method-swizzling

来源： https://stackoverflow.com/questions/53188675/ios-swizzle-better-understanding

问题 I am trying to swizzle UIImage.init(named:) but the init is not being called extension UIImage { @objc public convenience init?(swizzledName: String) { self.init(named: swizzledName) /// Do something print("this is working") } static func swizzle() { guard let instance = class_getClassMethod(self, #selector(UIImage.init(named:))), let swizzledInstance = class_getClassMethod(self, #selector(UIImage.init(swizzledName:))) else { return } method_exchangeImplementations(instance, swizzledInstance)

问题 I am trying to swizzle UIImage.init(named:) but the init is not being called extension UIImage { @objc public convenience init?(swizzledName: String) { self.init(named: swizzledName) /// Do something print("this is working") } static func swizzle() { guard let instance = class_getClassMethod(self, #selector(UIImage.init(named:))), let swizzledInstance = class_getClassMethod(self, #selector(UIImage.init(swizzledName:))) else { return } method_exchangeImplementations(instance, swizzledInstance)

问题 Currently experimenting with method swizzling in Objective-C and I have a question. I am trying to understand the proper way to method swizzle and after researching online I stumbled upon this NSHipster post: http://nshipster.com/method-swizzling/ In the post the author has some method swizzling sample code. I am looking for someone to better explain to me what the author is doing.. In particular I am confused on the didAddMethod logic. Why is the author not just directly swapping/exchanging

问题 Currently experimenting with method swizzling in Objective-C and I have a question. I am trying to understand the proper way to method swizzle and after researching online I stumbled upon this NSHipster post: http://nshipster.com/method-swizzling/ In the post the author has some method swizzling sample code. I am looking for someone to better explain to me what the author is doing.. In particular I am confused on the didAddMethod logic. Why is the author not just directly swapping/exchanging

问题 I'm essentially looking for a way to detect when/what third party libraries swizzle. I recently ran into a situation where an ad library used an oddball fork of AFNetworking. AFNetworking swizzles NSURLSessionTask, and the two swizzles didn't play nicely under certain circumstances. I'd really like to be able to detect and sanity check this kind of thing, and ideally even keep a versioned dump of every swizzled method in the app so we have some visibility into who's monkey patching what and

问题 I try to figure out how things really work. So I thought when I would overwrite certain methods using categories, I would get interesting NSLogs. @implementation UIView(Learning) - (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event { NSLog(@"-hitTest:withEvent: event=%@", event); return [self hitTest:point withEvent:event]; } @end super and self don't work here. Is there a way to call the original implementation of -hitTest:withEvent:? What I want is an NSLog every time -hitTest

问题 This question already has answers here : Swift 3.1 deprecates initialize(). How can I achieve the same thing? (9 answers) Closed 2 years ago . Swizzling in Swift 4 no longer works. Method 'initialize()' defines Objective-C class method 'initialize', which is not permitted by Swift This is something I have found a solution to so wanted to leave the questions and answer for others. 回答1: initialize() is no longer exposed: Method 'initialize()' defines Objective-C class method 'initialize', which

问题 I'm trying to swizzle NSMutableDictionary. What am I doing wrong here? I'm trying to override setObject:forKey: for NSMutableDictionary. #import "NSMutableDictionary+NilHandled.h" #import <objc/runtime.h> @implementation NSMutableDictionary (NilHandled) + (void)load{ static dispatch_once_t onceToken; dispatch_once(&onceToken, ^{ Class class = [self class]; SEL originalSelector = @selector(setObject:forKey:); SEL swizzledSelector = @selector(swizzledSetObject:forKey:); Method originalMethod =

问题 I would like to make use of method swizzling, but am unable to get even simple examples to work for me. It is possible that I am misunderstanding what the concept is, but as far as I know it allows for method implementations to be swapped. Given two methods, A and B, I would like to swap their implementations such that calling A would execute B instead. I came across a few examples of swizzling (example1 and example2). I created a new project with a class to test this. class Swizzle: NSObject