kotlin - Rx Java，subscribe({}) 与 subscribe { } 有什么区别？

Question

Observable.just(10,20,30,40,50)
            .subscribe { Consumer<Int>{
                Log.d(TAG, "Where I'm I" + Thread.currentThread())
                System.out.println("Hello boss")
                Toast.makeText(baseContext.applicationContext, "Hellloo",Toast.LENGTH_SHORT).show()
            } }

对比

 Observable.just(10,20,30,40,50)
            .subscribe( { Consumer<Int>{
                Log.d(TAG, "Where I'm I" + Thread.currentThread())
                System.out.println("Hello boss")
                Toast.makeText(baseContext.applicationContext, "Hellloo",Toast.LENGTH_SHORT).show()
            } })

调用 subscribe({}) 与 subscribe { } 之间有什么区别

Answer 1

对于RxJava来说没有区别。调用和执行保持不变。它只是 kotlin 中的一种特殊语法，称为 trailing lambda。

在 kotlin 中，如果您有一个以 lambda 作为最后一个参数的函数，那么您可以将该 lambda 移出括号。如果 lambda 是唯一参数，那么您也可以删除括号。

来自kotlin docs

Passing trailing lambdas

In Kotlin, there is a convention: if the last parameter of a function is a function, then a lambda expression passed as the corresponding argument can be placed outside the parentheses:

// Second argument of fold is of function type,
// hence we have moved the lambda out of parentheses.
val product = items.fold(1) { acc, e -> acc * e }

Such syntax is also known as trailing lambda.

If the lambda is the only argument to that call, the parentheses can be omitted entirely:

// run only takes a single argument of function type,
// hence we have omitted the parentheses.
run { println("...") }