Android Checkbox Tutorial

View more Tutorials:

1- Android CheckBox

In Android, CheckBox is a button with two states,  checked and unchecked. It is a basic component and frequently used in Android applications.
Basically, you can use multiple CheckBoxes in the application to allow users to select one or more options in a set of values.
By default, the CheckBoxes have the  unchecked state, so you can change its state via the  android:checked attribute.
<CheckBox
    android:id="@+id/someId"
    android:checked="true"
    ... />
Some important attributes of CheckBox:
Attribute Description
android:checked Specify the current status for the CheckBox.
android:gravity Align the text of the CheckBox. The possible values are left, right, center, top, ...
android:text Set text content for CheckBox.
android:textColor Set the color of the text.
android:textSize Set font size of text.
android:textStyle Set text style (bold, italic, bolditalic).
android:background Set the background color for the CheckBox.
android:padding Set padding for CheckBox.
android:onClick The name of the method will be called when the user clicks on CheckBox.
There are quite a few events related to a CheckBox, but here are two events used most often:
  • checkBox.setOnClickListener(View.OnClickListener)
  • checkBox.setOnCheckedChangeListener(CompoundButton.OnCheckedChangeListener)

On Click Event:

The event occurs when the user clicks on the CheckBox, similarly when the user clicks on a Button.
CheckBox chk = (CheckBox) findViewById(R.id.chk1);

chk.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        boolean checked = ((CheckBox) v).isChecked();
        // Check which checkbox was clicked
        if (checked){
            // Your coding   
        }
        else{
            // Your coding   
        }
    }
});

On Checked Change Event:

The event occurs when the CheckBox changes its state, due to the user's action or the effect of calling the  checkBox.setChecked(newState) method.
CheckBox chk = (CheckBox) findViewById(R.id.chk1);

chk.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
    @Override
    public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
        if(isChecked)  {
           // Your code
        } else {
           // Your code
        }
    }
});

2- An example of the CheckBox

Now let's take a quick look before we start:
The interface of the example application will look like this:
Note: If you are interested in the steps to design the interface of this application, please check out the appendix at the end of the article.
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <TextView
        android:id="@+id/textView"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="16dp"
        android:layout_marginLeft="16dp"
        android:layout_marginTop="35dp"
        android:layout_marginEnd="16dp"
        android:layout_marginRight="16dp"
        android:text="What programming languages do you like?"
        android:textSize="18sp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <CheckBox
        android:id="@+id/checkBox_checkAll"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="16dp"
        android:layout_marginLeft="16dp"
        android:layout_marginTop="39dp"
        android:layout_marginEnd="16dp"
        android:layout_marginRight="16dp"
        android:text="(Check All)"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/textView" />

    <CheckBox
        android:id="@+id/checkBox_ccpp"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="16dp"
        android:layout_marginLeft="16dp"
        android:layout_marginTop="16dp"
        android:layout_marginEnd="16dp"
        android:layout_marginRight="16dp"
        android:text="C/C++"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/checkBox_checkAll" />

    <CheckBox
        android:id="@+id/checkBox_csharp"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="16dp"
        android:layout_marginLeft="16dp"
        android:layout_marginTop="16dp"
        android:layout_marginEnd="16dp"
        android:layout_marginRight="16dp"
        android:text="CSharp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/checkBox_ccpp" />

    <CheckBox
        android:id="@+id/checkBox_java"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="16dp"
        android:layout_marginLeft="16dp"
        android:layout_marginTop="16dp"
        android:layout_marginEnd="16dp"
        android:layout_marginRight="16dp"
        android:text="Java"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/checkBox_csharp" />

    <Button
        android:id="@+id/button_showResult"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="16dp"
        android:text="Show Result"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/checkBox_java" />
</androidx.constraintlayout.widget.ConstraintLayout>
MainActivity.java
package com.example.checkboxexample;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.CompoundButton;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

    private CheckBox checkBoxCheckAll;
    private CheckBox checkBoxCcpp;
    private CheckBox checkBoxCsharp;
    private CheckBox checkBoxJava;

    private Button buttonShowResult;

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

        this.checkBoxCheckAll = (CheckBox) this.findViewById(R.id.checkBox_checkAll);
        this.checkBoxCcpp = (CheckBox) this.findViewById(R.id.checkBox_ccpp);
        this.checkBoxCsharp = (CheckBox) this.findViewById(R.id.checkBox_csharp);
        this.checkBoxJava = (CheckBox) this.findViewById(R.id.checkBox_java);

        this.buttonShowResult = (Button) this.findViewById(R.id.button_showResult);

        this.buttonShowResult.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                showResult();
            }
        });

        this.checkBoxCheckAll.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                checkAllCheckedChange(isChecked);
            }
        });
    }

    private void showResult()  {
        String message = null;
        if(this.checkBoxCcpp.isChecked()) {
            message =  this.checkBoxCcpp.getText().toString();
        }
        if(this.checkBoxCsharp.isChecked()) {
            if(message== null)  {
                message =  this.checkBoxCsharp.getText().toString();
            } else {
                message += ", " + this.checkBoxCsharp.getText().toString();
            }
        }
        if(this.checkBoxJava.isChecked()) {
            if(message== null)  {
                message =  this.checkBoxJava.getText().toString();
            } else {
                message += ", " + this.checkBoxJava.getText().toString();
            }
        }
        message = message == null? "You select nothing": "You select: " + message;
        Toast.makeText(this, message, Toast.LENGTH_LONG).show();
    }

    // When "Check All" change state.
    private void checkAllCheckedChange(boolean isChecked)  {
        this.checkBoxCsharp.setChecked(isChecked);
        this.checkBoxCcpp.setChecked(isChecked);
        this.checkBoxJava.setChecked(isChecked);
    }
}

3- Appendix: Interface design

Here are some steps to design the application interface (of the above example).
Set ID, Text for the component in the interface:
  • textView: textSize="18sp"

View more Tutorials: