如何将属性获取器作为函数类型传递给另一个函数 [英] How can I pass property getter as a function type to another function

问题描述

如何将属性获取器传递给接受函数类型的函数?

How can I pass property getter to a function that accepts function type?

以下是我想要实现的示例:

Here is an example of what I want achieve:

class Test {
    val test: String
        get() = "lol"

    fun testFun(func: ()->String) {
        // invoke it here
    }

    fun callTest() {
        testFun(test::get) 
        // error: Type mismatch: inferred type is 
        // KFunction1<@ParameterName Int, Char> but () -> String was expected
    }
}

有办法吗?

推荐答案

您可以通过编写::test(或this::test)来引用吸气剂.

You can reference the getter by writing ::test (or this::test).

编写test::get时，实际上是在String上引用get方法.该方法获取一个索引并返回该索引处的字符.

When you write test::get, you are actually referencing the get method on String. That method takes an index and returns the character at that index.

如果该属性是var，并且您想要引用其setter，则可以编写::test::set.

If the property was a var and you want a reference to its setter, you can write ::test::set.

有关属性引用的更多信息，请参见此处: https://kotlinlang.org/docs/reference/reflection.html#bound-function-and-property-references-since-11

For more info on property references, see here: https://kotlinlang.org/docs/reference/reflection.html#bound-function-and-property-references-since-11

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