问题
Here you will see my code: I am just trying to make a little window that displays "Hello, Java!".
I am currently running on Ubuntu 14.04. To go more in depth with my problem, the icon with the coffee cup shows up when I run the program like there is a window, but there is not window attached to it and if clicked, no window pops up.
Any help would be much appreciated!
public class HelloJava1 extends javax.swing.JComponent
{
public static void main(String[] args)
{
javax.swing.JFrame f = new javax.swing.JFrame("HelloJava1");
f.setSize(300, 300);
f.getContentPane().add(new HelloJava1());
f.setVisible(true);
}
public void paintComponent(java.awt.Graphics g)
{
g.drawString("Hello, Java!", 125, 95);
}
}
Additionally, I am compiling via command line using javac HelloJava1.java and running using java HelloJava1.
I am writing the code via gedit.
回答1:
This code should work reliably:
import java.awt.*;
import javax.swing.*;
public class HelloJava1 extends JComponent {
public static void main(String[] args) {
Runnable r = new Runnable() {
public void run() {
JFrame f = new JFrame("HelloJava1");
// f.setSize(300, 300); better to pack() the frame
f.getContentPane().add(new HelloJava1());
// pack should be AFTER components are added..
f.pack();
f.setVisible(true);
}
};
// Swing GUIs should be created and updated on the EDT
SwingUtilities.invokeLater(r);
}
@Override // good practice..
public void paintComponent(java.awt.Graphics g) {
// always call super method 1st!
super.paintComponent(g);
g.drawString("Hello, Java!", 125, 95);
}
// instead of setting the size of components, it is
// better to override the preferred size.
@Override
public Dimension getPreferredSize() {
return new Dimension(300,300);
}
}
来源:https://stackoverflow.com/questions/25965176/jframe-code-compiles-and-runs-but-does-not-open-window