lateinit 属性 NotaViewModel 尚未初始化错误

Question

So im trying to do an update in my sqlite data but its giving me error in the viewmodel. Its odd because in my Mainactivity i use one deletebyid and its working just fine, and error occurs when i click in the button, even if i put the notaViewModel.updateNotaByID(id, titulo.toString(), descricao.toString()) like notaViewModel.updateNotaByID(2, "static", "justtosee").

class EditarNota : AppCompatActivity() {

    private lateinit var tituloText: TextView
    private lateinit var descText: TextView
    **private lateinit var notaViewModel: NotaViewModel**
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_new_note)

        tituloText = findViewById(R.id.titulo)
        descText = findViewById(R.id.desc)
        val id=intent.getIntExtra("id",0)
        val tit=intent.getStringExtra("tit")
        val desc=intent.getStringExtra("desc")

        tituloText.text = tit
        descText.text = desc
        val button = findViewById<Button>(R.id.button_save)
        button.setOnClickListener {
            var titulo = tituloText.text
            var descricao = descText.text
            if (id != null) {

                notaViewModel.updateNotaByID(id, titulo.toString(), descricao.toString())
            }

        }
    }
}

Error:

E/AndroidRuntime: FATAL EXCEPTION: main
    Process: ipvc.estg.cmtrabalho, PID: 23245
    kotlin.UninitializedPropertyAccessException: lateinit property notaViewModel has not been initialized
        at ipvc.estg.cmtrabalho.EditarNota.access$getNotaViewModel$p(EditarNota.kt:11)
        at ipvc.estg.cmtrabalho.EditarNota$onCreate$1.onClick(EditarNota.kt:36)
        at android.view.View.performClick(View.java:4780)
        at com.google.android.material.button.MaterialButton.performClick(MaterialButton.java:992)
        at android.view.View$PerformClick.run(View.java:19866)
        at android.os.Handler.handleCallback(Handler.java:739)
        at android.os.Handler.dispatchMessage(Handler.java:95)
        at android.os.Looper.loop(Looper.java:135)
        at android.app.ActivityThread.main(ActivityThread.java:5254)
        at java.lang.reflect.Method.invoke(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:372)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)

Answer 1

You dont need to use lateinit var for viewModel, you can use the 'by viewModels()' Kotlin property delegate

val model: MyViewModel by viewModels()