What am i doing wrong in retrieving value of button group?

问题

import javax.swing.*;
import javax.swing.event.*; 
import java.awt.*;
import java.awt.event.*;
import net.java.dev.designgridlayout.DesignGridLayout;
import java.sql.*;

class databaseprob 
{
JFrame JF;
Container C,C1;
JDesktopPane JDP;
JInternalFrame JIF5;
JLabel i1l1,i1l2;
JTextField i1t1;
JRadioButton i1r1,i1r2,i1r3,i1r4;
JButton i1b1,i1b2,i1b3;
JInternalFrame JIF1;
ButtonGroup i1bg;
String i1type;


public databaseprob()
{
JF = new JFrame();
JDP = new JDesktopPane();
JF.setVisible(true);
JF.pack();


    JIF1 = new JInternalFrame("Register",true,true, true, true);
C=JF.getContentPane();
C.add(JDP,BorderLayout.CENTER);
JIF1.setVisible(true);
JIF1.setBounds(10, 10, 600, 500); 
    C1 = JIF1.getContentPane();
DesignGridLayout layout = new DesignGridLayout(C1);



    i1l1 = new JLabel("Head ID : ");
    i1l2 = new JLabel("Type : ");

    i1t1 = new JTextField(10);


    i1bg = new ButtonGroup();
    ActionListener actionListener = new ActionListener() { @Override
        public void actionPerformed(ActionEvent e) {
                JRadioButton radioButton = (JRadioButton)e.getSource();
                i1type = radioButton.getText();
                System.out.println(i1type);
            }
        };
    i1r1 = new JRadioButton("Customer");
    i1r1.addActionListener(actionListener);
    i1bg.add(i1r1);

    i1r2 = new JRadioButton("Supplier");
    i1r2.addActionListener(actionListener);
    i1bg.add(i1r2);

    i1r3 = new JRadioButton("Staff");
    i1r3.addActionListener(actionListener);
    i1bg.add(i1r3);

    i1r4 = new JRadioButton("Others");
    i1r4.addActionListener(actionListener);
    i1bg.add(i1r4);






   i1b1 = new JButton("Save");
i1b1.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent ae)
    {
            try
        {
        Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
        Connection i1conn =   DriverManager.getConnection("Jdbc:Odbc:TomsJava");

        int i1headID = Integer.parseInt(i1t1.getText());


        Statement i1stmt = i1conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_UPDATABLE);
        ResultSet i1rs = i1stmt.executeQuery("SELECT * FROM i1Register");
        i1rs.moveToInsertRow();
        i1rs.updateInt("Head_ID", i1headID);
        i1rs.updateString("Type",i1type);

        i1rs.insertRow();   
        i1stmt.close();
        i1rs.close();
        }       

    catch(SQLException e)
    {
    System.out.println(e);
    }
    catch(ClassNotFoundException z)
    {
    System.out.println(z);
    }
    catch(NumberFormatException n)
    {
    System.out.println(n);
    }
    }
});

   i1b2 = new JButton("Reset");
   i1b3 = new JButton("Close");



layout.row().grid(i1l1).add(i1t1);
layout.row().grid(i1l2).add(i1r1).add(i1r2).add(i1r3).add(i1r4);

layout.emptyRow();
layout.row().center().add(i1b1).add(i1b2).add(i1b3);

JDP.add(JIF1);
}
public static void main(String args[])
{
new databaseprob();
}
}

Seems this code is updating the database. Suggest me any more changes i should make. The variable declaration was creating the problem i guess, the String i1type was declared inside radiobutton and wasnt available for Save Button.

回答1:

My problem is that i am trying to retrieve value of radiobutton in String format.

In first place this line won't even compile:

String i1type = i1bg.isSelected();

Because:

ButtonGroup.isSelected(ButtonModel model) requires a ButtonModel as argument.
This method returns a boolean which you're trying to assig to a String variable.

You can achieve your goal by implementing an ActionListener as described in How to Use Buttons, Check Boxes, and Radio Buttons tutorial and attaching this action listener to your radio buttons. For instance:

ActionListener actionListener = new ActionListener() {
    @Override
    public void actionPerformed(ActionEvent e) {
        JRadioButton radioButton = (JRadioButton)e.getSource();
        String selectedOption = radioButton.getText();
        System.out.println(selectedOption );
    }
};

i1r1.addActionListener(actionListener);
i1r2.addActionListener(actionListener);
...

If the value you need and radio buttons text may differ then you can use putClientProperty() method (inherited from JComponent) as exemplified in this answer.

回答2:

isSelected (you're missing some arguments) determines if any radiobutton is selected in the ButtonGroup.

You need getSelection

if (i1bg.getSelection() != null) {
   String i1type = i1bg.getSelection().getActionCommand();
   ...
}

For this to work the ActionCommand needs to be explicitly set for the radio button

回答3:

You forgot to add your JRadioButtons to the ButtonGroup.

来源：https://stackoverflow.com/questions/22072834/what-am-i-doing-wrong-in-retrieving-value-of-button-group

标签

java

swing

jradiobutton

buttongroup