我们如何比较JetPack组合中的TextField值相同的值？

Question

我在Android JetPack组成的登录屏幕上，并且我有ScreenA和ScreenB，在ScreenA中，我有电子邮件，在ScreenB中，我再次有邮件并确认邮件，因此我想控制这三个电子邮件值相同的值。在ScreenA中，当我放任何邮件时，在ScreenB中，两个邮件都必须使用ScreenA，是否有其他解决方案？

screena：

@Composable
fun ScreenA(
    navController: NavController,
    model: MyViewModel
) {

    val email = remember { mutableStateOf(TextFieldValue()) }
  
    Column(
        Modifier
            .fillMaxSize()
        ,
        horizontalAlignment = Alignment.CenterHorizontally
    ) {
        val context = LocalContext.current

  OutlinedTextField(
            value = emailState.value,
            colors = TextFieldDefaults.textFieldColors(
                backgroundColor = white,
                focusedIndicatorColor = Grey,
                unfocusedIndicatorColor = Grey,
                focusedLabelColor = Grey,
                unfocusedLabelColor = Grey,
                cursorColor = custom,
                textColor = custom,

                ),
            onValueChange = { emailState.value = it },
            label = { Text(text = "Email") },
            placeholder = { Text(text = "Email") },
            singleLine = true,
            modifier = Modifier.fillMaxWidth(0.8f)

        )
}

屏幕B：

@Composable
fun ScreenB(

    navController: NavController,
    model: MyViewModel

) {

    val emailState = remember { mutableStateOf(TextFieldValue()) }
    val confirmEmailState = remember { mutableStateOf(TextFieldValue()) }

   Column(
        Modifier.fillMaxSize()  ,
        verticalArrangement = Arrangement.Center,
        horizontalAlignment = Alignment.CenterHorizontally
    ) {


     OutlinedTextField(
            value = emailState.value,
            colors = TextFieldDefaults.textFieldColors(
                backgroundColor = white,
                focusedIndicatorColor = Grey,
                unfocusedIndicatorColor = Grey,
                focusedLabelColor = Grey,
                unfocusedLabelColor = Grey,
                cursorColor = custom,
                textColor = custom,

                ),
            onValueChange = { emailState.value = it },
            label = { Text(text = "E-mail") },
          
            singleLine = true,
            modifier = Modifier.fillMaxWidth(0.8f)

        )

        OutlinedTextField(
            value = confirmEmailState.value,
            colors = TextFieldDefaults.textFieldColors(
                backgroundColor = white,
                focusedIndicatorColor = Grey,
                unfocusedIndicatorColor = Grey,
                focusedLabelColor = Grey,
                unfocusedLabelColor = Grey,
                cursorColor = custom,
                textColor = custom,

                ),
            onValueChange = { confirmEmailState.value = it },
            label = { Text(text = "Confirm E-mail") },
            placeholder = { Text(text = "Confirm E-mail") },
            singleLine = true,
            modifier = Modifier.fillMaxWidth(0.8f)

        )
}

ViewModel：

@HiltViewModel
class MyViewModel @Inject constructor(
    val db: FirebaseFirestore,
    val auth: FirebaseAuth,


) : ViewModel() {

    var singIn = mutableStateOf(false)
    var isInProgress = mutableStateOf(false)
    var popNotification = mutableStateOf<Event<String>?>(null)
    var userData = mutableStateOf<User?>(null)


    init {

        val currentUser = auth.currentUser
        singIn.value = currentUser != null
        currentUser?.uid?.let { uid ->
            getUserData(uid)
        }
    }

    fun onSignOut() {
        auth.signOut()
    }

    fun onSignUp(
        email: String,
        password: String


        ) {
        if (
            email.isEmpty()

        ) {
            handledException(customMessage = "Please fill in all fields")
            return
        }

        isInProgress.value = true

        auth.createUserWithEmailAndPassword(email, password)

            .addOnCompleteListener { task ->
                if (task.isSuccessful) {
                    singIn.value = true

                } else {
                    handledException(customMessage = "signed failed")
                }
                isInProgress.value = false
            }
            .addOnFailureListener {

            }
    }

    fun onSignUpEmail(
      
        emailState: String,
        confirmEmailState: String,

        ) {
        if (
      
            emailState.isEmpty() or
            confirmEmailState.isEmpty()


        ) {
            handledException(customMessage = "Please fill in all fields")
            return
        }

        isInProgress.value = true

        db.collection(USERS).whereEqualTo("email", email.replace(" ", "")).get()
            .addOnSuccessListener { documents ->
                if (documents.size() > 0) {
                    handledException(customMessage = "mail already exist")
                    isInProgress.value = false
                } else {

                    createOrUpdateProfile(
                 
                        emailState = emailState,
                        confirmEmailState = confirmEmailState,

                        )

                    isInProgress.value = false

                }
            }
            .addOnFailureListener { }
    }



    private fun createOrUpdateProfile(

        emailState: String? = null,
        confirmEmailState: String? = null,
      
        ) {
        val uid = auth.currentUser?.uid
        val userData = User(
        
            emailState = emailState ?: userData.value?.emailState,
            confirmEmailState = confirmEmailState ?: userData.value?.confirmEmailState,
  
        )
        uid?.let {
            isInProgress.value = true
            db.collection(USERS).document(uid).get()
                .addOnSuccessListener {
                    if (it.exists()) {
                        it.reference.update(userData.toMap())
                            .addOnSuccessListener {
                                this.userData.value = userData
                                isInProgress.value = false
                            }
                            .addOnFailureListener {
                                handledException(customMessage = "Cannot Update user")
                                isInProgress.value = false

                            }
                    } else {
                        db.collection(USERS).document(uid).set(userData)
                        getUserData(uid)
                        isInProgress.value = false
                    }
                }
                .addOnFailureListener { exception ->
                    handledException(exception, "Cannot create user")
                    isInProgress.value = false
                }
        }
    }

    private fun getUserData(uid: String) {
        isInProgress.value = true
        db.collection(USERS).document(uid).get()
            .addOnSuccessListener {
                val user = it.toObject<User>()
                userData.value = user
                isInProgress.value = false

            }
            .addOnFailureListener { exception ->
                handledException(exception, "Cannot retrieve user data")
                isInProgress.value = false
            }
    }

    fun onLogin(email: String, pass: String) {
        if (email.isEmpty() or pass.isEmpty()) {
            handledException(customMessage = "Please fill in all fields")
            return
        }
        isInProgress.value = true
        auth.signInWithEmailAndPassword(email, pass)
            .addOnCompleteListener { task ->
                if (task.isSuccessful) {
                    singIn.value = true
                    isInProgress.value = false
                    auth.currentUser?.uid?.let { uid ->
//                        handledException(customMessage = "Login success")
                        getUserData(uid)
                    }
                } else {
                    handledException(task.exception, "Login failed")
                    isInProgress.value = false
                }
            }
            .addOnFailureListener { exc ->
                handledException(exc, "Login failed")
                isInProgress.value = false
            }
    }

    private fun handledException(exception: Exception? = null, customMessage: String = "") {
        exception?.printStackTrace()
        val errorMsg = exception?.message ?: ""
        val message = if (customMessage.isEmpty()) {
            errorMsg
        } else {
            "$customMessage: $errorMsg"
        }
        popNotification.value = Event(message)
    }

Answer 1

将电子邮件状态移至您的ViewModel。您也可以将其转换为流，但不是必须的。

在您的ViewModel中看起来好像：

val emailStateA = MutableStateFlow(TextFieldValue())
val emailStateB = MutableStateFlow(TextFieldValue()) 
val areEmailsEqual = MutableStateFlow(true) 
init {
    viewModelScope.launch {
       combine(emailStateA, emailStateB) { a, b -> 
           areEmailsEqual.emit(a == b) }.collect() 
    }       
}