RadioButton in Android

 

Android RadioButton

RadioButton is a two states button which is either checked or unchecked. If a single radio button is unchecked, we can click it to make checked radio button. Once a radio button is checked, it cannot be marked as unchecked by user.

RadioButton is generally used with RadioGroup. RadioGroup contains several radio buttons, marking one radio button as checked makes all other radio buttons as unchecked.

Example of Radio Button

In this example, we are going to implement single radio button separately as well as radio button in RadioGroup.

activity_main.xml

File: activity_main.xml

1. <?xml version="1.0" encoding="utf-8"?>  
2. <LinearLayout  
3.     xmlns:android="http://schemas.android.com/apk/res/android"  
4.     xmlns:tools="http://schemas.android.com/tools"  
5.     android:layout_width="match_parent"  
6.     android:layout_height="match_parent"  
7.     android:orientation="vertical"  
8.     tools:context="example.javatpoint.com.radiobutton.MainActivity">  
9.   
10.     <TextView  
11.         android:id="@+id/textView1"  
12.         android:layout_width="fill_parent"  
13.         android:layout_height="wrap_content"  
14.         android:layout_marginTop="30dp"  
15.         android:gravity="center_horizontal"  
16.         android:textSize="22dp"  
17.         android:text="Single Radio Buttons" />  
18.   
19.   
20.   
21.     <!--   Default RadioButtons  -->  
22.   
23.     <RadioButton  
24.         android:id="@+id/radioButton1"  
25.         android:layout_width="fill_parent"  
26.         android:layout_height="wrap_content"  
27.         android:layout_gravity="center_horizontal"  
28.         android:text="Radio Button 1"  
29.         android:layout_marginTop="20dp"  
30.   
31.         android:textSize="20dp" />  
32.     <RadioButton  
33.         android:id="@+id/radioButton2"  
34.         android:layout_width="fill_parent"  
35.         android:layout_height="wrap_content"  
36.         android:text="Radio Button 2"  
37.         android:layout_marginTop="10dp"  
38.   
39.         android:textSize="20dp" />  
40.   
41.   
42.     <View  
43.         android:layout_width="fill_parent"  
44.         android:layout_height="1dp"  
45.         android:layout_marginTop="20dp"  
46.         android:background="#B8B894" />  
47.   
48.     <TextView  
49.         android:id="@+id/textView2"  
50.         android:layout_width="fill_parent"  
51.         android:layout_height="wrap_content"  
52.         android:layout_marginTop="30dp"  
53.         android:gravity="center_horizontal"  
54.         android:textSize="22dp"  
55.         android:text="Radio button inside RadioGroup" />  
56.   
57.   
58.     <!--   Customized RadioButtons  -->  
59.   
60.   
61.     <RadioGroup  
62.         android:layout_width="wrap_content"  
63.         android:layout_height="wrap_content"  
64.         android:id="@+id/radioGroup">  
65.   
66.         <RadioButton  
67.             android:id="@+id/radioMale"  
68.             android:layout_width="fill_parent"  
69.             android:layout_height="wrap_content"  
70.             android:text="  Male"  
71.             android:layout_marginTop="10dp"  
72.             android:checked="false"  
73.             android:textSize="20dp" />  
74.   
75.         <RadioButton  
76.             android:id="@+id/radioFemale"  
77.             android:layout_width="fill_parent"  
78.             android:layout_height="wrap_content"  
79.             android:text="   Female"  
80.             android:layout_marginTop="20dp"  
81.             android:checked="false"  
82.   
83.             android:textSize="20dp" />  
84.     </RadioGroup>  
85.   
86.     <Button  
87.         android:layout_width="wrap_content"  
88.         android:layout_height="wrap_content"  
89.         android:text="Show Selected"  
90.         android:id="@+id/button"  
91.         android:onClick="onclickbuttonMethod"  
92.         android:layout_gravity="center_horizontal" />  
93.   
94.   
95. </LinearLayout>  
96. File: MainActivity.java
97. package example.javatpoint.com.radiobutton;  
98.   
99. import android.support.v7.app.AppCompatActivity;  
100. import android.os.Bundle;  
101. import android.view.View;  
102. import android.widget.Button;  
103. import android.widget.RadioButton;  
104. import android.widget.RadioGroup;  
105. import android.widget.Toast;  
106.   
107. public class MainActivity extends AppCompatActivity {  
108.     Button button;  
109.     RadioButton genderradioButton;  
110.     RadioGroup radioGroup;  
111.     @Override  
112.     protected void onCreate(Bundle savedInstanceState) {  
113.         super.onCreate(savedInstanceState);  
114.         setContentView(R.layout.activity_main);  
115.         radioGroup=(RadioGroup)findViewById(R.id.radioGroup);  
116.     }  
117.     public void onclickbuttonMethod(View v){  
118.         int selectedId = radioGroup.getCheckedRadioButtonId();  
119.         genderradioButton = (RadioButton) findViewById(selectedId);  
120.         if(selectedId==-1){  
121.             Toast.makeText(MainActivity.this,"Nothing selected", Toast.LENGTH_SHORT).show();  
122.         }  
123.         else{  
124.             Toast.makeText(MainActivity.this,genderradioButton.getText(), Toast.LENGTH_SHORT).show();  
125.         }  
126.   
127.     }  
128. }