Action whenever the text is changed in the EditText View.
Application to implement a listener
TextWatcher object, for EditText to trigger an action on text change.
Create a new Project in Kotlin
Message can display outside of our application normal UI
1 Open Android Studio.
2 Go to File => New => New Project. Write application name . Then, check Include Kotlin Support and click next button.
3Select minimum SDK you need. However, we have selected 17 as minimum SDK. Then, click next button
4 Then, select Empty Activity => click next => click finish.
5 You will get a newly created project successfully if you have followed steps properly.
Use the below code to Implement a Edittext with Kotlin
MainActivity.kt
import android.support.v7.app.AppCompatActivity
import android.os.Bundle
import android.text.Editable
import android.text.TextWatcher
import kotlinx.android.synthetic.main.activity_main.*
class MainActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
editTextSample.addTextChangedListener(object : TextWatcher {
override fun afterTextChanged(s: Editable) {}
override fun beforeTextChanged(s: CharSequence, start: Int,
count: Int, after: Int) {
}
override fun onTextChanged(s: CharSequence, start: Int,
before: Int, count: Int) {
tvSample.setText("Text is : "+s)
}
})
}
}
main_activity.xml
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<LinearLayout
android:layout_marginTop="20dp"
android:orientation="vertical"
android:padding="10sp"
android:gravity="center_horizontal"
android:layout_width="match_parent"
android:layout_height="match_parent">
android:layout_height="wrap_content" />
<EditText
android:id="@+id/editTextSample"
android:textSize="20sp"
android:layout_marginTop="50dp"
android:hint="Enter Text ..."
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
<TextView
android:id="@+id/tvSample"
android:layout_marginTop="20dp"
android:textColor="@color/colorPrimary"
android:textStyle="bold"
android:textSize="16dp"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
</LinearLayout>
</android.support.constraint.ConstraintLayout>
Output
