, AnyHashable("recordID"):