title: Custom icon for a radio button
body: <p>I am trying to implement a custom icon for the radio button in android. i.e. I want the Radio button icon to be custom one of my choice. I am able to do that with <code>android:button</code> property inside the radio button but I am not getting on how to define it when the user clicks it. In my application when the user clicks it nothing happens. I have also followed this guide <a href="https://stackoverflow.com/questions/3576507/is-it-possible-to-change-the-radio-button-icon-in-an-android-radio-button-group">here</a>.</p>
  
  <pre><code>I have 2 images :
   A. tire.png (When the radio button is not clicked)
   B. tireinvert.png (When the radio button is clicked)
  </code></pre>
  
  <p>My RadioButton.xml file :</p>
  
  <pre><code>&lt;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"
      android:paddingBottom="@dimen/activity_vertical_margin"
      android:paddingLeft="@dimen/activity_horizontal_margin"
      android:paddingRight="@dimen/activity_horizontal_margin"
      android:paddingTop="@dimen/activity_vertical_margin"
      tools:context="com.techfrk.customizeradiobutton.MainActivity" &gt;
  
      &lt;TextView
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:text="@string/hello_world" /&gt;
  
       &lt;RadioGroup
                  android:id="@+id/newexprgrp"
                  android:layout_width="wrap_content"
                  android:layout_height="wrap_content" &gt;
  
                  &lt;RadioButton
                  android:id="@+id/tvllocrbtn"
                  android:layout_width="match_parent"
                  android:layout_height="wrap_content"
                  android:layout_weight="1"
                  android:layout_marginLeft="20dp"
                  android:layout_marginTop="40dp"
                  android:text="Travelling Expense (Local)"
                  /&gt;
  
                    &lt;RadioButton
                  android:id="@+id/tvloutrbtn"
                  android:layout_width="match_parent"
                  android:layout_height="wrap_content"
                  android:layout_weight="1"
                  android:layout_marginLeft="20dp"
                  android:layout_marginTop="15dp"
                  android:text="Travelling Expense (Outstation)"
  
                   /&gt;
  
                 &lt;RadioButton
                  android:id="@+id/phnexprbtn"
                  android:layout_width="match_parent"
                  android:layout_height="wrap_content"
                  android:layout_weight="1"
                  android:layout_marginLeft="20dp"
                  android:layout_marginTop="15dp"
                  android:text="Phone Expense"
  
                   /&gt;
  
                     &lt;RadioButton
                  android:id="@+id/miscexprbtn"
                  android:layout_width="match_parent"
                  android:layout_height="wrap_content"
                  android:layout_weight="1"
                  android:layout_marginLeft="20dp"
                  android:layout_marginTop="15dp"
                  android:text="Misc Expense"
  
                   /&gt;
              &lt;/RadioGroup&gt;
  
  &lt;/RelativeLayout&gt;
  </code></pre>
  
  <p>Can anyone please guide me ?</p>