Kotlin的后期初始化

问题描述

我写了一个用于登录，通过电子邮件和Google登录的代码，但Logcat出现了错误，所以我读了它，这是由于我的代码中初始化过晚造成的，我尝试在溢出中搜索pproblem，但没有找到任何东西

kotlin.UninitializedPropertyAccessException：lateinit属性auth尚未初始化 原因：kotlin.UninitializedPropertyAccessException：lateinit属性auth尚未初始化 在com.example.preludeprototpe.Activity3Kt.access $ getAuth $ p（Activity3.kt：1） 在com.example.preludeprototpe.Activity3.checkLoggedInState（Activity3.kt：96） 在com.example.preludeprototpe.Activity3.onStart（Activity3.kt：48） 在android.app.Instrumentation.callActivityOnStart（Instrumentation.java:1339） 在android.app.Activity.performStart（Activity.java:7167） 在android.app.ActivityThread.performlaunchActivity（ActivityThread.java:2895）

'''

class Activity3 : AppCompatActivity() {
lateinit var auth: FirebaseAuth
private val REQUEST_CODE_SIGN_IN = 0
private val _tag = "Activity3"
override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity3)

    btnlogin2activ3google.setonClickListener {
    val option = GoogleSignInoptions.Builder(GoogleSignInoptions.DEFAULT_SIGN_IN)
        .requestIdToken(getString(R.string.cliendId))
        .requestemail()
        .build()
    val sigInClient = GoogleSignIn.getClient(this,option)
    sigInClient.signInIntent.also {
        startActivityForResult(it,REQUEST_CODE_SIGN_IN)
    }

}
 btnloginactiv3.setonClickListener {
     loginaccount()
 }
}
override fun onStart() {
    super.onStart()
    checkLoggedInState()
}


override fun onActivityResult(requestCode: Int,resultCode: Int,data: Intent?) {
    super.onActivityResult(requestCode,resultCode,data)
    if (requestCode == REQUEST_CODE_SIGN_IN) {
        val account = GoogleSignIn.getSignedInAccountFromIntent(data).result
        account?.let {
            googleaAuthForFirebase(it)
        }
    }
}
private fun googleaAuthForFirebase(account: GoogleSignInAccount) {
    val credential = GoogleAuthProvider.getCredential(account.idToken,null)
    Coroutinescope(dispatchers.IO).launch {
        try {
        auth.signInWithCredential(credential).await()
            withContext(dispatchers.Main) {
                Toast.makeText(this@Activity3,"Success login",Toast.LENGTH_LONG).show()
            }
        }catch (e: Exception){
         withContext(dispatchers.Main) {
             Toast.makeText(this@Activity3,e.message,Toast.LENGTH_LONG).show()
         }
      }
    }
}
private fun loginaccount() {
    val email = etemail.text.toString()
    val password = etpassword.text.toString()
    if(email.isNotEmpty() && password.isNotEmpty()){
        Coroutinescope(dispatchers.IO).launch {
            try {
                auth.signInWithEmailAndPassword(email,password).await()
                withContext(dispatchers.Main){
                    checkLoggedInState()
                    Log.d(_tag,"Activity3")
                }
            }catch (e:Exception){
                withContext(dispatchers.Main){
                    Toast.makeText(this@Activity3,Toast.LENGTH_LONG).show()
                }
            }
        }
    }
}
private fun checkLoggedInState(){
    if(auth.currentUser == null){
        tvLoggedIn.text =  getString(R.string.loggedin)
    }else{
        tvLoggedIn.text = getString(R.string.loggedin2)
    }
}


} 

解决方法

您尚未初始化变量。在onCreate中将其初始化，添加此代码

auth = FirebaseAuth.getInstance()