I had to convert one of my programs into an applet.
And most of it I copied and pasted, but the program is suppose to let the user input a number in the texfield and when they click one of the radio button options the calculate resuls are suppose to take the place of where the blue text is. i have my itemlistener code and my program compiles fine, but nothing happens when i click on the radio buttons.. Can anyone please help me figure out what I may be doing wrong?

Java file

/*
*/
/*
*/
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.applet.*;
import java.text.DecimalFormat;	// Needed for formatting decimal

public class TemperatureApplet extends JApplet implements ItemListener
{
	DecimalFormat df = new DecimalFormat("#,##0.00");
	private double fahrenheit, celsius, kelvin;
	JRadioButton optFtoC,  optFtoK, optCtoF, optCtoK, optKtoF, optKtoC, optHidden;
	JTextField txtTemp;
	JLabel lblTitle;
	JLabel lblResults;
	JLabel lblTemp;

	public void init()
	{
		// Create JLabels
	    JLabel lblTitle =  new JLabel("Temperature Conversion Calculator");
		JLabel lblTemp = new JLabel("Temperature");
		JLabel lblResults = new JLabel("Results will display here");
		// Create TextFields
		JTextField txtTemp = new JTextField(5);
    	// Create Button Group/ Radio buttons
		ButtonGroup grpOperator = new ButtonGroup();
			JRadioButton optFtoC = new JRadioButton("Fahrenheit to Celsius");
			JRadioButton optFtoK = new JRadioButton("Fahrenheit to Kelvin");
			JRadioButton optCtoF = new JRadioButton("Celsius to Fahrenheit");
			JRadioButton optCtoK = new JRadioButton("Celsius to Kelvin");
			JRadioButton optKtoF = new JRadioButton("Kelvin to fahrenheit");
			JRadioButton optKtoC = new JRadioButton("Kelvin to Celsius");
			JRadioButton optHidden = new JRadioButton("");
		// Create JPanels
		JPanel pnlTitle = new JPanel();
		JPanel pnlTemp = new JPanel();
		JPanel pnlResults= new JPanel();

		pnlTemp.setLayout(new GridLayout(1,2));
		pnlResults.setLayout(new GridLayout(3,2));

		// Add the radiobuttons to a button group
		grpOperator.add(optFtoC);
		grpOperator.add(optFtoK);
		grpOperator.add(optCtoF);
		grpOperator.add(optCtoK);
		grpOperator.add(optKtoF);
		grpOperator.add(optKtoC);
		grpOperator.add(optHidden);

		// Add objects to the panels
		pnlTitle.add (lblTitle);
		pnlTemp.add (lblTemp);
		pnlTemp.add (txtTemp);
		pnlResults.add (optFtoC);
		optFtoC.addItemListener(this);
		pnlResults.add (optFtoK);
		optFtoK.addItemListener(this);
		pnlResults.add (optCtoF);
		optCtoF.addItemListener(this);
		pnlResults.add (optCtoK);
		optCtoK.addItemListener(this);
		pnlResults.add (optKtoF);
		optKtoF.addItemListener(this);
		pnlResults.add (optKtoC);
		optKtoC.addItemListener(this);
		pnlResults.add (lblResults);
		lblResults.setForeground(Color.blue);

		Container content = getContentPane();
		content.setLayout(new BorderLayout());
		content.add(pnlTitle,BorderLayout.NORTH);
		content.add(pnlTemp, BorderLayout.CENTER);
		content.add(pnlResults, BorderLayout. SOUTH);

	}// End init

	public void itemStateChanged(ItemEvent choice)
	{
		if (choice.getStateChange() == ItemEvent.SELECTED)
		{
			if (optFtoC.isSelected()==true)
			{fToC();}
			else if (optFtoK.isSelected()==true)
			{fToK();}
			else if (optCtoK.isSelected()==true)
			{cToK();}
			else if (optCtoF.isSelected()==true)
			{cToF();}
			else if (optKtoF.isSelected()==true)
			{kToF();}
			else if (optKtoC.isSelected()==true)
			{kToC();}
		}
	}//End ItemStateChanged

	//Celsius to Fahrenheit converter method
	private void cToF()
	{
		try
		{
			celsius = Double.parseDouble(txtTemp.getText());
			fahrenheit = (celsius * (9.0/5.0)) + 32;
			lblResults.setText("Results:  " + df.format(fahrenheit));
		}
		catch(NumberFormatException e)
		{
			JOptionPane.showMessageDialog(null,"Please enter a valid numeric number","Error",JOptionPane.ERROR_MESSAGE);
			clearIt();
		}
	}// end cToF
		//Fahrenheit to Celsius Converter method
	private void fToC()
	{
		try
		{
			fahrenheit = Double.parseDouble(txtTemp.getText());
			celsius = (5.0/9.0) * (fahrenheit - 32);
			lblResults.setText("Results:  " + df.format(celsius));
		}
		catch(NumberFormatException e)
		{
			JOptionPane.showMessageDialog(null,"Please enter a valid numeric number","Error",JOptionPane.ERROR_MESSAGE);
			clearIt();
		}
	}// end fToC
		// Celsius to Kelvin converter method
	private void cToK()
	{
		try
		{
			celsius = Double.parseDouble(txtTemp.getText());
			kelvin = celsius + 273.15;
			lblResults.setText("Results:  " + df.format(kelvin));
		}
		catch(NumberFormatException e)
		{
			JOptionPane.showMessageDialog(null,"Please enter a valid numeric number","Error",JOptionPane.ERROR_MESSAGE);
			clearIt();
		}
	}// end cToK
		// Fahrenheit to Kelvin converter method
	private void fToK()
	{
		try
		{
			fahrenheit = Double.parseDouble(txtTemp.getText());
			kelvin = ((5.0/9.0) * (fahrenheit - 32)) + 273.15;
			lblResults.setText("Results:  " + df.format(kelvin));
		}
		catch(NumberFormatException e)
		{
			JOptionPane.showMessageDialog(null,"Please enter a valid numeric number","Error",JOptionPane.ERROR_MESSAGE);
			clearIt();
		}
	}// end fToK
		// Kelvin to Fahrenheit converter method
	private void kToF()
	{
		try
		{
			kelvin = Double.parseDouble(txtTemp.getText());
			fahrenheit = 	((9.0/5.0) * (kelvin - 273.15)) + 32;
			lblResults.setText("Results:  " + df.format(fahrenheit));
		}
		catch(NumberFormatException e)
		{
			JOptionPane.showMessageDialog(null,"Please enter a valid numeric number","Error",JOptionPane.ERROR_MESSAGE);
			clearIt();
		}
	}// end kToF
	// Kelvin to celsius converter method
	private void kToC()
	{
		try
		{
			kelvin = Double.parseDouble(txtTemp.getText());
			celsius = kelvin - 273.15;
			lblResults.setText("Results:  " + df.format(celsius));
		}
		catch(NumberFormatException e)
		{
			JOptionPane.showMessageDialog(null,"Please enter a valid numeric number","Error",JOptionPane.ERROR_MESSAGE);
			clearIt();
		}
	}// end kToC
	//Clear textfield, radiobutton selection, and results
	private void clearIt()
	{
		txtTemp.setText(" ");
		optHidden.setSelected(true);
		lblResults.setText("Results will display here");
	}// end clearIt


}// End class

html file

<html>
<body>
<applet code = "TemperatureApplet.class" width = "500" height = "130">
</applet>
</body>
</html>

Edited 6 Years Ago by jko2326: n/a

At first glace it seem that all the JRadioButton(s) (optFtoC, optFtoK, optCtoF, optCtoK, optKtoF, optKtoC, optHidden;) are not inittilized:
because you delare the buttons you see are those declared in the init function.

So make this change in the init function

// Create Button Group/ Radio buttons
        ButtonGroup grpOperator = new ButtonGroup();
             optFtoC = new JRadioButton("Fahrenheit to Celsius");
             optFtoK = new JRadioButton("Fahrenheit to Kelvin");
             optCtoF = new JRadioButton("Celsius to Fahrenheit");
             optCtoK = new JRadioButton("Celsius to Kelvin");
             optKtoF = new JRadioButton("Kelvin to fahrenheit");
             optKtoC = new JRadioButton("Kelvin to Celsius");
             optHidden = new JRadioButton("");

hope it helps

Edited 3 Years Ago by mike_2000_17: Fixed formatting

the same think about txtTemp, ilbTemp etc..

// Create JLabels
	     lblTitle =  new JLabel("Temperature Conversion Calculator");
		 lblTemp = new JLabel("Temperature");
		 lblResults = new JLabel("Results will display here");
		// Create TextFields
		 txtTemp = new JTextField(5);
    	// Create Button Group/ Radio buttons
		ButtonGroup grpOperator = new ButtonGroup();
			 optFtoC = new JRadioButton("Fahrenheit to Celsius");
			 optFtoK = new JRadioButton("Fahrenheit to Kelvin");
			 optCtoF = new JRadioButton("Celsius to Fahrenheit");
			 optCtoK = new JRadioButton("Celsius to Kelvin");
			 optKtoF = new JRadioButton("Kelvin to fahrenheit");
			 optKtoC = new JRadioButton("Kelvin to Celsius");
			 optHidden = new JRadioButton("");

the same think about txtTemp, ilbTemp etc..

// Create JLabels
	     lblTitle =  new JLabel("Temperature Conversion Calculator");
		 lblTemp = new JLabel("Temperature");
		 lblResults = new JLabel("Results will display here");
		// Create TextFields
		 txtTemp = new JTextField(5);
    	// Create Button Group/ Radio buttons
		ButtonGroup grpOperator = new ButtonGroup();
			 optFtoC = new JRadioButton("Fahrenheit to Celsius");
			 optFtoK = new JRadioButton("Fahrenheit to Kelvin");
			 optCtoF = new JRadioButton("Celsius to Fahrenheit");
			 optCtoK = new JRadioButton("Celsius to Kelvin");
			 optKtoF = new JRadioButton("Kelvin to fahrenheit");
			 optKtoC = new JRadioButton("Kelvin to Celsius");
			 optHidden = new JRadioButton("");

Sorry about the imoticon above I did not now why and hwo it is in my post.
it mean nothing.
Sorry

This question has already been answered. Start a new discussion instead.