Kotlin中实现多线程数据刷新的完整方案

// 主线程定义
Handler private val handler = object : Handler(Looper.getMainLooper())
{ 
override fun handleMessage(msg: Message)
{ 
when (msg.what) 
{ 
1 -> textView.text = msg.obj.toString() 
}
}
}
// 子线程发送消息 
thread { val data = fetchData() 
// 耗时操作 
val msg = Message.obtain().apply 
{ 
what = 1 obj = data
} 
handler.sendMessage(msg) 
}

thread 
{
    val result = processData() runOnUiThread
    { 
        textView.text = result 
    } 
}

viewModelScope.launch(Dispatchers.IO)
{ 
    val data = repository.loadData() 
    withContext(Dispatchers.Main) 
    { 
        textView.text = data
    }
    }

fun tickerFlow(period: Duration) = flow 
{
    while (true)
    { 
        emit(Unit) delay(period) 
    } 
} 
// 在ViewModel中触发 viewModelScope.launch 
{ 
    tickerFlow(Duration.seconds(5)) .collectLatest
    { 
        _ -> val newData = fetchData() _uiState.value = UiState.Success(newData) 
    }
    }

class MyViewModel : ViewModel() {
 private val _data = MutableLiveData<String>() 
val data: LiveData<String> = _data 
   fun refresh() {
   viewModelScope.launch(Dispatchers.IO) { 
   val result = fetchData() _data.postValue(result) 
     }
   }
 } 
// Activity中观察
 viewModel.data.observe(this) {
 textView.text = it 
}