protocols

问题 I want to define one protocol with few properties and need to use those properties in another NSObject subclass. Please give me link or example code. I need that to work with 10.5. Thanks PLEASE CHECK THE FOLLOWING SAMPLE CODE @protocol MyProtocol @property (nonatomic, readonly) id someObject; @property (nonatomic, getter=isAlive) BOOL alive; @end #import "MyProtocol.h" @interface MyCustomClass : NSObject <MyProtocol>{ } @end #import "MyCustomClass.h" @implementation MyCustomClass @synthesize

问题 Here is a generic question. I'm not in search of the best answer, I'd just like you to express your favourite practices. I want to implement a network protocol in Java (but this is a rather general question, I faced the same issues in C++), this is not the first time, as I have done this before. But I think I am missing a good way to implement it. In fact usually it's all about exchanging text messages and some byte buffers between hosts, storing the status and wait until the next message

问题 does anyone have a good definition for what a binary protocol is? and what is a text protocol actually? how do these compare to each other in terms of bits sent on the wire? here's what wikipedia says about binary protocols: A binary protocol is a protocol which is intended or expected to be read by a machine rather than a human being (http://en.wikipedia.org/wiki/Binary_protocol) oh come on! to be more clear, if I have jpg file how would that be sent through a binary protocol and how through

问题 Python 3.5 on windows, try these: import ssl, pickle, multiprocessing context = ssl.create_default_context() foo = pickle.dumps(context) pickle.loads(foo) Throws an exception: TypeError: __new__() missing 1 required positional argument: 'protocol' subclass of multiprocessing.Process throws the same exception: class Foo(multiprocessing.Process): def __init__(self): super().__init__() self.context = ssl.create_default_context() def run(self): pass if __name__ == '__main__': foo = Foo() foo

问题 Is HTTP headers limited to US-ASCII charset? Can I use unicode characters in HTTP headers? Edit : I want to do like this: WebClient myWebClient = new WebClient(); myWebClient.Headers.Add("Content-Type","یونیکد"); 回答1: First of all, the header field in your example does not allow what you want; media type names are ASCII. In theory, HTTP header field values can transport anything; the tricky part is to get all parties (sender, receiver, and intermediates) to agree on the encoding. Thus, the

问题 I've been looking in to the new Swift language trying to find what's the equivalent for an interface(in java) or a protocol(in objective-c) in Swift, after surfing on the internet and searching in the book provided by Apple, I still can't seem to find it. Does any one know what's the name of this component in swift and what's its syntax? 回答1: Protocols in Swift are very similar to Objc, except you may use them not only on classes, but also on structs and enums. protocol SomeProtocol { var

问题 Coming from an Eclipse / Java background, one of my favorite features is the ability to quickly stub out all the methods required by an interface. In Eclipse, I can choose 'Override / implement' from the source menu to generate stub methods for any method of the Interface. I'd like to do the same thing in Objective-C. For instance, if I declare a class that implements the 'NSCoding' protocol, I'd like to have Xcode automatically generate the methods required to implement this Protocol. It's

问题 I have a category on NSDate and it would be convenient if it could implement a protocol I previously created. Is this possible? what's the correct syntax for this? 回答1: Yes, that's possible. The syntax is: @interface NSDate (CategoryName) <ProtocolName> @end @implementation NSDate (CategoryName) @end Here's Apple's documentation on the topic. It's also possible to do this using a class extension. I very much like this to privately conform to delegate protocols. Doing so hides the

问题 I'm looking at some code from an auto layout library. In it, there is a protocol adopted by UIView: extension UIView: Constrainable {} extension UILayoutGuide: Constrainable { // LayoutGuide doesn't have baseline anchors, so just use the bottom anchor public var firstBaselineAnchor: NSLayoutYAxisAnchor { return bottomAnchor } public var lastBaselineAnchor: NSLayoutYAxisAnchor { return bottomAnchor } } public protocol Constrainable { var topAnchor: NSLayoutYAxisAnchor { get } var bottomAnchor:

问题 I'm trying to write an extension to satisfy a protocol in an extension like so: extension UIColor: JSONRepresentable { convenience init?(json: Any) { guard let colourArray = json as? [CGFloat] else { print("json was not an array of CGFloats") return nil } self.init(red: colourArray[0], green: colourArray[1], blue: colourArray[2], alpha: colourArray[3]) } } I'm getting this error: Initializer requirement 'init(json:)' can only be satisfied by a required initializer in the definition of non