1
private var lastClickTime = 0L
2
fun View.setSingleClickListener(delay: Long = 500, onClick: () -> Unit) {
3
    setOnClickListener {
4
        val currentTime = System.currentTimeMillis()
5
        if (currentTime - lastClickTime > delay) {
6
            onClick()
7
            lastClickTime = currentTime
8
        }
9
    }
10
}

1
fun String.lastChar(): Char = this.get(this.length - 1)
2
---
3
val s = "hello"
4
val c = s.lastChar() // 转化为 StringKt.lastChar(s)