I am trying to code my app in Kotlin, but I am getting null cannot be casted to non-null type and app force stops when I open EditNoteActivity at EXTRA_NOTE probably.
如有任何帮助，我们将不胜感激.
Code:
class EditNoteActivity : AppCompatActivity() {
var note: Note? = null
private val editNote: TextView? = null
private val fabdrwble: Boolean? = null
private val notesData: MutableList<Note>? = null
private var databaseHelper: DatabaseHelper? = null
private val save: Boolean? = null
private var saveButton: FloatingActionButton? = null
private val tint: ColorStateList? = null
internal var mRowId: Long? = null
internal var spinner: Spinner? = null
internal var spinnertext: String? = null
internal var fav: Int = 0
internal var mSharedFromIntentFilter = false
internal var editTitle: EditText? = null
internal var editContent: EditText? = null
internal var inputlayoutTitle: TextInputLayout? = null
internal var inputlayoutContent: TextInputLayout? = null
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_edit_note)
var toolbar = findViewById(R.id.toolbar_edit) as Toolbar?
setSupportActionBar(toolbar)
if (supportActionBar != null)
supportActionBar!!.setDisplayHomeAsUpEnabled(true)
databaseHelper = DatabaseHelper(applicationContext)
inputlayoutTitle = findViewById(R.id.inputlayoutTitle) as TextInputLayout?
inputlayoutContent = findViewById(R.id.inputlayoutContent) as TextInputLayout?
editTitle = findViewById(R.id.note_title) as EditText
editContent = findViewById(R.id.note_content) as EditText?
val bundle = intent.extras
val s = bundle.getString("edit")
if (s == "add") {
window.setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_VISIBLE)
} else if (s == "editv") {
window.setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_HIDDEN)
}
note = intent.getSerializableExtra(EXTRA_NOTE) as Note
if (note != null) {
editTitle?.setText(note!!.getTitle())
editContent?.setText(note!!.getContent())
} else {
note = Note()
//note.setUpdatedAt(new Date());
}
saveButton = findViewById(R.id.add_edit_button) as FloatingActionButton?
saveButton!!.setOnClickListener {
if (isNoteFormOk) {
setNoteResult()
finish()
} else
validateNoteForm()
}
var ll = findViewById(R.id.llmain) as LinearLayout?
var ll1 = findViewById(R.id.ll1) as LinearLayout?
/*if(note.getColor() == Color.TRANSPARENT){
selectedColor = preselect;
}else {
selectedColor = note.getColor();
}
getWindow().addFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
systemBarTintManager = new SystemBarTintManager(this);
systemBarTintManager.setStatusBarTintEnabled(true);
ll.setBackgroundColor(selectedColor);
ll1.setBackgroundColor(selectedColor);
toolbar.setBackgroundColor(note.getColor());
systemBarTintManager.setStatusBarTintColor(selectedColor);*/
}
override fun onResume() {
super.onResume()
}
override fun onOptionsItemSelected(item: MenuItem): Boolean {
when (item.itemId) {
android.R.id.home -> {
onBack()
return true
}
/*
case R.id.speech:
try {
displaySpeechRecognizer();
} catch (ActivityNotFoundException e) {
Intent browserIntent = new Intent(Intent.ACTION_VIEW, Uri.parse("https://market.android.com/details?id=com.google.android.googlequicksearchbox"));
startActivity(browserIntent);
}
return true;*/
else -> return super.onOptionsItemSelected(item)
}
}
private fun displaySpeechRecognizer() {
val intent = Intent(RecognizerIntent.ACTION_RECOGNIZE_SPEECH)
intent.putExtra(RecognizerIntent.EXTRA_LANGUAGE_MODEL, RecognizerIntent.LANGUAGE_MODEL_FREE_FORM)
startActivityForResult(intent, SPEECH_REQUEST_CODE)
}
override fun onActivityResult(requestCode: Int, resultCode: Int,
data: Intent) {
if (requestCode == SPEECH_REQUEST_CODE && resultCode == Activity.RESULT_OK) {
val results = data.getStringArrayListExtra(RecognizerIntent.EXTRA_RESULTS)
val spokenText = results[0]
editContent?.setText(spokenText)
}
if (requestCode == RequestResultCode.REQUEST_CODE_ADD_NOTE) {
if (resultCode == Activity.RESULT_OK) {
addNote(data)
}
}
}
private val isNoteFormOk: Boolean
get() {
val title = editTitle?.text.toString()
return !(title == null || title.trim { it <= ' ' }.length == 0)
}
private fun validateNoteForm() {
var msg: String? = null
if (isNullOrBlank(editTitle?.text.toString())) {
msg = "Title Required"
inputlayoutTitle?.error = "Title is Missing"
}
if (msg != null) {
Toast.makeText(applicationContext, msg, Toast.LENGTH_LONG).show()
}
}
private fun setNoteResult() {
note!!.setTitle(editTitle?.text.toString().trim { it <= ' ' })
note!!.setContent(editContent?.text.toString().trim { it <= ' ' })
//note.setUpdatedAt(new Date());
val intent = Intent()
intent.putExtra(EXTRA_NOTE, note)
setResult(Activity.RESULT_OK, intent)
//addNote(intent);
Toast.makeText(this@EditNoteActivity, "Note Saved.", Toast.LENGTH_LONG).show()
}
private fun onBack() {
if (isNoteFormOk) {
if (editTitle?.text.toString() == note!!.getTitle() && editContent?.text.toString() == note!!.getContent()) {
setResult(Activity.RESULT_CANCELED, Intent())
finish()
} else {
AlertDialog.Builder(this@EditNoteActivity)
.setTitle("Save")
.setMessage("Do You Want to Save Note")
.setPositiveButton("SAVE") { dialog, which ->
setNoteResult()
finish()
}.setNegativeButton("CANCEL") { dialog, which ->
setResult(Activity.RESULT_CANCELED, Intent())
finish()
}.show()
}
} else {
setResult(Activity.RESULT_CANCELED, Intent())
finish()
}
}
private fun addNote(data: Intent) {
val note = data.getSerializableExtra(EXTRA_NOTE) as Note
val noteId = databaseHelper!!.createNote(note)
note.setId(noteId)
}
override fun onBackPressed() {
onBack()
val intentHome = Intent(this@EditNoteActivity, MainActivity::class.java)
intentHome.flags = Intent.FLAG_ACTIVITY_CLEAR_TOP
intentHome.putExtra(EXTRA_NOTE, note)
setResult(Activity.RESULT_OK, intentHome)
}
companion object {
private val EXTRA_NOTE = "EXTRA_NOTE"
private val SPEECH_REQUEST_CODE = 0
fun isNullOrBlank(str: String?): Boolean {
return str == null || str.trim { it <= ' ' }.length == 0
}
}
}
Logs:
java.lang.RuntimeException: Unable to start activity ComponentInfo{ com.midsizemango.databasekotlin/com.midsizemango.databasekotlin.EditNoteActivity}: kotlin.TypeCastException: null cannot be cast to non-null type com.midsizemango.databasekotlin.Note at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2298) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360) at android.app.ActivityThread.access$800(ActivityThread.java:144) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278) at android.os.Handler.dispatchMessage(Handler.java:102) at android.os.Looper.loop(Looper.java:135) at android.app.ActivityThread.main(ActivityThread.java:5221) 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:899) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694) Caused by: kotlin.TypeCastException: null cannot be cast to non-null type com.midsizemango.databasekotlin.Note at com.midsizemango.databasekotlin.EditNoteActivity.onCreate(EditNoteActivity.kt:82) at android.app.Activity.performCreate(Activity.java:5933) at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1105) at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2251) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360) at android.app.ActivityThread.access$800(ActivityThread.java:144) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278) at android.os.Handler.dispatchMessage(Handler.java:102) at android.os.Looper.loop(Looper.java:135) at android.app.ActivityThread.main(ActivityThread.java:5221) 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:899) at com.android.internal.os.ZygoteInit.main (ZygoteInit.java:694)