protocols

问题 I would like to know what the protocol equivalent is for an initializer in a simple class that only contains initializing functionality and is only intended to be extended in a concrete class. So probably the easiest is to show the code - I'm looking for the protocol extension equivalent of the following: import UIKit class Thing { var color:UIColor init(color:UIColor) { self.color = color } } class NamedThing:Thing { var name:String init(name:String,color:UIColor) { self.name = name super

问题 There is a lot of topic about http/2 protocol, but I wonder if there is a working website with this protocol. i.e. We can decide to use http:// or https:// but how to write a http/2 request? I am aware that this protocol depends on server capability, but can not find a way to check if some website e.g. google.com has http2 support enabled. As I can see in this picture, all modern browsers support this protocol. I have not seen any link that could look like a new generation protocol. My

问题 I’m trying to mix generics with protocols and I’m getting a really hard time xD I have certain architecture implemented in an Android/Java project, and I’m trying to rewrite it to fit it in a swift/iOS project. But I’ve found this limitation. ProtocolA protocol ProtocolA { } ProtocolB protocol ProtocolB : ProtocolA { } ImplementProtocolA class ImplementProtocolA <P : ProtocolA> { let currentProtocol : P init(currentProtocol : P) { self.currentProtocol = currentProtocol } } ImplementProtocolB

问题 Below I have pasted code which you should be able to paste into a Swift 3 playground and see the error. I have a protocol defined and create an empty array of that type. I then have a class which conforms to the protocol which I try to append to the array but I get the below error. protocol MyProtocol { var text: String { get } } class MyClass: MyProtocol { var text = "Hello" } var collection = [MyProtocol]() var myClassCollection = [MyClass(), MyClass()] collection.append(myClassCollection)

问题 Lets say I have two protocols: protocol TheirPcol {} protocol MyPcol { func extraFunc() } What I want to do is to create a protocol extension for 'TheirPcol' which lets extraFunc() work on anything which conforms to 'TheirPcol'. So something like this: extension TheirPcol : MyPcol { // Error 'Extension of protocol 'TheirPcol' cannot have an inheritance clause. func extraFunc() { /* do magic */} } struct TheirStruct:TheirPcol {} let inst = TheirStruct() inst.extraFunc() The kicker in this is

问题 URL u=new URL("telnet://route-server.exodus.net"); This line is generating : java.net.MalformedURLException: unknown protocol: telnet And i encounter similar problems with other URLs that begin with "news://" These are URLs extracted from ODP , so i dont understand why such exceptions arise.. 回答1: Issue Java throws a MalformedURLException because it couldn't find a URLStreamHandler for that protocol. Check the javadocs of the constructors for the details. Summary: Since the URL class has an

问题 Take the following protocol and extension: protocol ProtocolA { func myFunc() } extension ProtocolA { func myFunc() { print("Default ProtocolA implementation.") } } What is the difference, if any, between that and leaving the function out of the protocol definition entirely, like this: protocol ProtocolB { } extension ProtocolB { func myFunc() { print("Default ProtocolB implementation.") } } I found one difference. If I define a struct that overrides the default implementation, I can only

问题 Take the following protocol and extension: protocol ProtocolA { func myFunc() } extension ProtocolA { func myFunc() { print("Default ProtocolA implementation.") } } What is the difference, if any, between that and leaving the function out of the protocol definition entirely, like this: protocol ProtocolB { } extension ProtocolB { func myFunc() { print("Default ProtocolB implementation.") } } I found one difference. If I define a struct that overrides the default implementation, I can only

问题 I have two objects, both of which are view controllers. The first (Ill call it viewController1) declares a protocol. The second (which unsurprisingly I will name viewController2) conforms to this protocol. XCode is giving me a build error of: 'Cannot find protocol declaration for viewController1' I have seen various questions on this subject and I am certain it is to do with a loop error, but I just can't see it in my case... Code below.. viewController1.h @protocol viewController1Delegate;

问题 I have a question about accessing file with Samba JCIFS. So there is a server I want to access, let's call it server.unv.edu and the workgroup is WKGRP. there is a share in this server: \\server.unv.edu\pcb$ the way I am trying to access to the server is : public class SMBAuthenticator extends NtlmAuthenticator{ private String username = "username"; private String password = "password"; private String domain = "smb://server.unv.edu/WKGRP/"; public SMBAuthenticator(){ NtlmAuthenticator