调整 JTable 大小

Question

I have a JTable with user data distributed in rows and columns . I want when, I look for a user using the ID in a JTextField , resize the size ( height , with the same width ) depending on the number of rows found. Why is the width of the table reduced?

Code:

    tabla_clientes.setPreferredScrollableViewportSize(
            new Dimension(tabla_clientes.getPreferredSize().width, tabla_clientes.getRowHeight()*20)
    );

    //...

private void resizer() {
    revalidate();
    int w = jScrollPane.getPreferredSize().width; //width scroll pane
    int h1 = jScrollPane.getViewport().getViewSize().height; //height viewport
    int h2 = tabla_clientes.getPreferredScrollableViewportSize().height; //table height

    if(h1<h2)
      jScrollPane.setSize(new Dimension(w,h1));
    else
      jScrollPane.setSize(tabla_clientes.getPreferredScrollableViewportSize());
}

public void filtrar_dni() {
    int columna = 0;
    TRSFiltro.setRowFilter(RowFilter.regexFilter(textfield_buscar.getText(), columna));
}


private void textfield_buscarKeyTyped(java.awt.event.KeyEvent evt) {                                          
    textfield_buscar.addKeyListener(new KeyAdapter(){
    public void keyReleased(final KeyEvent e){
        String texto = (textfield_buscar.getText());
        textfield_buscar.setText(texto);
        filtrar_dni();
        resizer();
    }
    });
    
    TRSFiltro = new TableRowSorter<DefaultTableModel>((DefaultTableModel) tabla_clientes.getModel());
    tabla_clientes.setRowSorter(TRSFiltro);
}

Unexpected result:

Original table:

Answer 1

You should use LayoutManagers: https://docs.oracle.com/javase/tutorial/uiswing/layout/visual.html This makes positioning of the components much easier. An easy to understand example could be:

import javax.swing.*;
import java.awt.*;

public class Test {

    public static void main(String[] args) {
        JLabel bigLabel = new JLabel("VERY BIG");
        bigLabel.setPreferredSize(new Dimension(100, 1000));

        JPanel north = new JPanel();
        north.setLayout(new FlowLayout());
        north.add(new JLabel("NORTH CONTENT"));

        JScrollPane p = new JScrollPane();
        p.setViewportView(bigLabel);

        JFrame f = new JFrame();
        f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
        f.setPreferredSize(new Dimension(200, 300));
        f.getContentPane().setLayout(new BorderLayout());
        f.getContentPane().add(north, BorderLayout.NORTH);
        f.getContentPane().add(p, BorderLayout.CENTER);
        f.pack();
        f.setLocationRelativeTo(null);
        f.setVisible(true);
    }
}

I'm not going to show you the version without layout managers, because 1) I'm not even sure to be able to write it correctly and 2) you should not do it anyway, except when you have a very good reason to (eg. no Layout Manager exist for your needs - which is, btw, very rare).