如何从科罗廷·科特林那里获得价值？

Question

我有一个用户登录的函数。但它被暂停了。我试着获取它的返回值，但我做不到。这就是我想做的

代码

class LoginViewModel @ViewModelInject constructor(private val remoteDataSource: OrderRemoteDataSource) :
    ViewModel() {

    private fun areValidCredentials(username: String?, password: String?): Boolean {
        return username != null && password != null && username.length > 4 && password.length > 4
    }

    suspend fun login(username: String?, password: String?): Boolean {
        return suspendCoroutine { it ->
            val valid = areValidCredentials(username, password)
            if (valid) {
                // call finish so login activity won't show up after back button clicked in home fragment
                try {
                    viewModelScope.launch {
                        //TODO CHECK if error code
                        val loginResponse =
                            remoteDataSource.login(LoginRequest(username!!, password!!))
                        if (loginResponse.status == Resource.Status.SUCCESS) {
                            val jwtToken = loginResponse.data?.jwtToken
                            if (!jwtToken.isNullOrEmpty()) {
                                sessionManager.saveAuthToken(jwtToken!!)
                                //ERROR!
                                it.resume(true)
                            }

                        }
                    }
                } catch (e: Exception) {
                    Log.i("[LoginActivity]", e.localizedMessage!!)
                    it.resume(false)
                    e.printStackTrace()
                }
            } else {
                Toast.makeText(
                    LOGIN_ACTIVITY,
                    "Username and password must be at least 5 letters long",
                    Toast.LENGTH_SHORT
                ).show()
            }
            it.resume(false)
        }
    }
}

我称之为

@AndroidEntryPoint
class LoginFragment : Fragment() {
    private val mViewModel: LoginViewModel by viewModels()
    private lateinit var navController: NavController

    override fun onCreateView(
        inflater: LayoutInflater, container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View {
        return inflater.inflate(R.layout.frg_login, container, false)
    }

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        Log.d("[LoginFragment]", "onCreate fun started!")

    }

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)

        navController = findNavController()
        loginButton.setOnClickListener {
            //TODO navigate to new fragmnet
            lifecycleScope.launch {
                mViewModel.login(
                    loginUsernameText.text.toString(),
                    loginPasswordText.text.toString()
                )
            }
        }
    }

我有错误

E/AndroidRuntime：致命异常：主进程:ru.gkomega.navigation，pid:11863java.lang.IllegalStateException：已在kotlin.coroutines.safeContinuation.ResumeWith(safeContinuationJVM.kt:45)在ru.gkomega.maumarket.ui.login.loginviewModel$login$$inlined$suspendCoroutines.jvm.internal.baseContinuationImpl.ResumeWith(continuationImpl.kt:33)在uest对不可优化的方法java.lang.Class java.lang.Class.ClassForName（java.lang.String,boolean,java.lang.ClassLoader）I/process：发送信号。PID：11863 SIG:9与目标VM断开连接，地址：“localhost:58264"，传输：”socket“

我不是很了解coroutine，所以它们可能是问题所在

Answer 1

无论请求是否发生，是否失败，您都将恢复协调线。

suspend fun login(username: String?, password: String?): Boolean = suspendCoroutine { cont ->
    if (areValidCredentials(username, password)) {
        try {
            viewModelScope.launch {
                val loginResponse = remoteDataSource.login(LoginRequest(username!!, password!!))
                val jwtToken = loginResponse.data?.jwtToken
                if (loginResponse.status == Resource.Status.SUCCESS && !jwtToken.isNullOrEmpty()) {
                    sessionManager.saveAuthToken(jwtToken!!)
                    cont.resume(true)
                } else cont.resume(false)  // <-- Don't forget
            }
        } catch (e: Exception) {
            Log.i("[LoginActivity]", e.localizedMessage!!)
            cont.resume(false)
            e.printStackTrace()
        }
    } else {
        Toast.makeText(
            LOGIN_ACTIVITY,
            "Username and password must be at least 5 letters long",
            Toast.LENGTH_SHORT
        ).show()
        cont.resume(false)  // <-- Put it right here.
    }
    // cont.resume(false)  // <-- Not here
}