Question

我已经编写了适合我需要的扩展功能：

suspend fun AsyncLayoutInflater.inflateSuspended(@LayoutRes resid: Int, parent: ViewGroup?): View {
    return suspendCoroutine { continuation ->
        inflate(resid, parent) { view, _, parent ->
            continuation.resume(view)
        }
    }
}

但是我不确定如何在不阻止UI的情况下使用它。我尝试了Dispatchers.IO，但出现了 RuntimeException：无法在未调用Looper.prepare（）

的线程内创建处理程序

我应该如何使用此功能？

更新：我发现inflate不会冻结UI，而addView会冻结。 calendarHolder在ScrollView内部。在屏幕上显示calendarView之前，滚动定格。

val inflater = AsyncLayoutInflater(this)

val startTime = System.currentTimeMillis()
coroutineScope.launch {
    val startTimeInside = System.currentTimeMillis()
    repeat(100) {
        calendarView = inflater.inflateSuspended(R.layout.layout_calendar, calendarHolder)
                as MaterialCalendarView
    }

    val addViewStart = System.currentTimeMillis()
    calendarHolder.addView(calendarView)

    val endTimeInside = System.currentTimeMillis()

    Timber.i("inflate: ${endTimeInside - startTimeInside}")
    Timber.i("addView: ${endTimeInside - addViewStart}")

    setupCalendar()
}

val endTime = System.currentTimeMillis()

Timber.i("outside: ${endTime - startTime}")

即使日志显示以下内容：

外部：2 充气：2105 addView：5

Answer 1

就像我在评论中提到的那样，AsyncLayoutInflater根据定义是异步的，并且是在主线程中创建实例所必需的，这就是为什么更改Dispatcher时会出错的原因。不过，可以将回调样式转换为协程样式。

示例：已更新以显示协程的组成

class MainActivity : AppCompatActivity(), CoroutineScope {

    private val activityJob = Job()
    private lateinit var requestQueue: RequestQueue

    override val coroutineContext: CoroutineContext
        get() = Dispatchers.Main + activityJob

    suspend fun AsyncLayoutInflater.inflate(@LayoutRes resid: Int, parent: ViewGroup?): View =
        suspendCoroutine { continuation -> inflate(resid, parent) { view, _, _ -> continuation.resume(view) } }

    suspend fun getTodo(id: Int): String = suspendCoroutine { continuation ->
        val request =  StringRequest(Request.Method.GET, "https://jsonplaceholder.typicode.com/todos/$id",
            Response.Listener { continuation.resume(it) },
            Response.ErrorListener { continuation.resumeWithException(it) }
        )
        requestQueue.add(request)
    }

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        requestQueue = Volley.newRequestQueue(this)

        val parent = findViewById<ViewGroup>(R.id.frameLayout)
        val asyncLayoutInflater = AsyncLayoutInflater(this)

        launch {
            val view = asyncLayoutInflater.inflate(R.layout.async_layout, parent) as TextView
            parent.addView(view)

            delay(1000)

            val todo = getTodo(1)
            view.text = todo
        }
    }

    override fun onDestroy() {
        super.onDestroy()
        activityJob.cancel()
        requestQueue.cancelAll { true }
    }
}

More information

如何在Kotlin协程中使用AsyncLayoutInflater而不阻塞UI

1 个答案: