need
After monitoring the data, create a custom view to draw and display it. Data is sent every 200ms, and custom view data is drawn every 50ms. The original data needs to be smoothed.
1. viewModel side
// Backing property to avoid state updates from other classes
private val _uiState = MutableSharedFlow<Int>(replay = 0)
// The UI collects from this StateFlow to get its state updates
val uiState: SharedFlow<Int> = _uiState
fun sendEvent(event: Int) {
viewModelScope.launch {
_uiState.emit(event)
}
}
Listening end
class FullScreenRhythmActivity : AppCompatActivity(){
override fun onCreate(savedInstanceState: Bundle?) {
...
registerListener(listener)
}
private var listener: Listener = object : Listener() {
// @RequiresApi(Build.VERSION_CODES.O)
override fun onDataEventChanged(eventValue: Value) {
if (GenerateData.isFistEmit) {
Log.d("liulinTest", "startCacheData")
startCacheData(GenerateData.handleOriginalData(value))
GenerateData.isFistEmit = false
} else {
setCacheData(GenerateData.handleOriginalData(value))
}
viewModel.sendEvent(1)
}
}
}
Data processing end
My data is received nearly every 200ms. After the data needs to be cached and smoothed, a set of processed data will be sent out every 50ms and displayed (it will be more time-consuming, so use measureTimeMillis to calculate the time-consuming method)
open class BaseFragment : Fragment() {
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
// 使用lifecycleScope启动协程
// 由于 repeatOnLifecycle 是一个挂起函数，
// 因此从 lifecycleScope 中创建新的协程
viewLifecycleOwner.lifecycleScope.launch {
// 直到 lifecycle 进入 DESTROYED 状态前都将当前协程挂起。
// repeatOnLifecycle 每当生命周期处于 STARTED 或以后的状态时会在新的协程中
// 启动执行代码块，并在生命周期进入 STOPPED 时取消协程。
viewLifecycleOwner.repeatOnLifecycle(Lifecycle.State.STARTED) {
// 每次生命周期处于 STARTED 状态（或更高状态）时，repeatOnLifecycle 在新的协程中启动块，并在它停止时取消它。
viewModel.uiState.collect {
//方法耗时时间
var timeCost =
measureTimeMillis {
...
callback.onChanged(GenerateData.cache1Array!!)
//接收到数据后要做的处理1...
}
if (timeCost < 50)
delay(50 - timeCost)
timeCost =
measureTimeMillis {
...接收到数据后要做的处理2...}
if (timeCost < 50)
delay(50 - timeCost)
timeCost =
measureTimeMillis {
...接收到数据后要做的处理3...}
}
}
}
data processing
object GenerateData {
fun handleOriginalData(byte: ByteArray): MutableList<Int> {
....}
var isFistEmit = true
var cache1Array: FloatArray? = null//缓存数组1
var cache2Array: FloatArray? = null//缓存数组2
var cacheTempArray1: FloatArray? = null
var cacheTempArray2: FloatArray? = null
var cacheTempArray3: FloatArray? = null
fun setCacheData(list: MutableList<Int>) {
...}
fun startCacheData(list: MutableList<Int>) {
..}
}