[英]Kotlin coroutine async with delay
I'm wrapping my head around the coroutine concept in Kotlin/Android. 我把头放在Kotlin / Android中的协程概念上。 So, as I do not want to use Timertask, Handler with a post delayed I want to use coroutines to execute an async coroutine after a certain delay.
因此,由于我不想使用Timertask,所以处理程序延迟发布,我想使用协程在一定延迟后执行异步协程。 I have the following semi-code:
我有以下半代码:
launch(UI) {
val result = async(CommonPool) {
delay(30000)
executeMethodAfterDelay()
}
result.await()
}
The problem with this is that actually in the async is both method's (delay and executeMethodAfterDelay) are executed at the same time. 问题是实际上在异步中,两个方法(delay和executeMethodAfterDelay)是同时执行的。 While I was expecting that first 30 seconds of delay would be introduced before executeMethodAfterDelay() would be fired.
当我期望在执行executeMethodAfterDelay()之前引入前30秒的延迟。 So my question is, how can I achieve this?
所以我的问题是,我怎样才能做到这一点?
Your code is too convoluted. 您的代码太复杂了。 You need just this:
您只需要这样:
launch(UI) {
delay(30000)
executeMethodAfterDelay()
}
If you specifically want your method to run outside the GUI thread, then write 如果您特别希望您的方法在GUI线程外运行,请编写
launch(CommonPool) {
delay(30000)
executeMethodAfterDelay()
}
More typically you'll want to execute a long-running method off the GUI thread and then apply its result to the GUI. 更典型地,您将需要在GUI线程上执行长时间运行的方法,然后将其结果应用于GUI。 This is how it's done:
这是这样做的:
launch(UI) {
delay(30000)
val result = withContext(CommonPool) {
executeMethodAfterDelay()
}
updateGuiWith(result)
}
Note you don't need async-await
in any scenario. 注意,在任何情况下都不需要
async-await
。
As for your specific report about delay
running concurrently with executeMethodAfterDelay
, this is not actually happening. 至于有关与
executeMethodAfterDelay
并发运行的delay
的特定报告,这实际上并没有发生。 Here's some self-contained code you can try out: 您可以尝试以下一些自包含的代码:
import kotlinx.coroutines.experimental.*
fun main(args: Array<String>) {
runBlocking {
val deferred = async(CommonPool) {
println("Start the delay")
delay(3000)
println("Execute the method")
executeMethodAfterDelay()
}
val result = deferred.await()
println("Method's result: $result")
}
}
fun executeMethodAfterDelay() = "method complete"
This will be the program's behavior: 这将是程序的行为:
Start the delay
... three seconds pass ... ...三秒钟过去了...
Execute the method
Method's result: method complete
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.