How to use GridBagLayout ()

GridBagLayout is one of the most important layout managers in Java, can make a very complex layout, can say that gridbaglayout is necessary to learn,

GridBagLayoutClass is a flexible layout manager that does not require components to be of the same size to align components vertically, horizontally, or along their baselines.

Each GridBagLayout object maintains a dynamic rectangular cell grid, each of which occupies one or more of these units, which is called the display area .

Here is a Notepad case to illustrate how gridbaglayout is used.

Analysis:

A description with arrows can be stretched.

4 occupies 4 compartments and 6 occupies 4 compartments. If the setting 6 can be stretched, then 4 will also be stretched.

However, if you set the 4 stretch, the 7 column can also be stretched, so 4 cannot set the extrusion. We should set 4 to be followed by 6 for stretching.

The Gray line is to see the approximate layout, the number of squares occupied by the component.

Run-time display effect

Import Java.awt.*;import javax.swing.*;p ublic class Gridbagdemo extends JFrame {public static void main (String args[])    {Gridbagdemo demo = new Gridbagdemo ();        } public Gridbagdemo () {init ();        This.setsize (600,600);    This.setvisible (TRUE);        } public void Init () {J1 = new JButton ("open");        J2 = new JButton ("Save");        J3 = new JButton ("Save As");        J4 = new JPanel ();        string[] str = {"Java notes", "C # Notes", "HTML5 Notes"};        J5 = new JComboBox (str);        J6 = new JTextField ();        J7 = new JButton ("Empty");        J8 = new JList (str);　　　　 J9 = new JTextArea ();        J9.setbackground (Color.pink);//To see the effect, set the color gridbaglayout layout = new GridBagLayout ();        This.setlayout (layout);        This.add (J1);//Add components into JFrame this.add (J2);        This.add (J3);        This.add (J4);        This.add (J5);        This.add (J6);        This.add (J7);        This.add (J8);        This.add (J9); Gridbagconstraints s= New GridBagconstraints ();//defines a gridbagconstraints,//is used to control the display position of the added component S.fill = Gridbagconstraints.both;        This method is intended to set the display condition if the component's region is larger than the component itself//none: The component size is not resized.        Horizontal: Widens the component so that it fills its display area horizontally, but does not change the height.        VERTICAL: The heightening component, which fills its display area vertically, but does not change the width.        BOTH: Causes the component to fully fill its display area. s.gridwidth=1;//the method is to set the number of squares occupied by the component level, if 0, it means that the component is the last s.weightx of the line = 0;//The method sets the horizontal stretch of the component, if 0 does not stretch, 0 is stretched as the window grows,        Between 0 and 1 s.weighty=0;//the method sets the vertical stretch amplitude of the component, if 0 means no stretch, 0 is stretched as the window grows, between 0 and 1 layout.setconstraints (J1, s);//Set component        s.gridwidth=1;        S.WEIGHTX = 0;        s.weighty=0;        Layout.setconstraints (J2, s);        s.gridwidth=1;        S.WEIGHTX = 0;        s.weighty=0;        Layout.setconstraints (J3, s); s.gridwidth=0;//the method is to set the number of squares occupied by the component level, if 0, it means that the component is the last s.weightx of the row = 0;//cannot be 4 for 1,J4, and can be stretched horizontally,//But if 1, the following row of columns        The lattice will also follow the stretching, resulting in the J7 column can also be stretched//so should be followed by J6 stretching s.weighty=0;    Layout.setconstraints (J4, s); s.gridwidth=2;    S.WEIGHTX = 0;        s.weighty=0;        Layout.setconstraints (J5, s);        ; s.gridwidth=4;        S.WEIGHTX = 1;        s.weighty=0;        Layout.setconstraints (J6, s);        ; s.gridwidth=0;        S.WEIGHTX = 0;        s.weighty=0;        Layout.setconstraints (J7, s);        ; s.gridwidth=2;        S.WEIGHTX = 0;        S.weighty=1;        Layout.setconstraints (J8, s);        ; s.gridwidth=5;        S.WEIGHTX = 0;        S.weighty=1;    Layout.setconstraints (J9, s);    } JButton J1;    JButton J2;    JButton J3;    JPanel J4;    JComboBox J5;    JTextField J6;    JButton J7;    JList J8; JTextArea J9;}

　　

How to use GridBagLayout ()