protocols

问题 I've been looking for a way to use optional protocol methods and have clean code. In other words: 1: No respondsToSelector: calls all over my code 2. Should work for any method signature, so a category method on NSObject making the check and calling performSelector: is out (and NSInvocation has problems cooperating with ARC) 3: This solution, IMO, pretends to be universal but has all the drawbacks of 1 I eventually came up with this idea: @protocol MyProtocol <NSObject> @optional -(void

问题 I've been looking for a way to use optional protocol methods and have clean code. In other words: 1: No respondsToSelector: calls all over my code 2. Should work for any method signature, so a category method on NSObject making the check and calling performSelector: is out (and NSInvocation has problems cooperating with ARC) 3: This solution, IMO, pretends to be universal but has all the drawbacks of 1 I eventually came up with this idea: @protocol MyProtocol <NSObject> @optional -(void

问题 Suppose for example we're talking about elements of type Int (but the question still applies to any type) I have some functionality which needs to loop over a sequence of Ints. But I don't care if behind the scenes this sequence is implemented as an Array, or a Set or any other exotic kind of structure, the only requirement is that we can loop over them. Swift standard library defines the protocol SequenceType as "A type that can be iterated with a for...in loop". So my instinct is to define

问题 Consider a base UIViewController class... class Rooms: UIViewController { class func instantiate()->Rooms { } static func make()->Rooms { let emplacedAndSetup = self.instantiate() // various kodes here // very likely put s.view somewhere return emplacedAndSetup } sundryOtherFunctionality() } (Note the self. before instantiate() which seems to be necessary to get "that" instantiator.) Each subclass knows its own storyboard ID to how use to instantiateViewController : class Dining: Rooms {

问题 This post replies very well to the question "How to get Advertising ID in android?"... but not how to use it. I would like to know what is the parameter to be used in the Google Measurement Protocol to transfer that advertising ID the Google endpoint and get demographic insights in my GA dashboards (on https://analytics.google.com/). Do I have to send it with the client id ("cid")? Or, to make it simple, what is the parameter used by the SDK on iOS and Android? 回答1: If anyone is looking for

问题 I want to get 2 or more different object types on a map easily. Swift 2.0, I wanted to use Protocols. I created a protocol that these object need to conform too. I assume that now any item the conforms to PinProtocol as essentially the same as being an MKAnnotation... just more! protocol PinProtocol: MKAnnotation { // stuff } I have 2 Classes, Staff and Clients Both conform to PinProtocol (which then also needs to conform to MKAnnotation) I know this is working as if I set up my class as such

问题 How can I achieve something like this (doesn't compile): internal protocol InternalPrivateMix { private func doPrivately() internal func doInternaly() } Basically I want to kind of make a promise that confirming class implements some functionality privately. This is more for self documentation. I obviously can just implement these functions in my classes without formally conform to protocol and write documentation describing that every class should implement this functionality. Though it

问题 I am very confused with this kind of stuffs, What should I send as final command, get always confused 8 bits to 1 byte but how do we make it? Is it only the command packet [hex] as shown in screen shot? or Is it header + command packet[hex] shown in two screen shots? Confusion details: In such diagram header block shows mostly like "Bit 7, Bit 6,..,Bit 0" instead of "Bit 0, Bit 1, Bit 2, ... Bit 7", i always wondering why?. But when I apply in code what is following order for byte st[0] = Bit

问题 Suppose I want to transfer just a portion of a file over FTP - is it possible using a standard FTP protocol? In HTTP I could use a Range header in the request to specify the data range of the remote resource. If it's a 1mb file, I could ask for the bytes from 600k to 700k. Is there anything like that in FTP? I am reading the FTP RFC, don't see anything, but want to make sure I'm not missing anything. There's a Restart command in FTP - would that work? Addendum After getting Brian Bondy's

问题 Although HTTP is ubiquitous it comes with its baggage of Headers which in my case is becoming more of a problem. My data to be transferred is an iota of the HTTP header size. Is there another protocol that I can use which is still understood by the browsers and other networks and doesn't come with the baggage of HTTP? Any other way to skip headers and add it at the destination so only a miniscule of data is transferred over the network? 回答1: No. No. Many HTTP headers are optional. A typical