问题
I am trying to build a register, so that when a button is clicked, a new entry appears on a table. Ideally, I am looking to build a table on the left side of the screen, with two rows and new column appears when the button is clicked. I want the table to have a fixed size, but it should be scrollable after a certain amount of entries. So far, I have created and formatted the JButton objects that I want to be clicked for a new entry to appear. I also know that I should use a JTable to pursue this.
How should I go about making this dynamic table?
Code So Far:
private void addRegister(JPanel pane) {
JPanel everythingPane = new JPanel();
JPanel pluPane = new JPanel();
Dimension button = new Dimension(200,150);
JTable pluTable = new JTable();
JPanel buttonPane = new JPanel();
buttonPane.setLayout(new BoxLayout(buttonPane, BoxLayout.Y_AXIS));
//JPanel buttonPane = new JPanel (new FlowLayout (FlowLayout.LEFT));
JPanel subPane1 = new JPanel();
subPane1.setAlignmentX(LEFT_ALIGNMENT);
JPanel subPane2 = new JPanel();
subPane2.setAlignmentX(LEFT_ALIGNMENT);
JPanel subPane3 = new JPanel();
subPane3.setAlignmentX(LEFT_ALIGNMENT);
JPanel subPane4 = new JPanel();
subPane4.setAlignmentX(LEFT_ALIGNMENT);
JPanel subPane5 = new JPanel();
subPane5.setAlignmentX(LEFT_ALIGNMENT);
JPanel alignmentLayer = new JPanel();
JButton frappuccino = new JButton(\"Frappuccino\");
JButton icedCoffee = new JButton(\"Iced Coffee\");
frappuccino.setPreferredSize(button);
icedCoffee.setPreferredSize(button);
JButton arizona = new JButton(\"Arizona Green Tea\");
JButton izze = new JButton(\"Izze\");
arizona.setPreferredSize(button);
izze.setPreferredSize(button);
JButton snapple = new JButton(\"Snapple\");
JButton gatorade = new JButton(\"Gatorade\");
snapple.setPreferredSize(button);
gatorade.setPreferredSize(button);
JButton water = new JButton(\"Water\");
JButton appleJuice = new JButton(\"Apple Juice\");
water.setPreferredSize(button);
appleJuice.setPreferredSize(button);
JButton orangeJuice = new JButton(\"Orange Juice\");
JButton mentos = new JButton(\"Mentos\");
orangeJuice.setPreferredSize(button);
mentos.setPreferredSize(button);
JButton gum = new JButton(\"Gum\");
JButton cliffBar = new JButton(\"Cliff Bar\");
gum.setPreferredSize(button);
cliffBar.setPreferredSize(button);
JButton littleBites = new JButton(\"Little Bites\");
JButton welchs = new JButton(\"Welch\'s Fruit Snacks\");
littleBites.setPreferredSize(button);
welchs.setPreferredSize(button);
JButton fiberOneBar = new JButton(\"Fiber One Bar\");
JButton fiberOneBrownie = new JButton(\"Fiber One Brownie\");
fiberOneBar.setPreferredSize(button);
fiberOneBrownie.setPreferredSize(button);
JButton cheezeIts = new JButton(\"Cheeze Its\");
JButton goldFish = new JButton(\"Gold Fish\");
cheezeIts.setPreferredSize(button);
goldFish.setPreferredSize(button);
JButton teaBag = new JButton(\"Tea Bag\");
JButton poptarts = new JButton(\"Poptarts\");
teaBag.setPreferredSize(button);
poptarts.setPreferredSize(button);
JButton sampleButton = new JButton(\"Sample Button\");
JButton sampleButton2 = new JButton(\"Sample Button\");
sampleButton.setPreferredSize(button);
sampleButton2.setPreferredSize(button);
JButton sampleButton3 = new JButton(\"Sample Button\");
JButton sampleButton4 = new JButton(\"Sample Button\");
sampleButton3.setPreferredSize(button);
sampleButton4.setPreferredSize(button);
subPane1.add(frappuccino);
subPane1.add(icedCoffee);
subPane1.add(arizona);
subPane1.add(izze);
subPane2.add(snapple);
subPane2.add(gatorade);
subPane2.add(water);
subPane2.add(appleJuice);
subPane3.add(orangeJuice);
subPane3.add(mentos);
subPane3.add(gum);
subPane3.add(cliffBar);
subPane4.add(littleBites);
subPane4.add(welchs);
subPane4.add(fiberOneBar);
subPane4.add(fiberOneBrownie);
subPane5.add(cheezeIts);
subPane5.add(goldFish);
subPane5.add(teaBag);
subPane5.add(poptarts);
alignmentLayer.add(sampleButton);
alignmentLayer.add(sampleButton2);
alignmentLayer.add(sampleButton3);
alignmentLayer.add(sampleButton4);
buttonPane.add(subPane1);
buttonPane.add(subPane2);
buttonPane.add(subPane3);
buttonPane.add(subPane4);
buttonPane.add(subPane5);
buttonPane.add(Box.createRigidArea(new Dimension(5,100)));
buttonPane.add(alignmentLayer);
pluPane.add(pluTable);
everythingPane.add(pluPane);
everythingPane.add(buttonPane);
pane.add(everythingPane);
}
回答1:
JTable is more commonly used in a way that adds rows, rather than columns. I re-factored this example to illustrate the basic idea below. Each time the button is clicked, a new row is added to the table's model, which updates the table itself.
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Rectangle;
import java.awt.event.ActionEvent;
import java.awt.event.AdjustmentEvent;
import java.awt.event.AdjustmentListener;
import javax.swing.AbstractAction;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollBar;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.table.DefaultTableModel;
/**
* @see https://stackoverflow.com/a/19472190/230513
* @see https://stackoverflow.com/a/7519403/230513
*/
public class TableAddTest extends JPanel {
private static final int N_ROWS = 8;
private static String[] header = {"ID", "String", "Number", "Boolean"};
private DefaultTableModel dtm = new DefaultTableModel(null, header) {
@Override
public Class<?> getColumnClass(int col) {
return getValueAt(0, col).getClass();
}
};
private JTable table = new JTable(dtm);
private JScrollPane scrollPane = new JScrollPane(table);
private JScrollBar vScroll = scrollPane.getVerticalScrollBar();
private int row;
private boolean isAutoScroll;
public TableAddTest() {
this.setLayout(new BorderLayout());
Dimension d = new Dimension(320, N_ROWS * table.getRowHeight());
table.setPreferredScrollableViewportSize(d);
for (int i = 0; i < N_ROWS; i++) {
addRow();
}
scrollPane.setVerticalScrollBarPolicy(
JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
vScroll.addAdjustmentListener(new AdjustmentListener() {
@Override
public void adjustmentValueChanged(AdjustmentEvent e) {
isAutoScroll = !e.getValueIsAdjusting();
}
});
this.add(scrollPane, BorderLayout.CENTER);
JPanel panel = new JPanel();
panel.add(new JButton(new AbstractAction("Add Row") {
@Override
public void actionPerformed(ActionEvent e) {
addRow();
}
}));
this.add(panel, BorderLayout.SOUTH);
}
private void addRow() {
char c = (char) ('A' + row++ % 26);
dtm.addRow(new Object[]{
Character.valueOf(c),
String.valueOf(c) + String.valueOf(row),
Integer.valueOf(row),
Boolean.valueOf(row % 2 == 0)
});
}
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
JFrame f = new JFrame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
TableAddTest nlt = new TableAddTest();
f.add(nlt);
f.pack();
f.setLocationRelativeTo(null);
f.setVisible(true);
}
});
}
}
来源：https://stackoverflow.com/questions/19471404/create-dynamic-table-to-add-new-entry-with-button