kotlin - 如何检查 "lateinit"变量是否已初始化？

Question

我想知道是否有办法检查 lateinit 变量是否已初始化。例如:

class Foo() {

    private lateinit var myFile: File

    fun bar(path: String?) {
        path?.let { myFile = File(it) }
    }

    fun bar2() {
        myFile.whateverMethod()
        // May crash since I don't know whether myFile has been initialized
    }
}

Answer 1

在 Kotlin 1.2 中有一个 lateinit 改进，允许直接检查 lateinit 变量的初始化状态:

lateinit var file: File    

if (this::file.isInitialized) { ... }

查看JetBrains blog上的公告或 KEEP proposal .

更新: Kotlin 1.2 已经发布。您可以在此处找到 lateinit 增强功能:

• Checking whether a lateinit var is initialized
• Lateinit top-level properties and local variables