Kotlin反射案例多不多

小樊
81
2024-11-03 02:59:43

Kotlin 反射案例的數(shù)量相對(duì)較少,但Kotlin 提供了強(qiáng)大的反射庫(kù),可以讓你在運(yùn)行時(shí)檢查和操作類、對(duì)象、接口、函數(shù)等元素。以下是一些常見(jiàn)的 Kotlin 反射案例:

  1. 獲取類的元數(shù)據(jù):
import kotlin.reflect.KClass
import kotlin.reflect.full.declaredFunctions
import kotlin.reflect.full.memberFunctions
import kotlin.reflect.jvm.kotlinFunction

fun main() {
    val kClass: KClass<String> = String::class
    println("類名: ${kClass.qualifiedName}")
    println("構(gòu)造函數(shù): ${kClass.primaryConstructor?.name}")
    println("屬性: ${kClass.declaredProperties.joinToString { it.name } }")
    println("方法: ${kClass.memberFunctions.joinToString { it.name } }")
}
  1. 調(diào)用類的函數(shù):
import kotlin.reflect.KFunction
import kotlin.reflect.full.callSuspendFunction
import kotlin.reflect.jvm.kotlinFunction

fun main() {
    val kClass: KClass<String> = String::class
    val function: KFunction<*> = kClass.memberFunctions.first { it.name == "plus" }
    val instance = "Hello"
    val result = function.callSuspendFunction(instance, " World")
    println("調(diào)用結(jié)果: $result")
}
  1. 創(chuàng)建類的實(shí)例:
import kotlin.reflect.KClass
import kotlin.reflect.jvm.kotlinFunction

fun main() {
    val kClass: KClass<String> = String::class
    val constructor: KFunction<*> = kClass.primaryConstructor
    val instance = constructor.call()
    println("創(chuàng)建實(shí)例: $instance")
}
  1. 修改類的屬性值:
import kotlin.reflect.KClass
import kotlin.reflect.full.declaredProperties
import kotlin.reflect.jvm.kotlinProperty

fun main() {
    val kClass: KClass<String> = String::class
    val properties = kClass.declaredProperties
    properties.forEach { property ->
        if (property.name == "length") {
            val getter = property.getter
            val value = getter.call(null) as Int
            println("原長(zhǎng)度: $value")

            val setter = property.setter
            setter.call(value + 1)
            println("新長(zhǎng)度: ${property.getter.call(null)}")
        }
    }
}

這些案例展示了 Kotlin 反射的基本用法。你可以根據(jù)自己的需求進(jìn)行擴(kuò)展和深入挖掘。

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