Java graphical interface design--null layout of layout manager (empty layout)

The general container has a default layout, but sometimes you need to specify the size and location of each build, and you need to use an empty layout.

Operation Method:

1) First Use the setlayout (NULL) statement to set the container's layout to a null layout (empty layout).

2) re-call the component's setbounds (int x, int y, int width,int height) method to set the size and position of the component in the container, in pixels.

X is the distance of the left edge of the control from the left edge of the form

Y is the distance of the top edge of the control from the top edge of the form

Width for control widths

Height for control Heights

Example: Using an empty layout to pinpoint the position of a component

Nulllayoutdemo.java

Import java.awt.*;

Import javax.swing.*;

public class nulllayoutdemo{

JFrame fr;

JButton A, B;

Nulllayoutdemo () {

FR = new JFrame ();

Fr.setbounds (100,100,250,150);

Set form to empty layout

Fr.setlayout (NULL);

A=new JButton ("button A");

B=new JButton ("button B");

Fr.getcontentpane (). Add (a);

Set the exact position of button a

A.setbounds (30,30,80,25);

Fr.getcontentpane (). Add (b);

B.setbounds (150,40,80,25);

Fr.settitle ("Nulllayoutdemo");

Fr.setvisible (TRUE);

Fr.setdefaultcloseoperation (Jframe.exit_on_close);

Fr.setlocationrelativeto (NULL); To center the form on the display

}

public static void Main (String args[]) {

New Nulllayoutdemo ();

}

}

The results of the program run as follows:

Java graphical interface design--null layout of layout manager (empty layout)