Java Code Issuses

Ziycon

i am writing a prog for a college CA and i need to swicth from one screen to another, the prog is written in java and the screens are done in javax.swing and java.awt, i want the current windows to close and the corresponding one to appear when i click on the right button!??

Anyone help?

BrokenArrows

to close the current window you call dispose();

to open a new window you do the following:

McFadden.MainWindow.mainWindow MW = new McFadden.MainWindow.mainWindow();
MW.show();

In this example "McFadden.Mainwindow" is the package name and mainWindow is the class. If you are not using packages then you simply do

mainWindow MW = new mainWindow();
MW.show();

Ziycon

Nice one, you saved my ass!

BrokenArrows

no problem. i ask enough questions in here. its about time i started answering a few.

Ziycon

this is the class that i want to close but when i click on the button it does nothing, any ideas?


public void actionPerformed(ActionEvent e)
{
JButton clickedButton=(JButton)e.getSource();
String buttonText=clickedButton.getText();

if (buttonText.equals("Cancel"))
{
dispose();
}
.....etc

HaVoC

have you added an ActionListener to the button cancel ?
i.e. in your constructor for the frame:
btnCancel.addActionListener(this);

Ziycon

Ye, i have the ActionListener implemented in the class and added to the cancel button! But i still have the problem!

BrokenArrows

Is your public void actionPerformed(ActionEvent e) being used specifically for the cancel button.

If so then there is no need to check if the buttontext = cancel

Try this, this is just the way i have it set up in one of my programs. You should be able to easily modify it.

jCancelButton.setText("Cancel");
jCancelButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e)
{
jCancelButton_actionPerformed(e);
}
});

this is the jCancelButton_actionPerformed(e); part

private void jCancelButton_actionPerformed(ActionEvent e)
{
dispose():
}

This is a very effective and simple way to imlement this. If you want to open a new window after clicking the cancel button just ass the code shown in the previous post to the JCancelButton_actionPerformed(e); function. Hope this clarifys everything.

HaVoC

no idea, try doing System.out.println()'s or step through it with your ide and see if actionPerformed is being called and if it is , is it going into your if statement.
Instead of comparing the text ya might wanna try this:
if (e.getSource() == btnCancel)
{
dispose();
}

Ziycon

neither of dem worked! everything is working but da dispose function the way i have it set up! there is more then one item in the actionPerformed method!

stress :mad:

aidan_walsh

Can we see the new code?

Ziycon

There any ideas?

public void actionPerformed(ActionEvent e)
{
JButton clickedButton=(JButton)e.getSource();
String buttonText=clickedButton.getText();

if (buttonText.equals("Cancel"))
{
dispose();
}

else if (buttonText.equals("Submit"))
{
if (discDefault != true)
{
try
{
double inputDisc = Double.parseDouble(txtOther.getText());

if ((inputDisc > 0) && (inputDisc < 100))
{
discount = inputDisc;
System.out.println(discount);
}

else
System.out.println("Improper Discount!!!");
}

catch (NumberFormatException nfe)
{
System.out.println("Invalid Discount Value entered!");
}
}

else
{ System.out.println(discount); } //PRINTOUT DISCOUNT
}
}


Also can anyone tell me what type of exception do i put into the brackets of the catch block for the below??
*dbconn.connect(); is calling a method which logs into an oracle databse over a network.

try
{
dbconn.connect();
}
catch()
{
JOptionPane.showMessageDialog(null, "An error occured will trying to connect to server", "Connection Error #01", JOptionPane.WARNING_MESSAGE);
System.exit(1);
}

lynchie

Is it going into the actionPerformed method?

Have you actually aded the ActionListener i.e. called cancelButton.addActionListener(this) to your code? (Assuming cancelButton is the name of your button)

Ziycon

yes i have put in:

cancel.addActionListener(this);

pH

At the first line of the actionPerformed method put a System.out.println() and put another in the if statement. Run again with console showing and make sure that the action listener is indeed working (both prints are shown)

If both prints get shown then the problem is with the dispose, otherwise it's with the ActionListener.

bdiddy

cancelListener = new ActionListener()
{

public void actionPerformed(ActionEvent e)
{
setVisible(false);
dispose();
}
};
cancelButton.addActionListener(cancelListener);

BrokenArrows

that shouldnt make a difference bdiddy because if the frame is disposed it would automatically be taken off the screen.

All that that would accomplish is that it would hide the GUI before disposing it.

The only thing that seem to be wrong is that it does not seem to be going into the action listener.

The only wav to prove this is to do what pH said place a few System.out.println's in the code to see exactly what part is being run.

Ziycon

i'll try putting the s.o.p. lines in and come back to ya when i know what its running! tanx.