斯威夫特5:

方式1:

print("Class: \(String(describing: self)), Function: \(#function), line: \(#line)")

输出:

Class: <Test.ViewController: 0x7ffaabc0a3d0>, Function: viewDidLoad(), line: 15

方式2:

print("Class: \(String(describing: type(of: self))), Function: \(#function), line: \(#line)")

输出:

Class: ViewController, Function: viewDidLoad(), line: 16

更新到swift 5

我们可以通过String初始化器使用实例变量获得类型名的详细描述，并创建某个类的新对象

例如，print(String(description: type(of: object)))。其中object可以是一个实例变量，如数组，字典，Int, NSDate等。

因为NSObject是大多数Objective-C类层次结构的根类，你可以尝试为NSObject做一个扩展，以获得NSObject的每个子类的类名。是这样的:

extension NSObject {
    var theClassName: String {
        return NSStringFromClass(type(of: self))
    }
}

或者您可以创建一个静态函数，其参数类型为Any(所有类型隐式遵循的协议)，并将类名返回为String。是这样的:

class Utility{
    class func classNameAsString(_ obj: Any) -> String {
        //prints more readable results for dictionaries, arrays, Int, etc
        return String(describing: type(of: obj))
    }
} 

现在你可以这样做:

class ClassOne : UIViewController{ /* some code here */ }
class ClassTwo : ClassOne{ /* some code here */ }

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

        // Get the class name as String
        let dictionary: [String: CGFloat] = [:]
        let array: [Int] = []
        let int = 9
        let numFloat: CGFloat = 3.0
        let numDouble: Double = 1.0
        let classOne = ClassOne()
        let classTwo: ClassTwo? = ClassTwo()
        let now = NSDate()
        let lbl = UILabel()

        print("dictionary: [String: CGFloat] = [:] -> \(Utility.classNameAsString(dictionary))")
        print("array: [Int] = [] -> \(Utility.classNameAsString(array))")
        print("int = 9 -> \(Utility.classNameAsString(int))")
        print("numFloat: CGFloat = 3.0 -> \(Utility.classNameAsString(numFloat))")
        print("numDouble: Double = 1.0 -> \(Utility.classNameAsString(numDouble))")
        print("classOne = ClassOne() -> \((ClassOne).self)") //we use the Extension
        if classTwo != nil {
            print("classTwo: ClassTwo? = ClassTwo() -> \(Utility.classNameAsString(classTwo!))") //now we can use a Forced-Value Expression and unwrap the value
        }
        print("now = Date() -> \(Utility.classNameAsString(now))")
        print("lbl = UILabel() -> \(String(describing: type(of: lbl)))") // we use the String initializer directly

    }
}

而且，一旦我们可以获得类名String，我们就可以实例化该类的新对象:

// Instantiate a class from a String
print("\nInstantiate a class from a String")
let aClassName = classOne.theClassName
let aClassType = NSClassFromString(aClassName) as! NSObject.Type
let instance = aClassType.init() // we create a new object
print(String(cString: class_getName(type(of: instance))))
print(instance.self is ClassOne)

也许这能帮助一些人!

有时其他解决方案会给出一个无用的名称，这取决于您试图查看的对象。在这种情况下，您可以使用以下命令获取类名作为字符串。

String(cString: object_getClassName(Any!))

⌘单击xcode中的函数，查看一些相当有用的相关方法。或者点击这里查看https://developer.apple.com/reference/objectivec/objective_c_functions

在Swift 4.1和现在的Swift 4.2中:

import Foundation

class SomeClass {
    class InnerClass {
        let foo: Int

        init(foo: Int) {
            self.foo = foo
        }
    }

    let foo: Int

    init(foo: Int) {
        self.foo = foo
    }
}

class AnotherClass : NSObject {
    let foo: Int

    init(foo: Int) {
        self.foo = foo
        super.init()
    }
}

struct SomeStruct {
    let bar: Int

    init(bar: Int) {
        self.bar = bar
    }
}

let c = SomeClass(foo: 42)
let s = SomeStruct(bar: 1337)
let i = SomeClass.InnerClass(foo: 2018)
let a = AnotherClass(foo: 1<<8)

如果你周围没有实例:

String(describing: SomeClass.self) // Result: SomeClass
String(describing: SomeStruct.self) // Result: SomeStruct
String(describing: SomeClass.InnerClass.self) // Result: InnerClass
String(describing: AnotherClass.self) // Result: AnotherClass

如果你有一个实例:

String(describing: type(of: c)) // Result: SomeClass
String(describing: type(of: s)) // Result: SomeStruct
String(describing: type(of: i)) // Result: InnerClass
String(describing: type(of: a)) // Result: AnotherClass

斯威夫特3.0: 你可以创建一个像这样的扩展..它返回的是类名，而不是项目名

extension NSObject {
    var className: String {
        return NSStringFromClass(self as! AnyClass).components(separatedBy: ".").last ?? ""
    }

    public class var className: String {
        return NSStringFromClass(self).components(separatedBy: ".").last ?? ""
    }
}

斯威夫特3.0

字符串(描述:MyViewController.self)