Display the version name in Kotlin

Issue

I am planning to display the version code on my xml files but I am have an error to display the text.

My Activity Code

    val displayVersion = findViewById<TextView>(R.id.app_version)
    val appVersion = getString(R.string.app_version)
    val versionName: String = BuildConfig.VERSION_NAME
    displayVersion.text = "$appVersion $versionName"

My XML Code

<TextView
    android:id="@+id/app_version"
    android:layout_below="@+id/splash_progressbar"
    android:layout_width="match_parent"
    android:layout_marginBottom="20dp"
    android:layout_height="wrap_content"
    android:gravity="center_horizontal"
    android:textSize="12sp"
    tools:text="TextView"/>

Error Code

displayVersion.text = "$appVersion $versionName"

Maybe this error code are incorrect, because every-time I that code the app will works if the code exist the app will lunch but eventually it will automatically crash.

Solution

The reason for this error because I put the layout below to the code I provided above

I just put this code above setContentView(R.layout.layout_name)

setContentView(R.layout.layout_name) <-- This is the root cause of my concern
val displayVersion = findViewById<TextView>(R.id.app_version)
val appVersion = getString(R.string.app_version)
val versionName: String = BuildConfig.VERSION_NAME
displayVersion.text = "$appVersion $versionName"

My Error Code

val displayVersion = findViewById<TextView>(R.id.app_version)
val appVersion = getString(R.string.app_version)
val versionName: String = BuildConfig.VERSION_NAME
displayVersion.text = "$appVersion $versionName"
setContentView(R.layout.layout_name) <--This should be put above

Answered By - Clinton Canarias