I'm fairly new to Java and I've been having some difficulties with Swing. I'm trying to create a very simple GUI program which should be create a set of buttons but my code doesn't work.
Here's my code;
myPanel = new JPanel();
JButton myButton = new JButton("create buttons");
myButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
int val = Integer.parseInt(textfield.getText());
for(int i = 0; i < val; i++) {
JButton button = new JButton("");
button.setText(String.valueOf(i));
myPanel.add(button);
}
}
});
But nothing happens when I click to "create buttons" button. Can anyone tell me w开发者_如何学Gohat I'm missing?
You need to refresh panels that are already running with revalidate:
myPanel.revalidate()
You might have to invoke the validate
method on the myPanel
to get the contents of the GUI to update, after adding a button on the panel. Also consider the use of IDEs(Netbeans, Eclipse, IntelliJ Idea etc...), that's if it's necessary, for GUI building.
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