Android CheckBox with Examples

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  Keywords : Android checkbox control is a two states button that can be either checked or unchecked, Android checkbox control is like on / off switch and that will toggle between the either on or off

Here we will learn checkboxes in android with examples and how to use multiple android checkboxes to select one or more options and get selected checkbox control values with examples.

Android CheckBox UI Control

In android, CheckBox is a two states button that can be either checked (ON) or unchecked (OFF) and it will allow users to toggle between the two states (ON / OFF) based on the requirements.

 

Generally, we can use multiple CheckBox controls in android application to allow users to select one or more options from the set of values.

 

Following is the pictorial representation of using CheckBox control in android applications.

 

Android CheckBoxes Example Diagram

 

By default, the android CheckBox will be in OFF (Unchecked) state. We can change the default state of CheckBox by using android:checked attribute.

 

In case, if we want to change the state of CheckBox to ON (Checked), then we need to set android:checked = “true” in our XML layout file.

 

In android, we can create CheckBox control in two ways either in XML layout file or create it in Activity file programmatically.

Create CheckBox in XML Layout File

Following is the sample way to define CheckBox control in XML layout file in android application.

 

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
   
android:layout_width="match_parent" android:layout_height="match_parent">
<
CheckBox
   
android:id="@+id/chk1"
   
android:layout_width="wrap_content"
   
android:layout_height="wrap_content"
   
android:checked="true"
   
android:text="Java" /> </RelativeLayout>

If you observe above code snippet, here we defined CheckBox control and setting CheckBox state ON using android:checked attribute in xml layout file.

Create CheckBox Control in Activity File

In android, we can create CheckBox control programmatically in activity file based on our requirements. 

 

Following is the example of creating a CheckBox control dynamically in activity file.

 

LinearLayout layout = (LinearLayout)findViewById(R.id.l_layout);
CheckBox cb =
new CheckBox(this);
cb.setText(
"Tutlane");
cb.setChecked(
true);
layout.addView(cb);

This is how we can define CheckBox in XML layout file or programmatically in activity file based on our requirements.

Handle Android CheckBox Click Events

Generally, whenever the user click on CheckBox to Select or Deselect the CheckBox object will receives an on-click event.

 

In android, we can define CheckBox click event in two ways either in XML layout file or create it in Activity file programmatically.

Define CheckBox Click Event in XML Layout File

We can define click event handler for button by adding android:onClick attribute to the <CheckBox> element in our XML layout file.

 

The value of android:onClick attribute must be the name of method which we need to call in response to a click event and the Activity file which hosting XML layout must implement the corresponding method.

 

Following is the example of defining a CheckBox click event using android:onClick attribute in XML layout file.

 

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
   
android:orientation="vertical" android:layout_width="match_parent"
   
android:layout_height="match_parent">
    <
CheckBox
    
android:id="@+id/chk1"
   
android:layout_width="wrap_content"
   
android:layout_height="wrap_content"
   
android:checked="true"
   
android:text="Java"

    android:onClick="onCheckBoxClick"/>
</
LinearLayout>

In Activity that hosts our XML layout file, we need to implement click event method like as shown below.

 

public void onCheckboxClicked(View view) {
   
// Is the view now checked?
   
boolean checked = ((CheckBox) view).isChecked();
   
// Check which checkbox was clicked
   
switch(view.getId()) {
       
case R.id.chk1:
           
if (checked)
           
// Do your coding
       
else
           
// Do your coding

            break;
       
// Perform your logic
    }
}

Define CheckBox Click Event in Activity File

In android, we can define CheckBox click event programmatically in Activity file rather than XML layout file.

 

To define checkbox click event programmatically, create View.OnClickListener object and assign it to the button by calling setOnClickListener(View.OnClickListener) like as shown below.

 

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){
           
// Do your coding   
       
}
       
else{
           
// Do your coding   
       
}
    }
});

This is how we can handle CheckBox click events in android applications based on our requirements.

Android CheckBox Control Attributes

Following are the some of commonly used attributes related to CheckBox control in android applications.

 

AttributeDescription
android:id It is used to uniquely identify the control
android:checked It is used to specify the current state of checkbox
android:gravity It is used to specify how to align the text like left, right, center, top, etc.
android:text It is used to set the text for checkbox.
android:textColor It is used to change the color of text.
android:textSize It is used to specify the size of text.
android:textStyle It is used to change the style (bold, italic, bolditalic) of text.
android:background It is used to set the background color for checkbox control.
android:padding It is used to set the padding from left, right, top and bottom.
android:onClick It’s a name of the method to invoke when the checkbox clicked.
android:visibility It is used to control the visibility of control.

Android CheckBox Control Example

Following is the example of defining a multiple CheckBox controls and one Button control in LinearLayout to get the selected values of CheckBox controls when we click on Button in android application.

 

Create a new android application using android studio and give names as CheckBoxExample. In case if you are not aware of creating an app in android studio check this article Android Hello World App.

 

Now open an activity_main.xml file from \res\layout path and write the code like as shown below

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    
android:orientation="vertical" android:layout_width="match_parent"
   
android:layout_height="match_parent">
    <
CheckBox
       
android:id="@+id/chkJava"
       
android:layout_width="wrap_content"
       
android:layout_height="wrap_content"
       
android:padding="10dp"
       
android:layout_marginTop="150dp"
       
android:layout_marginLeft="100dp"
       
android:text="Java"
       
android:onClick="onCheckboxClicked"/>
    <
CheckBox
       
android:id="@+id/chkPython"
       
android:layout_width="wrap_content"
       
android:layout_height="wrap_content"
       
android:padding="10dp"
       
android:layout_marginLeft="100dp"
       
android:text="Python"
       
android:onClick="onCheckboxClicked"/>
    <
CheckBox
       
android:id="@+id/chkAndroid"
       
android:layout_width="wrap_content"
       
android:layout_height="wrap_content"
       
android:padding="10dp"
       
android:layout_marginLeft="100dp"
       
android:text="Android"
       
android:onClick="onCheckboxClicked"/>
    <
CheckBox
       
android:id="@+id/chkAngular"
       
android:layout_width="wrap_content"
       
android:layout_height="wrap_content"
       
android:padding="10dp"
       
android:layout_marginLeft="100dp"
       
android:text="AngularJS"
       
android:onClick="onCheckboxClicked"/>
    <
Button
       
android:id="@+id/getBtn"
       
android:layout_width="wrap_content"
       
android:layout_height="wrap_content"
       
android:layout_marginLeft="100dp"
       
android:text="Get Details" />
</
LinearLayout>

If you observe above code we created a multiple CheckBox controls and one Button control in XML Layout file. 

 

Once we are done with creation of layout with required controls, we need to load the XML layout resource from our activity onCreate() callback method, for that open main activity file MainActivity.java from \java\com.tutlane.checkboxexample path and write the code like as shown below.

MainActivity.java

package com.tutlane.checkboxexample;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {
    CheckBox
android, java, angular, python;
   
@Override
   
protected void onCreate(Bundle savedInstanceState) {
       
super.onCreate(savedInstanceState);
        setContentView(R.layout.
activity_main);
       
android = (CheckBox)findViewById(R.id.chkAndroid);
       
angular = (CheckBox)findViewById(R.id.chkAngular);
       
java = (CheckBox)findViewById(R.id.chkJava);
       
python = (CheckBox)findViewById(R.id.chkPython);
        Button btn = (Button)findViewById(R.id.
getBtn);
        btn.setOnClickListener(
new View.OnClickListener() {
           
@Override
            
public void onClick(View v) {
                String result =
"Selected Courses";
               
if(android.isChecked()){
                result +=
"\nAndroid";
                }
               
if(angular.isChecked()){
                    result +=
"\nAngularJS";
                }
               
if(java.isChecked()){
                    result +=
"\nJava";
                }
               
if(python.isChecked()){
                    result +=
"\nPython";
                }
                Toast.makeText(getApplicationContext(), result, Toast.
LENGTH_SHORT).show();
            }
        });
    }
   
public void onCheckboxClicked(View view) {
       
boolean checked = ((CheckBox) view).isChecked();
        String str=
"";
       
// Check which checkbox was clicked
       
switch(view.getId()) {
           
case R.id.chkAndroid:
                str = checked?
"Android Selected":"Android Deselected";
               
break;
           
case R.id.chkAngular:
                str = checked?
"AngularJS Selected":"AngularJS Deselected";
               
break;
           
case R.id.chkJava:
                str = checked?
"Java Selected":"Java Deselected";
               
break;
           
case R.id.chkPython:
                str = checked?
"Python Selected":"Python Deselected";
               
break;
        }
        Toast.makeText(getApplicationContext(), str, Toast.
LENGTH_SHORT).show();
    }
}

If you observe above code we are calling our layout using setContentView method in the form of R.layout.layout_file_name in our activity file. Here our xml file name is activity_main.xml so we used file name activity_main and we are getting the status of CheckBox controls when they Select / Deselect and getting the selected CheckBox control values on Button click.

 

Generally, during the launch of our activity, onCreate() callback method will be called by android framework to get the required layout for an activity.

Output of Android CheckBox Example

When we run above example using android virtual device (AVD) we will get a result like as shown below.

 

Android CheckBox Control Example Result

 

If you observe above result, we are able to get status of checkboxes while selecting / deselecting and getting all the selected CheckBox values on button click.

 

This is how we can use CheckBox control in android applications to allow users to select one or more options based on our requirements.

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