Android switch button example

A switch is type of button that can only have two states ON and OFF. You can set the initial state and then the user can change it. To get the current state you can check if the switch is checked or not, in addition to that you can attach a OnCheckedChangeListener to the switch to get notification when the state changes.

Android Screen Layout

<RelativeLayout 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" 
    android:padding="5dp">

    <Switch
        android:id="@+id/mySwitch"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:layout_marginTop="20dp"
        android:text="Play with the Switch" />

    <TextView
        android:id="@+id/switchStatus"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_below="@+id/mySwitch"
        android:layout_marginTop="22dp"
        android:text="Medium Text"
        android:textAppearance="?android:attr/textAppearanceMedium" />
    
</RelativeLayout>

Android Main Activity

package com.as400samplecode;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.widget.CompoundButton;
import android.widget.CompoundButton.OnCheckedChangeListener;
import android.widget.Switch;
import android.widget.TextView;

public class MainActivity extends Activity {

 private TextView switchStatus;
 private Switch mySwitch;

 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);

  switchStatus = (TextView) findViewById(R.id.switchStatus);
  mySwitch = (Switch) findViewById(R.id.mySwitch);

  //set the switch to ON 
  mySwitch.setChecked(true);
  //attach a listener to check for changes in state
  mySwitch.setOnCheckedChangeListener(new OnCheckedChangeListener() {

   @Override
   public void onCheckedChanged(CompoundButton buttonView,
     boolean isChecked) {

    if(isChecked){
     switchStatus.setText("Switch is currently ON");
    }else{
     switchStatus.setText("Switch is currently OFF");
    }

   }
  });
  
  //check the current state before we display the screen
  if(mySwitch.isChecked()){
   switchStatus.setText("Switch is currently ON");
  }
  else {
   switchStatus.setText("Switch is currently OFF");
  }
 }

 @Override
 public boolean onCreateOptionsMenu(Menu menu) {
  // Inflate the menu; this adds items to the action bar if it is present.
  getMenuInflater().inflate(R.menu.activity_main, menu);
  return true;
 }

}

Reference

• Android Switch API Reference