Question

有没有办法在Swift 2.1中实现这个目标

class Apple
{
}

class Fruit
{
    let apples = [Apple]();
}

let fruit = Fruit();

let appleType: AnyClass = Apple.self;
let applesType: Any = fruit.apples.self.dynamicType;

let properties = Mirror(reflecting: fruit).children;
for property in properties
{
    let magicalApples = property.value;

    let array = Array<appleType>(); // creating array of Apple from type

    let apples = magicalApples as! Array<appleType> // typecasting to array of Apple from type
    let moreApples = magicalApples as! applesType // typecasting to [Apple] from type
    let anyApples = magicalApples as! Array<AnyObject> // error SIGABRT, is this a bug?
}

评论的目标会引发错误，＆＃34;使用未声明的类型＆＃34;。

我的目标是知道存储在appleType中的var类型是否可以用作Type

Answer 1

不，你不能指定一个新类型，因为它是一个let Cannot assign to immutable expression of type 'ClassName.Type'

- 更新 -

let anyApples = magicalApples as! Array<AnyObject>应该是 let anyApples = magicalApples as! Array<Any>？

- 更新2 -

查看references

Answer 2

这可以将apples附加到magicalApples。

// Edit: NSObject added
class baseApple: NSObject
{
    required override init()
    {

    }
}

class Apple: baseApple
{

}

// Edit: NSObject added
class Fruit: NSObject
{
    var apples: [Apple] = [Apple]();
}

let fruit = Fruit();

let appleType: baseApple.Type = Apple.self;

let properties = Mirror(reflecting: fruit).children;
for property in properties
{
    let magicalApples = property.value
    var apples = magicalApples as! NSArray as Array<AnyObject> // first typecast to NSArray
    apples.append(appleType.init()) // apples are now edible
    // Edit
    fruit.setValue(apples, forKey: "apples"); // apples supplied, of course I am assuming fruit object will be obtained dynamically.
}

fruit.apples.count; // output: 1

以上适用于这种情况。尽管如此，答案是不可能使用Swift 2.1＆＃39;

This解释了这一点，感谢@DevAndArtist提供的链接。

来自AnyClass或dynamicType，Swift的数组

2 个答案: