相关疑难解决方法(0)

我正在使用NSArray的是indexOfObjects(passingTest :),但是在我将代码转换为Swift 3之后,我得到了错误:"不明确地使用'indexOfObject(passingTest :)'".我的代码在Swift 2.3下运行良好.

let indexesOfBubbleConstraints = bubbleConstraints.indexesOfObjects(passingTest: { (constraint, idx, stop) in
        if let view = constraint.firstItem as? UIView{
            return view.tag == usernameTag
        }
        else{
            return false
        }
    })

对于斯威夫特3,我也不得不投constraint来AnyObject,但这并不解决实际问题.

我最终使用func indexesOfObjects(options: NSEnumerationOptions = [], passingTest: (Any, Int, UnsafeMutablePointer<ObjCBool>) -> Bool)了一个空数组来获取选项,如下所示.这有效,但我仍然不明白为什么我的原始实现会出现"不明确..."错误.

let indexesOfBubbleConstraints = bubbleConstraints.indexesOfObjects(options: [], passingTest: { (constraint, idx, stop) in
        if let view = (constraint as AnyObject).firstItem as? UIView{
            return view.tag == usernameTag
        }
        else{
            return false
        } …

例如,我有以下课程:

class Person: Any {
    dynamic var name: String = ""
    dynamic var surname: String = ""
}

另外,我有以下数组与"Person"类的实例:

let person1 = Person(); person1.name = "John"; person1.surname = "Smith"
let person2 = Person(); person2.name = "Ivan"; person2.surname = "Ivanov"
let person3 = Person(); person3.name = "Sam"; person3.surname = "Woodman"
let personList = [person1, person2, person3]

有没有办法以某种方式得到所有约翰斯的指数？

我无法在数组中获得可重复的字符串位置.我的代码是这样的:

var startDates : [String] = ["06/11/2018", "16/11/2018", "26/11/2018", "06/11/2018"]
var nomor : [Int] = []
for date in startDates {
        if startDates.contains(where: {
            $0.range(of: "06/11/2018", options: .caseInsensitive) != nil
        }) == true {
            let nomornya = startDates.index(of: "06/11/2018")!
            nomor.append(nomornya)
        }
    }
    print("nomornya:\(nomor)")

结果:

nomornya:[0, 0, 0, 0]

我想这样:

nomornya:[0, 3]

这样做的正确代码是什么？