objective-c - 如何将此代码从 objective-c 更改为 swift？

Question

如何将此代码从 objective-c 更改为 swift :

- (void)get_answer_dict:(NSDictionary *)dict_1:(NSDictionary *)dict_2{

}

我写信给:

func get_answer_dict(dict_1: [NSObject: AnyObject], dict_2: [NSObject: AnyObject])
    {

    }

但不行......

//错误输出

2016-05-28 10:09:23.815 Meet Design[32299:919087] -[Meet_Design.DesignerScroll get_answer_dict::]: unrecognized selector sent to instance 0x7ffa8af32670
2016-05-28 10:09:23.825 Meet Design[32299:919087] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[Meet_Design.DesignerScroll get_answer_dict::]: unrecognized selector sent to instance 0x7ffa8af32670'
*** First throw call stack:
(
    0   CoreFoundation                      0x000000010c67fd85 __exceptionPreprocess + 165
    1   libobjc.A.dylib                     0x000000010bd44deb objc_exception_throw + 48
    2   CoreFoundation                      0x000000010c688d3d -[NSObject(NSObject) doesNotRecognizeSelector:] + 205
    3   CoreFoundation                      0x000000010c5cecfa ___forwarding___ + 970

Answer 1

您的 Objective-C 方法声明使用的是不带命名参数的方法签名样式，我们通常不再使用这种样式。你会喜欢那种风格，还是会使用更现代的风格？但是如果你真的想实现一个没有命名参数的 Swift 方法，它会是这样的:

func get_answer_dict(dict_1: [NSObject: AnyObject]!, _ dict_2: [NSObject: AnyObject]) {
   ...
}

然后您可以从 Swift 调用它:

obj.get_answer_dict(dictionary1, dictionary2)

或者来自 Objective-C:

[obj get_answer_dict:dictionary1 :dictionary2];

---

话虽如此，我衷心鼓励您使用更传统的方法命名约定，例如。

- (void)retrieveAnswerWithDictionary1:(NSDictionary *)dictionary1 dictionary2:(NSDictionary *)dictionary2 {
    ....
}

你会称之为

[obj retrieveAnswerWithDictionary1:someDictionary dictionary2:someOtherDictionary];

Swift 等价物是:

func retrieveAnswerWithDictionary1(dictionary1: [NSObject: AnyObject], dictionary2: [NSObject: AnyObject]) {
    ...
}

这将被称为:

obj.retrieveAnswerWithDictionary1(someDictionary, dictionary2: someOtherDictionary)

请注意，不仅是参数命名，而且我使用驼峰命名约定并且没有下划线。

坦率地说，我也会更具体地向字典输入键和值类型，但我会把它留给你。 Swift 的主要优点之一是它比 Objective-C 更重视类型安全，因此除非万不得已，否则我们通常不会使用 NSObject 或 AnyObject。