Question

我是java新手我使用netbean创建java应用程序..i创建了javatable（tb1是变量名）..我已经添加了2行和2列..我有1个按钮..我想做的就是当我点击一个按钮更改表的第一列的背景颜色..工作..但问题是更改颜色我必须点击表..然后我点击表背景颜色的任何地方..不知道是什么问题..这是我的代码任何帮助??

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
package javaapplication57;

import java.awt.Color;
import java.awt.Component;
import javax.swing.JTable;
import javax.swing.table.DefaultTableCellRenderer;
import javax.swing.table.DefaultTableModel;
import javax.swing.table.TableColumn;

/**
 *
 * @author Madhawa
 */
public class NewJFrame extends javax.swing.JFrame {

    /**
     * Creates new form NewJFrame
     */
    public NewJFrame() {
        initComponents();
    }

    /**
     * This method is called from within the constructor to initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is always
     * regenerated by the Form Editor.
     */
    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">                          
    private void initComponents() {

        jButton1 = new javax.swing.JButton();
        jScrollPane1 = new javax.swing.JScrollPane();
        tb1 = new javax.swing.JTable();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

        jButton1.setText("colorize");
        jButton1.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jButton1ActionPerformed(evt);
            }
        });

        tb1.setModel(new javax.swing.table.DefaultTableModel(
            new Object [][] {
                {"madhawa", "123"},
                {"sonic", "234"}
            },
            new String [] {
                "name", "password"
            }
        ) {
            Class[] types = new Class [] {
                java.lang.String.class, java.lang.String.class
            };

            public Class getColumnClass(int columnIndex) {
                return types [columnIndex];
            }
        });
        jScrollPane1.setViewportView(tb1);

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addGap(18, 18, 18)
                .addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 403, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addContainerGap(18, Short.MAX_VALUE))
            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                .addComponent(jButton1, javax.swing.GroupLayout.PREFERRED_SIZE, 215, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addGap(108, 108, 108))
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                .addGap(25, 25, 25)
                .addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 107, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addGap(18, 18, 18)
                .addComponent(jButton1)
                .addContainerGap(37, Short.MAX_VALUE))
        );

        pack();
    }// </editor-fold>                        

    private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {                                         
        // TODO add your handling code here:
        TableColumn col = tb1.getColumnModel().getColumn(0);
DefaultTableModel model3 = (DefaultTableModel)tb1.getModel();
col.setCellRenderer(new CustomRenderer());
    }                                        

    /**
     * @param args the command line arguments
     */
    public static void main(String args[]) {
        /* Set the Nimbus look and feel */
        //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
        /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
         * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html 
         */
        try {
            for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
                if ("Nimbus".equals(info.getName())) {
                    javax.swing.UIManager.setLookAndFeel(info.getClassName());
                    break;
                }
            }
        } catch (ClassNotFoundException ex) {
            java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (javax.swing.UnsupportedLookAndFeelException ex) {
            java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        }
        //</editor-fold>

        /* Create and display the form */
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                new NewJFrame().setVisible(true);
            }
        });
    }
    // Variables declaration - do not modify                     
    private javax.swing.JButton jButton1;
    private javax.swing.JScrollPane jScrollPane1;
    private javax.swing.JTable tb1;
    // End of variables declaration                   
}
class CustomRenderer extends DefaultTableCellRenderer 
{
    public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected, boolean hasFocus, int row, int column)
    {
        Component c = super.getTableCellRendererComponent(table, value, isSelected, hasFocus, row, column);
        setForeground(Color.red); 
        setBackground(Color.YELLOW);
        return c;
    }
}

Answer 1

基本上，表格不知道有什么变化，所以它没有更新。尝试在按钮repaint方法的末尾添加actionPerformed请求，例如......

private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
    // TODO add your handling code here:
    TableColumn col = tb1.getColumnModel().getColumn(0);
    DefaultTableModel model3 = (DefaultTableModel) tb1.getModel();
    col.setCellRenderer(new CustomRenderer());
    tb1.repaint();
}

java jTable CustomRenderer背景颜色只有在我点击它时才会改变..为什么会发生这种情况

1 个答案: