JTable dynamisch Zeilen hinzufügen und entfernen: Unterschied zwischen den Versionen
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− | + | <span style="font-size:9px; color:aaa;">(Basierend auf einem Codebeispiel von Marco13)</span> |
Version vom 27. Mai 2014, 11:22 Uhr
Mit folgendem Code kann man, ähnlich wie in Excel Zeilen dynamisch beim Scrollen in die JTable einfügen oder auch leere, nicht benutzte Zeilen wieder löschen.
<code=java> import java.awt.*; import java.awt.event.*;
import javax.swing.*; import javax.swing.table.*;
public class DynamicRows extends JFrame implements AdjustmentListener {
private JScrollPane jScrollPane1; private JTable jTable1; private DefaultTableModel model; private int yVisible, yVisibleOld; private boolean valueIsAdjusting = false;
public DynamicRows() { super("DynamicRows"); setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE); setSize(400, 300); setLocationRelativeTo(null); jScrollPane1 = new JScrollPane(); jTable1 = new JTable(); jTable1.setModel(new DefaultTableModel( new Object[][]{}, new String[]{ "Title 1", "Title 2", "Title 3", "Title 4" })); jScrollPane1.setViewportView(jTable1); getContentPane().add(jScrollPane1, BorderLayout.CENTER); model = (DefaultTableModel) jTable1.getModel(); for (int i = 0; i < 20; i++) { model.addRow(new Object[]{null, null, null, null});
}
jScrollPane1.getVerticalScrollBar().addAdjustmentListener(this); }
public void adjustmentValueChanged(final AdjustmentEvent e) { if (e.getValueIsAdjusting()) { valueIsAdjusting = true; return; } Adjustable a = e.getAdjustable(); Rectangle rectBottom = jTable1.getCellRect(model.getRowCount() - 1, 0, true); int yBottom = rectBottom.y + rectBottom.height; Rectangle rectVisible = jTable1.getVisibleRect(); yVisible = rectVisible.y + rectVisible.height; //if we are scrolling upwards: if (yVisible != 0 && yVisible < yVisibleOld) { //remove all invisible rows if they area empty (from bottom to top): boolean remove = true; for (int row = jTable1.getRowCount() - 1; row > -1; row--) { if (jTable1.getCellRect(row, 0, true).y > yVisible) {//if row is invisible for (int column = 0; column < jTable1.getColumnCount(); column++) { Object value = jTable1.getValueAt(row, column); if (value != null) {//if the row is not empty remove = false;//do not remove any more rows } } if (remove) { model.removeRow(row); } } } } else {
//here we are scrolling downwards
//if visible area is at bottom: if ((yBottom == yVisible)) { if (valueIsAdjusting) { valueIsAdjusting = false; rectVisible.y = rectVisible.y - 2; yVisible = yVisible - 2; jTable1.scrollRectToVisible(rectVisible); } else { a.removeAdjustmentListener(this); //add new row and scroll to visible: model.addRow(new Object[]{null, null, null, null}); rectBottom = jTable1.getCellRect(model.getRowCount() - 1, 0, true); rectBottom.height = rectBottom.height - 1; jTable1.scrollRectToVisible(rectBottom); a.addAdjustmentListener(this); } } } yVisibleOld = yVisible;
}
public static void main(final String args[]) { EventQueue.invokeLater(new Runnable() { public void run() { new DynamicRows().setVisible(true); } }); }
} </code=java>
(Basierend auf einem Codebeispiel von Marco13)