protocols

问题 I thought I had finally managed to understand the concept of a delegate until the following occurred: I changed my header file to remove the reference to the delegate and the Alert still worked. The only difference is that I lose code hinting. //.h #import <UIKit/UIKit.h> //@interface ViewController : UIViewController <UIAlertViewDelegate> @interface ViewController : UIViewController - (IBAction)showMessage:(id)sender; @end //.m #import "ViewController.h" @implementation ViewController -

问题 Struggling for a while with, it will be really helpful if you can shed some light on this: I have an APIWorkerProtocol which has a property requirement, the required property is a protocol i.e DataParserProtocol protocol APIWorkerProtocol { var apiRequestProvider : APIRequestGeneratorProtocol {get} var dataParser : DataParserProtocol{get} func callAPI(completionHandler: @escaping (APICallResult<Self.ResultType>) -> Void) } protocol DataParserProtocol { associatedtype ExpectedRawDataType

问题 I am adopting WatchConnectivity, but I am still supporting iOS7 and iOS 8 for which this library is not available. Moreover I am adopting protocol WCSessionDelegate also not supported but this older systems. In ObjectiveC I would have used preprocessing directives to shield this declaration and the protocol adoption from versions not supporting them. How do I handle that in Swift so that the app does not crash on older systems? 回答1: I thank @joern for the suggestion of adopting the protocol

问题 This Objective-C protocol used to work in Swift 1.1, but now errors in Swift 1.2. Objective-C Protocol stripped down to the one problematic property: @protocol ISomePlugin <NSObject> @property (readonly, getter=getObjects) NSArray * objects; @end class SomePlugin: NSObject, ISomePlugin { var objects: [AnyObject]! = nil func getObjects() -> [AnyObject]! { objects = ["Hello", "World"]; return objects; } } Here is the Swift 1.2 error: Plugin.swift:4:1: error: type 'SomePlugin' does not conform

问题 I have tried converting proto to java pojo . But got the error [Stderr] Order.proto:12:18: Expected "required", "optional", or "repeated". [Stderr] Order.proto:12:21: Expected field name. optional int32 orderID = 1; optional int32 quantity = 2; map<string,string> map_field = 4; repeated string product = 3; Please help me what needs to be changed. i searched on google protobuf developer site https://developers.google.com/protocol-buffers/docs/proto#maps It says that Map fields cannot be

问题 I've written a Macintosh app that handles a custom protocol: <key>CFBundleURLTypes</key> <array> <dict> <key>CFBundleURLName</key> <string>My Cool Handler</string> <key>CFBundleURLSchemes</key> <array> <string>coolhandler</string> </array> </dict> </array> All well and good. It launches. However, I'm clicking on a link like this: coolhandler://Iwant/toparse/this In Windows, the registry entry is simple and this work just fine. When my Windows app launches, the whole url is passed as an

问题 I've written a Macintosh app that handles a custom protocol: <key>CFBundleURLTypes</key> <array> <dict> <key>CFBundleURLName</key> <string>My Cool Handler</string> <key>CFBundleURLSchemes</key> <array> <string>coolhandler</string> </array> </dict> </array> All well and good. It launches. However, I'm clicking on a link like this: coolhandler://Iwant/toparse/this In Windows, the registry entry is simple and this work just fine. When my Windows app launches, the whole url is passed as an

问题 I would like to call floating point methods on floating point types in swift. func example<T : FloatingPoint>(_ x:T) -> T { return cos(cbrt(x + 1)) } Is there a better way to do so than this? protocol SupportsFloatingPoint : FloatingPoint { var cubeRoot:Self { get } var cosine:Self { get } } extension Double : SupportsFloatingPoint { var cubeRoot:Double { return Darwin.cbrt(self) } var cosine:Double { return Darwin.cos(self) } } extension Float : SupportsFloatingPoint { var cubeRoot:Float {

问题 I have a MapViewController for presenting annotations on map. It contains an object of type MapPresentable. protocol MapPresentable { associatedtype AnnotationElement: MKAnnotation var annotations: [AnnotationElement] { get } } class MapViewController<M: MapPresentable>: UIViewController { var mapPresentable: M! } MapViewController can also present route on map in case mapPresentable conforms to RoutePresentable protocol. protocol RoutePresentable: MapPresentable { var getRouteLocations:

问题 I just realised there is a shell: URI, but every search engine seems to think shell: and shell are the same thing. The only thing I've found out is that you can type shell:startup right in explorer (XP & 7 tested) for obvious effects. This is good already because there is no %startup% , but I want to know what else is this capable of. Is there any MS reference on this? EDIT (even if it's not on MSDN) 回答1: Stuart seems to have found a fairly thorough list of the folders; I'll speak to the