JRadioButton | Java Swing-yiteyi-C++库

我们使用JRadioButton类创建单选按钮。单选按钮用于从多个选项中选择一个选项。它用于填写表格、在线客观题和测验。

null

我们在按钮组中添加单选按钮，以便一次只能选择一个单选按钮。我们使用“ButtonGroup”类创建一个ButtonGroup，并在组中添加单选按钮。

使用的方法：

JRadioButton（）：创建一个没有文本的未选中单选按钮。例子：
```
JRadioButton j1 = new JRadioButton() 
```
JButton（String s）：创建带有特定文本的JButton。例子：
```
JButton b1 = new JButton("Button") 
```
JLabel（字符串s）：创建带有特定文本的JLabel。例子：
```
JLabel L = new JLabel("Label 1") 
```
ButtonGroup（）：用于创建一个组，我们可以在其中添加JRadioButton。在一个按钮组中，我们只能选择一个JRadioButton。 将单选按钮组合在一起的步骤。
- 使用“ButtonGroup（）”方法创建ButtonGroup实例。
```
ButtonGroup G = new ButtonGroup()
```
- 现在，在“add（）”方法的帮助下，在“G”组中添加按钮。
  例子：
```
G.add(Button1);
G.add(Button2);
```
isSelected（）：它将返回布尔值true或false，如果选择了JRadioButton，它将返回true，否则返回false。
例子：
```
JRadioButton.isSelected()
```
Set（…）和Get（…）方法： i） Set和get用于替换直接从外部类访问成员变量。
ii）不是直接访问类成员变量，而是定义get方法来访问这些变量，并设置方法来修改它们。

本链接中给出了程序中使用的一些功能的说明：功能描述

程序1：不带ActionListener的JRadioButton

                     // Java program to show JRadioButton Example.                   
                     // in java. Importing different Package.                   
                     import                               java.awt.*;                   
                     import                               javax.swing.*;                   
                     import                               java.awt.event.*;                   
                             
                     class                               Demo                               extends                               JFrame {                   
                             
                                         // Declaration of object of JRadioButton class.                   
                                         JRadioButton jRadioButton1;                   
                             
                                         // Declaration of object of JRadioButton class.                   
                                         JRadioButton jRadioButton2;                   
                             
                                         // Declaration of object of JButton class.                   
                                         JButton jButton;                   
                             
                                         // Declaration of object of ButtonGroup class.                   
                                         ButtonGroup G1;                   
                             
                                         // Declaration of object of  JLabel  class.                   
                                         JLabel L1;                   
                             
                                         // Constructor of Demo class.                   
                                         public                               Demo()                   
                                         {                   
                             
                                         // Setting layout as null of JFrame.                   
                                         this                               .setLayout(                               null                               );                   
                             
                                         // Initialization of object of "JRadioButton" class.                   
                                         jRadioButton1 =                               new                               JRadioButton();                   
                             
                                         // Initialization of object of "JRadioButton" class.                   
                                         jRadioButton2 =                               new                               JRadioButton();                   
                             
                                         // Initialization of object of "JButton" class.                   
                                         jButton =                               new                               JButton(                               "Click"                               );                   
                             
                                         // Initialization of object of "ButtonGroup" class.                   
                                         G1 =                               new                               ButtonGroup();                   
                             
                                         // Initialization of object of " JLabel" class.                   
                                         L1 =                               new                               JLabel(                               "Qualification"                               );                   
                             
                                         // setText(...) function is used to set text of radio button.                   
                                         // Setting text of "jRadioButton2".                   
                                         jRadioButton1.setText(                               "Under-Graduate"                               );                   
                             
                                         // Setting text of "jRadioButton4".                   
                                         jRadioButton2.setText(                               "Graduate"                               );                   
                             
                                         // Setting Bounds of "jRadioButton2".                   
                                         jRadioButton1.setBounds(                               120                               ,                               30                               ,                               120                               ,                               50                               );                   
                             
                                         // Setting Bounds of "jRadioButton4".                   
                                         jRadioButton2.setBounds(                               250                               ,                               30                               ,                               80                               ,                               50                               );                   
                             
                                         // Setting Bounds of "jButton".                   
                                         jButton.setBounds(                               125                               ,                               90                               ,                               80                               ,                               30                               );                   
                             
                                         // Setting Bounds of JLabel "L2".                   
                                         L1.setBounds(                               20                               ,                               30                               ,                               150                               ,                               50                               );                   
                             
                                         // "this" keyword in java refers to current object.                   
                                         // Adding "jRadioButton2" on JFrame.                   
                                         this                               .add(jRadioButton1);                   
                             
                                         // Adding "jRadioButton4" on JFrame.                   
                                         this                               .add(jRadioButton2);                   
                             
                                         // Adding "jButton" on JFrame.                   
                                         this                               .add(jButton);                   
                             
                                         // Adding JLabel "L2" on JFrame.                   
                                         this                               .add(L1);                   
                             
                                         // Adding "jRadioButton1" and "jRadioButton3" in a Button Group "G2".                   
                                         G1.add(jRadioButton1);                   
                                         G1.add(jRadioButton2);                   
                                         }                   
                     }                   
                             
                     class                               RadioButton {                   
                                         // Driver code.                   
                                         public                               static                               void                               main(String args[])                   
                                         {                               // Creating object of demo class.                   
                                         Demo f =                               new                               Demo();                   
                             
                                         // Setting Bounds of JFrame.                   
                                         f.setBounds(                               100                               ,                               100                               ,                               400                               ,                               200                               );                   
                             
                                         // Setting Title of frame.                   
                                         f.setTitle(                               "RadioButtons"                               );                   
                             
                                         // Setting Visible status of frame as true.                   
                                         f.setVisible(                               true                               );                   
                                         }                   
                     }                   

输出：

程序2：带有ActionListener的JRadioButton

                     // Java program to show JRadioButton Example.                   
                     // in java. Importing different Package.                   
                     import                               java.awt.*;                   
                     import                               javax.swing.*;                   
                     import                               java.awt.event.*;                   
                             
                     class                               Demo                               extends                               JFrame {                   
                             
                                         // Declaration of object of JRadioButton class.                   
                                         JRadioButton jRadioButton1;                   
                             
                                         // Declaration of object of JRadioButton class.                   
                                         JRadioButton jRadioButton2;                   
                             
                                         // Declaration of object of JButton class.                   
                                         JButton jButton;                   
                             
                                         // Declaration of object of ButtonGroup class.                   
                                         ButtonGroup G1;                   
                             
                                         // Declaration of object of  JLabel  class.                   
                                         JLabel L1;                   
                             
                                         // Constructor of Demo class.                   
                                         public                               Demo()                   
                                         {                   
                             
                                         // Setting layout as null of JFrame.                   
                                         this                               .setLayout(                               null                               );                   
                             
                                         // Initialization of object of "JRadioButton" class.                   
                                         jRadioButton1 =                               new                               JRadioButton();                   
                             
                                         // Initialization of object of "JRadioButton" class.                   
                                         jRadioButton2 =                               new                               JRadioButton();                   
                             
                                         // Initialization of object of "JButton" class.                   
                                         jButton =                               new                               JButton(                               "Click"                               );                   
                             
                                         // Initialization of object of "ButtonGroup" class.                   
                                         G1 =                               new                               ButtonGroup();                   
                             
                                         // Initialization of object of " JLabel" class.                   
                                         L1 =                               new                               JLabel(                               "Qualification"                               );                   
                             
                                         // setText(...) function is used to set text of radio button.                   
                                         // Setting text of "jRadioButton2".                   
                                         jRadioButton1.setText(                               "Under-Graduate"                               );                   
                             
                                         // Setting text of "jRadioButton4".                   
                                         jRadioButton2.setText(                               "Graduate"                               );                   
                             
                                         // Setting Bounds of "jRadioButton2".                   
                                         jRadioButton1.setBounds(                               120                               ,                               30                               ,                               120                               ,                               50                               );                   
                             
                                         // Setting Bounds of "jRadioButton4".                   
                                         jRadioButton2.setBounds(                               250                               ,                               30                               ,                               80                               ,                               50                               );                   
                             
                                         // Setting Bounds of "jButton".                   
                                         jButton.setBounds(                               125                               ,                               90                               ,                               80                               ,                               30                               );                   
                             
                                         // Setting Bounds of JLabel "L2".                   
                                         L1.setBounds(                               20                               ,                               30                               ,                               150                               ,                               50                               );                   
                             
                                         // "this" keyword in java refers to current object.                   
                                         // Adding "jRadioButton2" on JFrame.                   
                                         this                               .add(jRadioButton1);                   
                             
                                         // Adding "jRadioButton4" on JFrame.                   
                                         this                               .add(jRadioButton2);                   
                             
                                         // Adding "jButton" on JFrame.                   
                                         this                               .add(jButton);                   
                             
                                         // Adding JLabel "L2" on JFrame.                   
                                         this                               .add(L1);                   
                             
                                         // Adding "jRadioButton1" and "jRadioButton3" in a Button Group "G2".                   
                                         G1.add(jRadioButton1);                   
                                         G1.add(jRadioButton2);                   
                             
                                         // Adding Listener to JButton.                   
                                         jButton.addActionListener(                               new                               ActionListener() {                   
                                         // Anonymous class.                   
                             
                                         public                               void                               actionPerformed(ActionEvent e)                   
                                         {                   
                                         // Override Method                   
                             
                                         // Declaration of String class Objects.                   
                                         String qual =                               " "                               ;                   
                             
                                         // If condition to check if jRadioButton2 is selected.                   
                                         if                               (jRadioButton1.isSelected()) {                   
                             
                                         qual =                               "Under-Graduate"                               ;                   
                                         }                   
                             
                                         else                               if                               (jRadioButton2.isSelected()) {                   
                             
                                         qual =                               "Graduate"                               ;                   
                                         }                   
                                         else                               {                   
                             
                                         qual =                               "NO Button selected"                               ;                   
                                         }                   
                             
                                         // MessageDialog to show information selected radion buttons.                   
                                         JOptionPane.showMessageDialog(Demo.                               this                               , qual);                   
                                         }                   
                                         });                   
                                         }                   
                     }                   
                             
                     class                               RadioButton {                   
                                         // Driver code.                   
                                         public                               static                               void                               main(String args[])                   
                                         {                               // Creating object of demo class.                   
                                         Demo f =                               new                               Demo();                   
                             
                                         // Setting Bounds of JFrame.                   
                                         f.setBounds(                               100                               ,                               100                               ,                               400                               ,                               200                               );                   
                             
                                         // Setting Title of frame.                   
                                         f.setTitle(                               "RadioButtons"                               );                   
                             
                                         // Setting Visible status of frame as true.                   
                                         f.setVisible(                               true                               );                   
                                         }                   
                     }                   

输出：

按下“点击”按钮后。

Program 3程序创建一组简单的单选按钮（带有图像），并向其添加项目侦听器

                     // Java Program to create a simple group of radio buttons                   
                     // (with image )and add item listener to them                   
                     import                               java.awt.event.*;                   
                     import                               java.awt.*;                   
                     import                               javax.swing.*;                   
                     class                               solve                               extends                               JFrame                               implements                               ItemListener {                   
                             
                                         // frame                   
                                         static                               JFrame f;                   
                             
                                         // radiobuttons                   
                                         static                               JRadioButton b, b1;                   
                             
                                         // create a label                   
                                         static                               JLabel l1;                   
                             
                                         // main class                   
                                         public                               static                               void                               main(String[] args)                   
                                         {                   
                                         // create a new frame                   
                                         f =                               new                               JFrame(                               "frame"                               );                   
                             
                                         // create a object                   
                                         solve s =                               new                               solve();                   
                             
                                         // create a panel                   
                                         JPanel p =                               new                               JPanel();                   
                             
                                         // create a new label                   
                                         JLabel l =                               new                               JLabel(                               "which website do you like?"                               );                   
                                         l1 =                               new                               JLabel(                               "geeksforgeeks selected"                               );                   
                             
                                         // create Radio buttons                   
                                         b =                               new                               JRadioButton(                               "geeksforgeeks"                               ,                               new                               ImageIcon(                               "f:/gfg.jpg"                               ));                   
                                         b1 =                               new                               JRadioButton(                               "others"                               );                   
                             
                                         // create a button group                   
                                         ButtonGroup bg =                               new                               ButtonGroup();                   
                             
                                         // add item listener                   
                                         b.addItemListener(s);                   
                                         b1.addItemListener(s);                   
                             
                                         // add radio buttons to button group                   
                                         bg.add(b);                   
                                         bg.add(b1);                   
                             
                                         b.setSelected(                               true                               );                   
                             
                                         // add button and label to panel                   
                                         p.add(l);                   
                                         p.add(b);                   
                                         p.add(b1);                   
                                         p.add(l1);                   
                             
                                         f.add(p);                   
                             
                                         // set the size of frame                   
                                         f.setSize(                               400                               ,                               400                               );                   
                             
                                         f.show();                   
                                         }                   
                             
                                         public                               void                               itemStateChanged(ItemEvent e)                   
                                         {                   
                                         if                               (e.getSource() == b) {                   
                                         if                               (e.getStateChange() ==                               1                               ) {                   
                                         l1.setText(                               "geeksforgeeks selected"                               );                   
                                         }                   
                                         }                   
                                         else                               {                   
                             
                                         if                               (e.getStateChange() ==                               1                               ) {                   
                                         l1.setText(                               "others selected"                               );                   
                                         }                   
                                         }                   
                                         }                   
                     }                   

输出： 图片[4]-JRadioButton | Java Swing-yiteyi-C++库

注意：以下程序可能无法在联机编译器中运行，请使用脱机IDE。

文章版权归作者所有，未经允许请勿转载。

THE END

Java