android - Kotlin Flow - 有没有类似于 LiveData 的 emitSource 的东西？

Question

我有一个函数，它接受一个返回 Flow 的参数函数，

fun <T> resultFlow(
  query: () -> Flow<T>,
  ... other parameters
): Flow<T> {
  return flow {

    val source = query()

    //!!!!    emit(source)   // I want something like emitSource like livedata has

   ...
   }

有没有什么可以让flow可以这样发送的？

Answer 1

如果你想从流中发出所有项目，这正是 emitAll()做:

fun <T> resultFlow(
  query: () -> Flow<T>,
  ... other parameters
): Flow<T> {
  return flow {

    val source = query()

    // Note that this will suspend until all values from the flow are collected.
    emitAll(source)
}