如何检查是否有“lateinit"变量是否已初始化? [英] How to check if a "lateinit" variable has been initialized?

问题描述

我想知道是否有办法检查 lateinit 变量是否已初始化.例如:

I wonder if there is a way to check if a lateinit variable has been initialized. For example:

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
    }
}

推荐答案

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:

There is a lateinit improvement in Kotlin 1.2 that allows to check the initialization state of lateinit variable directly:

lateinit var file: File    

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

请参阅 JetBrains 博客上的公告 或 KEEP 提案.

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

UPDATE: Kotlin 1.2 has been released. You can find lateinit enhancements here:

• 检查是否为 lateinit var初始化
• Lateinit 顶级属性和局部变量

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