Unresolved Reference: findViewById in Kotlin

user_7062709 0
Viewed 33336
fun Tryouts() {
var CheckBox1 : CheckBox = findViewById(R.id.ForwardBox) as CheckBox
CheckBox1.setChecked(false)
}

I'm still a beginner in Kotlin having learnt only the basic working of kotlin, I am unable refer to any android widget or change it's state in Android Studio whether it's TextView or CheckBox or RadioBox.
Same Unresolved Reference errors for findViewById in all cases...
I don't know what is it that I am doing wrong, even java conversion outputs the same errors.

kotlin android
8 Answers

I have faced exactly the same issue, the problem is they have upgraded everything to view binding , Try to use it as a private function inside your main class class MainActivity : AppCompatActivity() - there it worked for me.

user_117224430

I had that same problem, the cause was that I accidentally declared the function outside the class, where the findViewById method from AppCompatActivity is not available.

Moved it back into the scope of the class and the referenced resolved.

user_28892620

am an android newbie for me the below change resolved the issue.

var CheckBox1 = findViewById<CheckBox>(R.id.ForwardBox)

user_33953300

In the new version of kotlin and/or android studio, I just did:

plugins {
    id 'com.android.application'
    id 'kotlin-android'
    id 'kotlin-android-extensions'
}

(at the top of the build.gradle [Module] file)

Then I returned to my activity code and wrote my button name (btn_search) and android studio got the reference done

import kotlinx.android.synthetic.main.activity_main.*
user_67325250
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