ios - 随 secret 码生成器 Swift 3？

Question

我正在为 iOS 构建一个随 secret 码生成器。其中，一个按钮生成一个随 secret 码，该密码具有用户选择的特征(例如，切换以打开或关闭小写和大写字母、字符和符号等)。

UI 看起来很棒，其余代码运行顺利，但我无法让我的按钮实际生成随机字母数字字符串。我有一个带有一些占位符文本(“您的密码”)的标签，按下按钮时应该将其文本更新为随机字符串，但我收到编译器错误:“ Unresolved 标识符‘长度’的使用”

这是按钮的当前代码:

@IBAction func generatePassword(_ sender: UIButton) {

    let randomPasswordArray: NSString = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890"
    let len = UInt32(randomPasswordArray.length)

    var randomPassword = ""

    for _ in 0 ..< length {
        let rand = arc4random(len)
        var nextChar = randomPasswordArray.character(at: Int(rand))
        randomPassword += NSString(characters: &nextChar, length: 1) as String
    }

    passwordLabel.text = "randomPassword"
}

谢谢!

Answer 1

首先用你的密码允许的字符创建一个数组

let passwordCharacters = Array("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890".characters)

然后选择密码长度

let len = 8 

定义和空字符串密码

var password = ""

创建一个循环来生成你的随机字符

for _ in 0..<len {
    // generate a random index based on your array of characters count
    let rand = arc4random_uniform(UInt32(passwordCharacters.count))
    // append the random character to your string
    password.append(passwordCharacters[Int(rand)])
}
print(password)   // "V3VPk5LE"

---

swift 4

您还可以使用 map 代替标准循环:

let pswdChars = Array("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890")
let rndPswd = String((0..<len).map{ _ in pswdChars[Int(arc4random_uniform(UInt32(pswdChars.count)))]})
print(rndPswd)   // "oLS1w3bK\n"

swift 4.2

使用新集合的 randomElement() 方法:

let len = 8
let pswdChars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890"
let rndPswd = String((0..<len).compactMap{ _ in pswdChars.randomElement() })
print(rndPswd)   // "3NRQHoiA\n"