“#selector”的参数不引用中的初始化程序或方法

Question

我将我的项目从 Swift2.2 更新为 Swift3.0 但是 "Argument of '#selector' does not refer to an initializer or method" 收到了问题。

代码如下 :

for object in Students {
    let sectionNumber = collation.section(for: object.firstName!, collationStringSelector: #selector(NSObjectProtocol.self))
    sections[sections.count - 1 - sectionNumber].append(object)
}

Answer 1

根据文档

func section(for object: Any, collationStringSelector selector: selector) -> Int

Description 
Returns an integer identifying the section in which a model object belongs.
The table-view controller should iterate through all model objects for the table view and call this method for each object. If the application provides a Localizable.strings file for the current language preference, the indexed-collation object localizes each string returned by the method identified by selector. It uses this localized name when collating titles. The controller should use the returned integer to identify a local “section” array in which it should insert object.

Parameters  
object
A model object of the application that is part of the data model for the table view.

*selector*
A selector that identifies a method returning an identifying string for object that is used in collation. The method should take no arguments and return an NSString object. For example, this could be a name property on the object.

Returns 
An integer that identifies the section in which the model object belongs. The numbers returned indicate a sequential ordering.

解决方案

改变如下

collation.section(for: "test", collationStringSelector: #selector(getStr)) //here getStr is an other function returning String



func getStr()->String{
        return "test"; // this should return an identifying string for object that is used in your collation
}

Answer 2

class Person: NSObject {
    @objc var name: String

    init(name: String) {
        self.name = name
    }
}

let p = Person(name: "Alice")

let collation = UILocalizedIndexedCollation.current()
collation.section(for: p, collationStringSelector: #selector(getter: Person.name))

这也很好，因为 Selector 来自 Objective-C。我们需要 :NSObject 和 @objc.

Answer 3

我实施了 user2215977 答案，但应用程序一次又一次崩溃。现在我只需将#selector(NSObjectProtocol.self) 更改为"self"。所有错误都消失了，但只收到一个警告“不推荐使用 Objective-C 选择器的字符串文字；改用#selector”。

如果有人有解决此警告的想法，请立即分享 me.Otherwise 错误。

“#selector”的参数不引用中的初始化程序或方法

Argument of '#selector' does not refer to an initializer or method in

ios

swift3

xcode8.1