How to position the form in the center screen?

Question

I\'m a .Net developer but somehow I was task to create a simple application in java for some extra reason. I was able to create that application but my problem is how can i cent

Answer 1

public class Example extends JFrame {

public static final int WIDTH = 550;//Any Size
public static final int HEIGHT = 335;//Any Size

public Example(){

      init();

}

private void init() {

    try {
        UIManager
                .setLookAndFeel("com.sun.java.swing.plaf.nimbus.NimbusLookAndFeel");

        SwingUtilities.updateComponentTreeUI(this);
        Dimension dimension = Toolkit.getDefaultToolkit().getScreenSize();
        setSize(WIDTH, HEIGHT);

        setLocation((int) (dimension.getWidth() / 2 - WIDTH / 2),
                (int) (dimension.getHeight() / 2 - HEIGHT / 2));


    } catch (ClassNotFoundException e) {
        e.printStackTrace();
    } catch (InstantiationException e) {
        e.printStackTrace();
    } catch (IllegalAccessException e) {
        e.printStackTrace();
    } catch (UnsupportedLookAndFeelException e) {
        e.printStackTrace();
    }

}
}

Answer 2

Simply set location relative to null after calling pack on the JFrame, that's it.

e.g.,

  JFrame frame = new JFrame("FooRendererTest");
  frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
  frame.getContentPane().add(mainPanel); // or whatever...
  frame.pack();
  frame.setLocationRelativeTo(null);  // *** this will center your app ***
  frame.setVisible(true);

Answer 3

Change this:

public FrameForm() { 
    initComponents(); 
}

to this:

public FrameForm() {
    initComponents();
    this.setLocationRelativeTo(null);
}

Answer 4

Using this Function u can define your won position

setBounds(500, 200, 647, 418);

Answer 5

Actually, you dont really have to code to make the form get to centerscreen.

Just modify the properties of the jframe
Follow below steps to modify:

• right click on the form
• change FormSize policy to - generate resize code
• then edit the form position X -200 Y- 200

You're done. Why take the pain of coding. :)

Answer 6

The following example centers a frame on the screen:

package com.zetcode;

import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.GraphicsEnvironment;
import java.awt.Point;
import javax.swing.JFrame;


public class CenterOnScreen extends JFrame {

    public CenterOnScreen() {

        initUI();
    }

    private void initUI() {

        setSize(250, 200);
        centerFrame();
        setTitle("Center");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }

    private void centerFrame() {

            Dimension windowSize = getSize();
            GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment();
            Point centerPoint = ge.getCenterPoint();

            int dx = centerPoint.x - windowSize.width / 2;
            int dy = centerPoint.y - windowSize.height / 2;    
            setLocation(dx, dy);
    }


    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                CenterOnScreen ex = new CenterOnScreen();
                ex.setVisible(true);
            }
        });       
    }
}

In order to center a frame on a screen, we need to get the local graphics environment. From this environment, we determine the center point. In conjunction with the frame size, we manage to center the frame. The setLocation() is the method that moves the frame to the central position.

Note that this is actually what the setLocationRelativeTo(null) does:

public void setLocationRelativeTo(Component c) {
    // target location
    int dx = 0, dy = 0;
    // target GC
    GraphicsConfiguration gc = getGraphicsConfiguration_NoClientCode();
    Rectangle gcBounds = gc.getBounds();

    Dimension windowSize = getSize();

    // search a top-level of c
    Window componentWindow = SunToolkit.getContainingWindow(c);
    if ((c == null) || (componentWindow == null)) {
        GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment();
        gc = ge.getDefaultScreenDevice().getDefaultConfiguration();
        gcBounds = gc.getBounds();
        Point centerPoint = ge.getCenterPoint();
        dx = centerPoint.x - windowSize.width / 2;
        dy = centerPoint.y - windowSize.height / 2;
    }

  ...

  setLocation(dx, dy);
}