Button 主要活动不包括'；我无法识别活动_main（布局）（kotlin）（已修复）中的项目。您可以查看我的评论以获得答案

我无法让android studio识别我的emailtext，下面的passwordtext是我的布局和主要活动代码

    package com.example.fotografpaylasmafirebase
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.view.View
import com.google.firebase.auth.FirebaseAuth

class KullaniciActivity : AppCompatActivity() {
   private lateinit var auth : FirebaseAuth
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        auth = FirebaseAuth.getInstance()
    }

**这是有问题的部分emailText.text.toString（）和passwordText.text.toString（）无法识别**

  fun girisYap(view: View){
    }
    fun kayitOl(view: View){
        val email = emailText.text.toString()
        val sifre = passwordText.text.toString()
    }
}

这里是布局代码，文本有其id，但mainActivity仍然无法识别它们

  <?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".KullaniciActivity">

    <EditText
        android:id="@+id/emailText"
        android:layout_width="255dp"
        android:layout_height="97dp"
        android:layout_marginStart="75dp"
        android:layout_marginTop="129dp"
        android:layout_marginEnd="75dp"
        android:layout_marginBottom="34dp"
        android:ems="10"
        android:hint="E-mail giriniz."
        android:inputType="textEmailAddress"
        app:layout_constraintBottom_toTopOf="@+id/passwordText"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        android:autofillHints="" />

    <EditText
        android:id="@+id/passwordText"
        android:layout_width="213dp"
        android:layout_height="67dp"
        android:layout_marginBottom="36dp"
        android:ems="10"
        android:hint="Şifre giriniz."
        android:inputType="textPassword"
        app:layout_constraintBottom_toTopOf="@+id/button2"
        app:layout_constraintStart_toStartOf="@+id/emailText"
        app:layout_constraintTop_toBottomOf="@+id/emailText" />

    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="20dp"
        android:onClick="girisYap"
        android:text="Giriş Yap"
        app:layout_constraintBaseline_toBaselineOf="@+id/button2"
        app:layout_constraintEnd_toStartOf="@+id/button2"
        app:layout_constraintStart_toStartOf="parent" />

    <Button
        android:id="@+id/button2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginEnd="20dp"
        android:layout_marginBottom="242dp"
        android:onClick="kayitOl"
        android:text="Kayıt ol"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toEndOf="@+id/button"
        app:layout_constraintTop_toBottomOf="@+id/passwordText" />

</androidx.constraintlayout.widget.ConstraintLayout>

我终于解决了这个问题！你必须在plugins下的build.gradle（：app）中添加id“kotlin android extensions”，最后我解决了这个问题！您必须在plugins下的build.gradle（：app）中添加id“kotlin android extensions”