Java Pop-Up Window to Ask for Data

What code would I use to ask a user to enter their grade into a pop-up window?

When a JButton is pressed, I want a little box to pop-up and prompt the user to enter their grade. Furthermore, would it be possible to get th开发者_开发问答e value of the entered double value?

Thanks for all your time. I appreciate it!

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Use JOptionPane.showInputDialog().

You can find a nice tutorial at: http://download.oracle.com/javase/tutorial/uiswing/components/dialog.html#input

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You want a JOptionPane. Use something like the following code snippet inside the JButton's ActionListener:

            JTextArea textArea = new JTextArea();
            textArea.setEditable(true);
            JScrollPane scrollPane = new JScrollPane(textArea);
            scrollPane.requestFocus();
            textArea.requestFocusInWindow();
            scrollPane.setPreferredSize(new Dimension(800, 600));
            JOptionPane.showMessageDialog(
                    (ControlWindow) App.controller.control, scrollPane,
                    "Paste Info", JOptionPane.PLAIN_MESSAGE);
            String info = textArea.getText();

You could parse/validate the double value from the output string. You could also use different swing components - this example is a scrollable text area.

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The simplest approach would perhaps be to use JoptionPane.showInputDialog(...). However, be aware that it will crash if someone tries to enter anything other than a double.

@Override
public void actionPerformed(ActionEvent actionEvent) {
    double someNumber = Double.parseDouble(
            JOptionPane.showInputDialog(this, "Type in grade:"));
}