Android中RxKotlin是否依赖RxJava？能否单独使用RxKotlin+RxAndroid？

Great question! Let's break this down clearly for your Android dev workflow:

1. Does RxKotlin depend on RxJava? #

Absolutely. RxKotlin is fundamentally a Kotlin extension library for RxJava — it doesn't have its own standalone reactive implementation. It adds Kotlin-specific conveniences like extension functions, lambda simplifications, and better interoperability with Kotlin's standard library, but all of its functionality builds directly on top of RxJava's core reactive streams engine. You can't use RxKotlin without having RxJava in your project.

2. Can you use RxKotlin + RxAndroid without adding RxJava separately? #

Nope, that's not possible. Here's why:

• RxAndroid is also an extension library, built for Android platform-specific use cases (like the AndroidSchedulers.mainThread() scheduler for UI updates) and it directly depends on RxJava.
• Since both RxKotlin and RxAndroid rely on RxJava as their underlying core, you must include RxJava in your project first. Even if you only declare RxKotlin and RxAndroid in your build.gradle, your build system will still pull in RxJava as a transitive dependency — but it's always better to explicitly declare the RxJava version you want to use to avoid version conflicts.

Example Gradle Dependencies (for RxJava 3) #

To use all three together, your dependencies would look something like this:

// Explicitly declare RxJava core (recommended for version control)
implementation 'io.reactivex.rxjava3:rxjava:3.1.8'
// RxKotlin (matches RxJava 3 version)
implementation 'io.reactivex.rxjava3:rxkotlin:3.0.1'
// RxAndroid (matches RxJava 3 version)
implementation 'io.reactivex.rxjava3:rxandroid:3.0.2'

In short: RxJava is the foundational layer, RxKotlin makes it Kotlin-friendly, and RxAndroid adds Android-specific tools. You can't skip RxJava when using the other two.

内容的提问来源于stack exchange，提问作者Hafiz Waleed Hussain