{"id":914,"date":"2016-02-15T06:30:27","date_gmt":"2016-02-15T06:30:27","guid":{"rendered":"http:\/\/abhiandroid.com\/ui\/?page_id=914"},"modified":"2019-06-12T10:08:24","modified_gmt":"2019-06-12T10:08:24","slug":"radiobutton","status":"publish","type":"page","link":"https:\/\/abhiandroid.com\/ui\/radiobutton","title":{"rendered":"RadioButton & RadioGroup Tutorial With Example In Android Studio"},"content":{"rendered":"

In Android, RadioButton are mainly used together in a RadioGroup. In RadioGroup checking the one radio button out of several radio button added\u00a0in it will automatically unchecked all the others. It means at one\u00a0time we can checked only one radio button from a group of radio buttons which belong to\u00a0same radio group. The most common use of radio button is in Quiz Android App code<\/a>.<\/p>\n

\"RadioButton\"<\/center>RadioButon is a two state button that can be checked or unchecked. If a radio button is unchecked then a user can check it by simply clicking on it. Once a RadiaButton is checked by user it can\u2019t be unchecked by simply pressing on the same button. It will automatically unchecked when you press any other RadioButton within same RadioGroup.<\/p>\n

Important\u00a0Note: <\/strong><\/span>RadioGroup is a widget used in Android for the grouping of radio buttons and provide the feature\u00a0of selecting only one radio button from the set.\u00a0When a user try to select any other radio button within same radio group the previously selected radio button will be automatically unchecked.<\/p>\n

RadioGroup And RadioButton code in XML:<\/strong><\/p>\n

<RadioGroup\r\n    android:layout_width=\"wrap_content\"\r\n    android:layout_height=\"wrap_content\">\r\n        <RadioButton\r\n        android:id=\"@+id\/simpleRadioButton\"\r\n        android:layout_width=\"wrap_content\"\r\n        android:layout_height=\"wrap_content\"\/>\r\n        <RadioButton\r\n        android:id=\"@+id\/simpleRadioButton1\"\r\n        android:layout_width=\"wrap_content\"\r\n        android:layout_height=\"wrap_content\"\/>\r\n<\/RadioGroup><\/pre>\n
\"RadioButton<\/center>Checking Current State Of Radio Button:<\/strong><\/span><\/p>\n
You can check the current state of a radio button programmatically by using isChecked() method. This method returns a Boolean value either\u00a0true or false. if it\u00a0is checked then returns true otherwise returns false. Below is an example code with explanation in which we checked the current state of a radio button.<\/p>\n
\/*Add in Oncreate() funtion after setContentView()*\/\r\nRadioButton simpleRadioButton = (RadioButton) findViewById(R.id.simpleRadioButton<\/em><\/strong>); \/\/ initiate a radio button\r\n\r\nBoolean RadioButtonState = simpleRadioButton.isChecked(); \/\/ check current state of a radio button (true or false).\r\n<\/pre>\n
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 <\/p>\n
Attributes of RadioButton In Android:<\/strong><\/h4>\n
Now let\u2019s \u00a0we discuss important\u00a0attributes that helps us to create\u00a0a beautiful radio button in xml file (layout).<\/p>\n
1. id:<\/span>\u00a0<\/strong>id is an attribute used to uniquely identify a radio button.<\/p>\n
<RadioButton\r\n    android:id=\"@+id\/simpleRadioButton\"\r\n    android:layout_width=\"wrap_content\"\r\n    android:layout_height=\"wrap_content\"\/><\/pre>\n
2. checked:<\/span>\u00a0<\/strong>checked attribute in radio button is used to set the current state of a radio button. We can set it either true or false\u00a0where true shows the checked state and false shows unchecked state of a radio button. As usual\u00a0default value of checked attribute is false. We can also set the current state in JAVA.<\/p>\n
Below we set true value for checked attribute which\u00a0sets the current state to checked of a Button<\/p>\n
<RadioButton\r\n    android:id=\"@+id\/simpleRadioButton\"\r\n    android:layout_width=\"wrap_content\" \r\n    android:layout_height=\"wrap_content\"\r\n    android:checked=\"true\"\/> <!-- set the current state of the radio button--><\/pre>\n
\"Checked<\/center>Setting checked State Of RadioButton In Java Class:<\/strong><\/p>\n
Below code set the current state of RadioButton to checked programmatically.<\/p>\n
\/*Add in Oncreate() funtion after setContentView()*\/\r\n\/\/ initiate a radio button\r\nRadioButton simpleRadioButton = (RadioButton) findViewById(R.id.simpleRadioButton<\/em><\/strong>);\r\n\r\n\/\/ set the current state of a radio button\r\nsimpleRadioButton.setChecked(true<\/strong>);<\/pre>\n
3. text:<\/strong><\/span> text attribute is used to set the text in a radio button. We can set the text both ways either in XML\u00a0or in\u00a0JAVA\u00a0class.<\/p>\n
Below is the example code with explanation included in which we set the text \u201cI am a radiobutton\u201d of a\u00a0 radio button.<\/p>\n
<RadioButton\r\n    android:id=\"@+id\/simpleRadioButton\"\r\n    android:layout_width=\"wrap_content\"\r\n    android:layout_height=\"wrap_content\"\r\n    android:checked=\"true\"\r\n    android:layout_centerHorizontal=\"true\"\r\n    android:text=\"I am a radiobutton\" \/> <!-- displayed text of radio button--><\/pre>\n
Setting text of RadioButton In Java class:<\/strong><\/p>\n
Below we set the text of a radio button programmatically:<\/p>\n
\/*Add in Oncreate() funtion after setContentView()*\/\r\nRadioButton simpleRadioButton=(RadioButton) findViewById(R.id.simpleRadioButton);\r\nsimpleRadioButton.setText(\"I am a radiobutton\"); \/\/ displayed text of radio button<\/pre>\n
\"text<\/center>4. gravity:<\/span>\u00a0<\/strong>The gravity attribute is an optional attribute which is used to control the alignment of text like left, right, center, top, bottom, center_vertical, center_horizontal etc.<\/p>\n
Below is the example code with explanation included in which we set the center gravity for the text of a radio button.<\/p>\n
<RadioButton\r\n    android:id=\"@+id\/simpleRadioButton\"\r\n    android:layout_width=\"fill_parent\"\r\n    android:layout_height=\"wrap_content\"\r\n    android:checked=\"true\"\r\n    android:text=\"I am a Button\"\r\n    android:gravity=\"center\"\/> <!-- center gravity of the text--><\/pre>\n
\"gravity<\/center>5. textColor:<\/strong><\/span>\u00a0textColor attribute is used to set the text color of a radio button. Color value is in the form of “#argb”, “#rgb”, “#rrggbb”, or “#aarrggbb”.<\/p>\n
Below we set the red color for the displayed text of a radio button.<\/p>\n
<RadioButton\r\n    android:id=\"@+id\/simpleRadioButton\"\r\n    android:layout_width=\"wrap_content\"\r\n    android:layout_height=\"wrap_content\"\r\n    android:checked=\"true\"\r\n    android:layout_centerHorizontal=\"true\"\r\n    android:text=\"Male\"\r\n    android:textColor=\"#f00\" \/><!--red color for displayed text--><\/pre>\n
\u00a0\"textColor<\/center>Setting textColor of RadioButton text In Java class:<\/strong><\/p>\n
Below we set the text color of a radio button programmatically.<\/p>\n
\/*Add in Oncreate() funtion after setContentView()*\/\r\nRadioButton simpleRadioButton = (RadioButton) findViewById(R.id.simpleRadioButton<\/em><\/strong>);\/\/ initiate radio button\r\n\r\nsimpleRadioButton.setTextColor(Color.RED<\/em><\/strong>); \/\/red color for displayed text of radio button<\/pre>\n
6. textSize:<\/strong><\/span>\u00a0textSize attribute is used to set the size of the text of a radio button. We can set the text size in sp(scale independent pixel) or dp(density pixel).<\/p>\n
Below we set the 25sp size for the text of a radio button.<\/p>\n
<RadioButton\r\n    android:id=\"@+id\/simpleRadioButton\"\r\n    android:layout_width=\"wrap_content\"\r\n    android:layout_height=\"wrap_content\"\r\n    android:checked=\"true\"\r\n    android:layout_centerHorizontal=\"true\"\r\n    android:text=\"AbhiAndroid\"\r\n    android:textColor=\"#f00\"\r\n    android:textSize=\"25sp\"\/> <!--setting  text size--><\/pre>\n
\"textsize<\/center>Setting textSize Of RadioButton Text In Java class:<\/strong><\/p>\n
Below we set the text size of a radio button programmatically:<\/p>\n
\/*Add in Oncreate() funtion after setContentView()*\/\r\nRadioButton simpleRadioButton = (RadioButton) findViewById(R.id.simpleRadioButton<\/em><\/strong>); \/\/ initiate radio button\r\n\r\nsimpleRadioButton.setTextSize(25); \/\/ set 25sp displayed text size of radio button<\/pre>\n
7. textStyle:<\/strong><\/span>\u00a0textStyle attribute is used to set the text style of the text of a radio button. The possible text styles are bold, italic and normal. If we need to use two or more styles for a text view then \u201c|\u201d operator is used for that.<\/p>\n
Below is the example code with explanation included in which we set the bold and italic text styles for text of a radio button.<\/p>\n
<RadioButton\r\n    android:id=\"@+id\/simpleRadioButton\"\r\n    android:layout_width=\"wrap_content\"\r\n    android:layout_height=\"wrap_content\"\r\n    android:checked=\"true\"\r\n    android:textSize=\"25sp\"\r\n    android:layout_centerHorizontal=\"true\"\r\n    android:text=\"Male\"\r\n    android:textColor=\"#f00\"\r\n    android:textStyle=\"bold|italic\"\/> <!-- bold and italic text style--><\/pre>\n
\"textStyle<\/center>8. background:<\/strong><\/span>\u00a0background attribute is used to set the background of a radio button. We can set a color or a drawable in the background of a radio button.<\/p>\n
Below we set the black color for the background and red color for the displayed text of a radio button.<\/p>\n
<RadioButton\r\n    android:id=\"@+id\/simpleRadioButton\"\r\n    android:layout_width=\"wrap_content\"\r\n    android:layout_height=\"wrap_content\"\r\n    android:checked=\"true\"\r\n    android:textSize=\"25sp\"\r\n    android:textStyle=\"bold|italic\"\r\n    android:padding=\"20dp\"\r\n    android:layout_centerHorizontal=\"true\"\r\n    android:text=\"Male\"\r\n    android:textColor=\"#f00\"\r\n    android:background=\"#000\"\/> <!-- black background for radio button--><\/pre>\n
\"background<\/center>Setting Background Of RadioButton In Java class:<\/strong><\/p>\n
Below we set the background color of a radio button programmatically.<\/p>\n
\/*Add in Oncreate() funtion after setContentView()*\/\r\nRadioButton simpleRadioButton = (RadioButton) findViewById(R.id.simpleRadioButton<\/em><\/strong>);\r\n\r\nsimpleRadioButton.setBackgroundColor(Color.BLACK<\/em><\/strong>);<\/pre>\n
9. padding:<\/strong><\/span> padding attribute is used to set the padding from left, right, top or bottom.<\/p>\n