通过Dimension将JFrame最大化到屏幕大小

Question

All I can think is that I'm not setting the screen size correctly. Logs show that the height and width look correct. From the Swing trail :

package net.bounceme.dur.nntp.swing;

import java.awt.Dimension;
import java.awt.Toolkit;
import java.util.logging.Logger;
import javax.swing.*;
import java.awt.*;

public class HelloWorldSwing {

    private static final Logger LOG = Logger.getLogger(HelloWorldSwing.class.getName());

    private static void createAndShowGUI() {
        //Create and set up the window.
        JFrame frame = new JFrame("HelloWorldSwing");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);


       // Container c = frame.getContentPane();
//        frame.getContentPane();
      //  c.setBackground(Color.YELLOW);
        // adjust to need.
        Dimension d = new Dimension(400, 40);
        //c.setPreferredSize(d);

        //Add the ubiquitous "Hello World" label.
        JLabel label = new JLabel("Hello World");
        frame.getContentPane().add(label);

        Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
        int height = screenSize.height - 50;
        int width = screenSize.width - 50;
        frame.setSize(height, width);
        frame.setSize(d);
        LOG.info(height + "\t\t\t" + width);
        //Display the window.
        frame.pack();
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        //Schedule a job for the event-dispatching thread:
        //creating and showing this application's GUI.
        javax.swing.SwingUtilities.invokeLater(new Runnable() {

            public void run() {
                createAndShowGUI();
            }
        });
    }
}

obligatory legal boilerplate:

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/**
 * This example, like all Swing examples, exists in a package:
 * in this case, the "start" package.
 * If you are using an IDE, such as NetBeans, this should work 
 * seamlessly.  If you are compiling and running the examples
 * from the command-line, this may be confusing if you aren't
 * used to using named packages.  In most cases,
 * the quick and dirty solution is to delete or comment out
 * the "package" line from all the source files and the code
 * should work as expected.  For an explanation of how to
 * use the Swing examples as-is from the command line, see
 * http://docs.oracle.com/javase/javatutorials/tutorial/uiswing/start/compile.html#package
 */

screenshot:

Answer 1

Try removing frame.pack(); . This gives expanded frame. This is because pack() causes the frame to be re-sized .

Answer 2

1. Toolkit.getDefaultToolkit().getScreenSize() doesn't take into consideration any additional insets of things like the task/dock bar
2. You're calling JFrame#pack , which is going to resize the frame to the preferred size of its contents

You should be using JFrame#setExtendedState(JFrame.MAXIMIZED_BOTH)

Answer 3

You should comment this line in your code:

//frame.setSize(d);

Also remove this line:

//frame.pack();

Answer 4

Remove the pack() call. And try setting all three methods being setSize() , setPrefferredSize() and setMaximumSize() with the same dimension.

Answer 5

Just to note for those just finding this,

frame.setSize(height, width);

Is backwards, it should have been:

frame.setSize(width, height);

Otherwise you will quickly notice when you run the program (unless you have a square screen) your JFrame won't cover part of the right side of your screen.

Also, remove this part of the code to see the JFrame attempt to take up most of the screen (I get most of my screen on a 28" monitor with the above code (without frame.pack() ):

frame.setSize(d);

The above snippet of code is changing you JFrame to the width 400, height 40 that was defined in Dimension d.

Answer 6

试试这个，

this.setExtendedState(MAXIMIZED_BOTH);