Android Blog - Simple Radio Button

A Radio button is similar to check boxes where in it has two states checked or unchecked.  So what is the difference between a radio button and a checkbox, well it’s simple in case of checkbox user can uncheck it which is not possible in case of radio buttons. Hence when you use radio buttons use it in Radio Groups where in at any time only one option can be selected.

                In this post I have created 2 radio buttons called ‘India’ and ‘New Zealand’, a Button called ‘Done’. Once a user clicks on the ’Done’ button it should show ‘You Selected -<Country Name>’.

Create a project and add the following –

Main.xml - Open the main.xml file in layout folder. Remove the default textview. Add a Large Text and add the app name to this. Then drag a medium text and have a label ‘Select Country’. Then add 2 radio buttons and call them India and New Zealand. Add a button and label it ‘Done’. On clicking the button you need to display the country which has been selected, so include a text view in it which you will set using java code.

The layout should like the one below –

RadioButton_Activity.Java – Open the class file RadioButton_Activity.Java in src folder. Here you need to declare and bind the Radio Button which you have created in the Main.xml file. Hence you need to add code

R1=(RadioButton) findViewById(R.id.radioButton1);       

R2=(RadioButton) findViewById(R.id.radioButton2);

Then you need to add a button called ‘Done’ and a listener which will set the text to ‘You Selected -<Country Name>’ as shown in the  code below

Done=(Button) findViewById(R.id.button1);

        tv=(TextView) findViewById(R.id.textView3);

        Done.setOnClickListener(new View.OnClickListener() {

                                               

                                                @Override

                                                public void onClick(View V) {

                                                                if(R1.isChecked()){

                                                                                tv.setText("You Selected - "+R1.getText());

                                                                }

                                                                if(R2.isChecked()){

                                                                                tv.setText("You Selected - "+R2.getText());

                                                                }

                                                }

                                });

The code will finally look like the one below 

And, we are done with coding, simple wasn’t it. Now lets see if it works, right click on the project and click on run as android application. The initial screen which you get will be as shown in the below

Now click on a country and click on the Done button, in this case I have clicked on India and the result is as shown below.

Well that was easy, I will tell how to use radio groups in my next post.