swing容器布局
FlowLayout
FlowLayout类是最简单的布局管理器。它按照和页面上排列单词的类似方式来安排组件----从左到右,直至没有多余的空间,然后转到下一行。
效果:
内容面板代码:
publicstaticvoid addComponentsToPane(Container pane) {
pane.setLayout(new FlowLayout());
pane.add(new JButton("Button 1"));
pane.add(new JButton("Button 2"));
pane.add(new JButton("Button 3"));
pane.add(new JButton("Long-Named Button 4"));
pane.add(new JButton("5"));
}
|
BorderLayout
一个BorderLayout对象将界面分成五大区域,分别用BorderLayout类的静态常量指定:
-PAGE_START
-PAGE_END
-LINE_START
-LINE_END
-CENTER
效果:
内容面板代码:
publicstaticvoid addComponentsToPane(Container pane) {
JButton button = new JButton("Button 1 (PAGE_START)");
pane.add(button, BorderLayout.PAGE_START);
button = new JButton("Button 2 (CENTER)");
button.setPreferredSize(new Dimension(200, 100));
pane.add(button, BorderLayout.CENTER);
button = new JButton("Button 3 (LINE_START)");
pane.add(button, BorderLayout.LINE_START);
button = new JButton("Long-Named Button 4 (PAGE_END)");
pane.add(button, BorderLayout.PAGE_END);
button = new JButton("5 (LINE_END)");
pane.add(button, BorderLayout.LINE_END);
}
|
BoxLayout
BoxLayout可以将组件由上至下或由左至右依次加入当前面板。
效果:
内容面板代码:
publicstaticvoid addComponentsToPane(Container pane) {
JPanel xPanel = new JPanel();
xPanel.setLayout(new BoxLayout(xPanel, BoxLayout.X_AXIS));
addButtons(xPanel);
JPanel yPanel = new JPanel();
yPanel.setLayout(new BoxLayout(yPanel, BoxLayout.Y_AXIS));
addButtons(yPanel);
pane.add(yPanel, BorderLayout.PAGE_START);
pane.add(xPanel, BorderLayout.PAGE_END);
}
privatestaticvoid addAButton(String text, Container container) {
JButton button = new JButton(text);
button.setAlignmentX(Component.CENTER_ALIGNMENT);
container.add(button);
}
privatestaticvoid addButtons(Container container) {
addAButton("Button 1", container);
addAButton("Button 2", container);
addAButton("Button 3", container);
addAButton("Long-Named Button 4", container);
addAButton("5", container);
}
|
CardLayout
卡片布局和其他布局不同,因为它隐藏了一些组件。卡片布局就是一组容器或者组件,它们一次仅仅显是一个,组中的每个容器称为卡片。
效果:
内容面板代码:
publicvoid addComponentToPane(Container pane) {
final JPanel contentPanel = new JPanel();
JPanel controlPanel = new JPanel();
final CardLayout cardLayout=new CardLayout();;
pane.setLayout(new BorderLayout());
pane.add(contentPanel, BorderLayout.CENTER);
pane.add(controlPanel, BorderLayout.PAGE_END);
controlPanel.setLayout(new FlowLayout());
JButton[] b = new JButton[10];
for (int i = 0; i < 10; i++) {
b[i] = new JButton("No." + i);
contentPanel.add(b[i]);
}
contentPanel.setLayout(cardLayout);
JButton nextButton = new JButton("next");
nextButton.addActionListener(new ActionListener(){
publicvoid actionPerformed(ActionEvent e) {
cardLayout.next(contentPanel);
}});
controlPanel.add(nextButton);
}
|
GridLayout
GridLayout让你建立一个组件表格,并且当组件加入时,会依序又左至右,由上至下填充到每个格子,它不能由你指定想放那个格子就放那个格子
效果:
内容面板代码:
publicstaticvoid addComponentsToPane(Container pane) {
JButton[] buttons = new JButton[9];
pane.setLayout(new GridLayout(3, 3));
for (int i = 0; i < buttons.length; i++) {
buttons[i] = new JButton(i + "");
pane.add(buttons[i]);
}
}
|
GridBagLayout
GridBagLayout是所有AWT布局管理器当中最复杂的,同时他的功能也是最强大的。GridBagLayout同GridLayout一样,在容器中以网格形式来管理组件。但GridBagLayout功能要来得强大得多。
1、GridBagLayout管理的所有行和列都可以是大小不同的;
2、GridLayout把每个组件限制到一个单元格,而GridBagLayout并不这样:组件在容器中可以占据任意大小的矩形区域。
GridBagLayout通常由一个专用类来对他布局行为进行约束,该类叫GridBagConstraints。其中有11个公有成员变量,GridBagConstraints可以从这11个方面来进行控制和操纵。这些内容是:
1、gridx—组件的横向坐标;
2、girdy—组件的纵向坐标;
3、gridwidth—组件的横向宽度,也就是指组件占用的列数;
4、gridheight—组件的纵向长度,也就是指组件占用的行数;
5、weightx—指行的权重,告诉布局管理器如何分配额外的水平空间;
6、weighty—指列的权重,告诉布局管理器如何分配额外的垂直空间;
7、anchor—当组件小于其显示区域时使用此字段;
8、fill—如果显示区域比组件的区域大的时候,可以用来控制组件的行为。控制组件是垂直填充,还是水平填充,或者两个方向一起填充;
9、insets—指组件与表格空间四周边缘的空白区域的大小;
10、ipadx— 组件间的横向间距,组件的宽度就是这个组件的最小宽度加上ipadx值;
11、ipady— 组件间的纵向间距,组件的高度就是这个组件的最小高度加上ipady值。
说明:
1、gridx,gridy:其实就是组件行列的设置,注意都是从0开始的,比如 gridx=0,gridy=1时放在0行1列;
2、gridwidth,gridheight:默认值为1;GridBagConstraints.REMAINDER常量,代表此组件为此行或此列的最后一个组件,会占据所有剩余的空间;
3、weightx,weighty:当窗口变大时,设置各组件跟着变大的比例。比如组件A的weightx=0.5,组件B的weightx=1,那么窗口X轴变大时剩余的空间就会以1:2的比例分配给组件A和B;
4、anchor:当组件空间大于组件本身时,要将组件置于何处。 有CENTER(默认值)、NORTH、NORTHEAST、EAST、SOUTHEAST、WEST、NORTHWEST选择。
5、insets:设置组件之间彼此的间距。它有四个参数,分别是上,左,下,右,默认为(0,0,0,0)。
效果:
内容面板代码:
publicstaticvoid addComponentsToPane(Container pane) {
JButton button;
pane.setLayout(new GridBagLayout());
GridBagConstraints c = new GridBagConstraints();
button = new JButton("Button 1");
c.fill = GridBagConstraints.HORIZONTAL;
c.gridx = 0;
c.gridy = 0;
pane.add(button, c);
button = new JButton("Button 2");
c.fill = GridBagConstraints.HORIZONTAL;
c.weightx = 0.5;
c.gridx = 1;
c.gridy = 0;
pane.add(button, c);
button = new JButton("Button 3");
c.fill = GridBagConstraints.HORIZONTAL;
c.weightx = 0.5;
c.gridx = 2;
c.gridy = 0;
pane.add(button, c);
button = new JButton("Long-Named Button 4");
c.fill = GridBagConstraints.HORIZONTAL;
c.ipady = 40; // make this component tall
c.weightx = 0.0;
c.gridwidth = 3;
c.gridx = 0;
c.gridy = 1;
pane.add(button, c);
button = new JButton("5");
c.fill = GridBagConstraints.HORIZONTAL;
c.ipady = 0; // reset to default
c.weighty = 1.0; // request any extra vertical space
c.anchor = GridBagConstraints.PAGE_END; // bottom of space
c.insets = new Insets(10, 0, 0, 0); // top padding
c.gridx = 1; // aligned with button 2
c.gridwidth = 2; // 2 columns wide
c.gridy = 2; // third row
pane.add(button, c);
}
|
一个GardBagLayout布局的左右选择框,效果:
代码为:
- import java.awt.Dimension;
- import java.awt.GridBagConstraints;
- import java.awt.GridBagLayout;
- import java.awt.event.ActionEvent;
- import java.awt.event.ActionListener;
- import javax.swing.BorderFactory;
- import javax.swing.DefaultListModel;
- import javax.swing.JButton;
- import javax.swing.JFrame;
- import javax.swing.JLabel;
- import javax.swing.JList;
- import javax.swing.JPanel;
- import javax.swing.JTextField;
- public class GridBagLayoutFrame extends JFrame {
- private static final long serialVersionUID = 6819222900970457455L;
- private JPanel mainPanel = new JPanel();
- private JButton addButton = new JButton();
- private JButton leftButton = new JButton();
- private JButton rightButton = new JButton();
- private JLabel label = new JLabel();
- private JTextField field = new JTextField();
- private DefaultListModel leftModel = new DefaultListModel();
- private DefaultListModel rightMOdel = new DefaultListModel();
- private JList leftList = new JList(leftModel);
- private JList rightList = new JList(rightMOdel);
- public GridBagLayoutFrame(String title) {
- setTitle("GridBagLayoutFrameDemo");
- setPreferredSize(new Dimension(600, 400));
- setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
- initComponent();
- addData();
- pack();
- setVisible(true);
- }
- private static void createAndShowGUI() {
- new GridBagLayoutFrame("GridBagLayoutFrameDemo");
- }
- private void initComponent() {
- label.setText("添加选项:");
- addButton.setText("添加");
- leftList.setPreferredSize(new Dimension(150, 150));
- rightList.setPreferredSize(leftList.getPreferredSize());
- leftButton.setText("左");
- rightButton.setText("右");
- mainPanel.setBorder(BorderFactory.createTitledBorder("左右选择框"));
- mainPanel.setLayout(new GridBagLayout());
- GridBagConstraints c = new GridBagConstraints();
- c.gridx = 0; // 0行0列
- c.gridy = 0;
- c.gridwidth = 1;
- c.gridheight = 1;
- c.fill = GridBagConstraints.HORIZONTAL;
- c.weightx = 0;
- c.weighty = 0;
- mainPanel.add(label, c);
- c.gridx++;
- c.weightx = 1;
- mainPanel.add(field, c);
- c.gridx++;
- c.weightx = 0;
- c.gridwidth = 1;
- c.gridheight = 1;
- // c.fill = GridBagConstraints.HORIZONTAL;
- mainPanel.add(addButton, c);
- c.gridx = 0;
- c.gridy = 1;
- c.weightx = 1;
- c.weighty = 1;
- c.gridwidth = 2;
- c.gridheight = 2;
- c.fill = GridBagConstraints.BOTH;
- mainPanel.add(leftList, c);
- c.gridx = 2;
- c.gridy = 1;
- c.gridwidth = 1;
- c.gridheight = 1;
- c.weightx = 0;
- c.weighty = 0.5;
- c.anchor = GridBagConstraints.SOUTH;
- c.fill = GridBagConstraints.HORIZONTAL;
- mainPanel.add(leftButton, c);
- c.gridx = 2;
- c.gridy = 2;
- c.anchor = GridBagConstraints.NORTH;
- c.fill = GridBagConstraints.HORIZONTAL;
- mainPanel.add(rightButton, c);
- c.gridx = 3;
- c.gridy = 1;
- c.gridwidth = 1;
- c.gridheight = 2;
- c.weightx = 1;
- c.weighty = 1;
- c.fill = GridBagConstraints.BOTH;
- mainPanel.add(rightList, c);
- this.getContentPane().add(mainPanel);
- }
- private void addData() {
- addButton.addActionListener(new ActionListener() {
- public void actionPerformed(ActionEvent e) {
- addItem();
- }
- });
- leftButton.addActionListener(new ActionListener() {
- public void actionPerformed(ActionEvent e) {
- leftItem();
- }
- });
- rightButton.addActionListener(new ActionListener() {
- public void actionPerformed(ActionEvent e) {
- rightItem();
- }
- });
- }
- private void addItem() {
- if (field.getText() != null && !field.getText().equals("")) {
- ((DefaultListModel) leftList.getModel())
- .addElement(field.getText());
- field.setText("");
- }
- }
- private void leftItem() {
- if (rightList.getSelectedIndex() != -1) {
- Object o = rightList.getSelectedValue();
- ((DefaultListModel) rightList.getModel()).remove(rightList
- .getSelectedIndex());
- ((DefaultListModel) leftList.getModel()).addElement(o);
- }
- }
- private void rightItem() {
- if (leftList.getSelectedIndex() != -1) {
- Object o = leftList.getSelectedValue();
- ((DefaultListModel) leftList.getModel()).remove(leftList
- .getSelectedIndex());
- ((DefaultListModel) rightList.getModel()).addElement(o);
- }
- }
- public static void main(String[] args) {
- javax.swing.SwingUtilities.invokeLater(new Runnable() {
- public void run() {
- createAndShowGUI();
- }
- });
- }
- }