使用 GKRandomSource 生成随机数

Question

我在一个结构中使用GKRandomSource 在视图中返回一个随机的励志名言。有没有办法返回该随机数并省略先前的条目？这样用户就不会连续两次收到相同的报价。

let inspiration = [
    "You are looking rather nice today, as always.",
    "Hello gorgeous!",
    "You rock, don't ever change!",
    "Your hair is looking on fleek today!",
    "That smile.",
    "Somebody woke up on the right side of bed!"]

func getRandomInspiration() -> String {
    let randomNumber = GKRandomSource.sharedRandom().nextIntWithUpperBound(inspiration.count)
    return inspiration[randomNumber]
}

Answer 1

为避免生成相同的报价，请跟踪名为lastQuote 的struct 属性中的最后一个报价。然后将最大随机数减1，如果生成的和lastQuote一样，就改用max。

struct RandomQuote {
    let inspiration = [
        "You are looking rather nice today, as always.",
        "Hello gorgeous!",
        "You rock, don't ever change!",
        "Your hair is looking on fleek today!",
        "That smile.",
        "Somebody woke up on the right side of bed!"]

    var lastQuote = 0

    mutating func getRandomInspiration() -> String {
        let max = inspiration.count - 1
        // Swift 3
        // var randomNumber = GKRandomSource.sharedRandom().nextInt(upperBound: max)
        var randomNumber = GKRandomSource.sharedRandom().nextIntWithUpperBound(max)
        if randomNumber == lastQuote {
            randomNumber = max
        }
        lastQuote = randomNumber
        return inspiration[randomNumber]
    }
}

var rq = RandomQuote()
for _ in 1...10 {
    print(rq.getRandomInspiration())
}