在Kotlin中动态更改textView值

Question

I have timed proximity sensors changes as

 override fun onSensorChanged(event: SensorEvent) {
       val distance = event.values[0]
       val max = event.sensor.maximumRange
       a = System.currentTimeMillis()
    if (distance < Math.min(max, 8.toFloat())) {
        listener.onNear()
    } else {
        listener.onFar()
    }

        b = System.currentTimeMillis()
    System.out.println("That took " + (b- a) + " milliseconds")
}

which is present in my ProximityDetector.kt file

and displaying it on my App using

timeTaken.setText("That took " + (b - a) + " milliseconds")

which is in my SettingsActivity.kt file

But it shows values for only one sensor change, for subsequent sensor changes the app needs to be withdrawn and opened again. How to display the values for each sensor change??? I tried using this way

override fun onSensorChanged(event: SensorEvent) {
    timeTaken.setText("That took " + (b - a) + " milliseconds")}

but it shows Modifier 'override' is not applicable in local function

Answer 1

Create interface in ProximityDetector.kt file.

interface OnSensorValueChange{
    fun onValueChange(value: Long);
}

Implement it in SettingsActivity.kt file.

override fun onValueChange(value: Long) {
    timeTaken.setText("That took " + value + " milliseconds")
}

Pass the SettingsActivity reference in ProximityDetector class constructor and assign it.

class ProximityDetector constructor(var onSensorValueChange: ProximityDetector.OnSensorValueChange)

and call method of interface to update value.

    override fun onSensorChanged(event: SensorEvent) {
       val distance = event.values[0]
       val max = event.sensor.maximumRange
       a = System.currentTimeMillis()
    if (distance < Math.min(max, 8.toFloat())) {
        listener.onNear()
    } else {
        listener.onFar()
    }

        b = System.currentTimeMillis()
    System.out.println("That took " + (b- a) + " milliseconds")
    onSensorValueChange.onValueChange((b- a)) //add this line.
}  

Answer 2

In kotlin don't use getters and setters as like in java.The correct format of the kotlin is given below.

val textView: TextView = findViewById(R.id.android_text) as TextView
textView.setOnClickListener {
    textView.text = getString(R.string.name)
}

To get the values from the Textview we have to use this method

val str: String = textView.text.toString()

 println("the value is $str")