滾動條未創建/表未顯示

Question

我正在編寫一個程序，其中有一個可創建的JTable（我可以）。但我想添加一個滾動條。以下是我的代碼。

import java.awt.event.ActionEvent; 
import java.awt.event.ActionListener; 
import java.util.concurrent.Executor; 
import java.util.concurrent.Executors; 

import javax.swing.JButton; 
import javax.swing.JFileChooser; 
import javax.swing.JFrame; 
import javax.swing.JPanel; 
import javax.swing.JScrollPane; 
import javax.swing.JTable; 
import javax.swing.JTextField; 
import javax.swing.SwingUtilities; 
import javax.swing.border.EmptyBorder; 
import javax.swing.table.DefaultTableModel; 

public class TagReplaceUI extends JFrame { 

    private JPanel contentPane; 
    private JTextField srcTextField; 
    private Executor executor = Executors.newCachedThreadPool(); 
    static DefaultTableModel model = new DefaultTableModel(); 
    static JTable table = new JTable(model); 

    /** 
    * Launch the application. 
    */ 
    public static void main(String[] args) { 
     SwingUtilities.invokeLater(new Runnable() { 
      @Override 
      public void run() { 
       try { 
        final TagReplaceUI frame = new TagReplaceUI(); 
        frame.add(new JScrollPane(table)); 
        frame.setVisible(true); 
       } catch (Exception e) { 
        e.printStackTrace(); 
       } 
      } 
     }); 
    } 

    /** 
    * Create the frame. 
    */ 
    // FileDownloadTest downloadTest = new 
    // FileDownloadTest(srcTextField.getText(), textArea); 

    public TagReplaceUI() { 
     setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
     setBounds(100, 100, 552, 358); 
     contentPane = new JPanel(); 
     contentPane.setBorder(new EmptyBorder(5, 5, 5, 5)); 
     setContentPane(contentPane); 
     contentPane.setLayout(null); 

     srcTextField = new JTextField(); 
     srcTextField.setBounds(10, 26, 399, 20); 
     contentPane.add(srcTextField); 
     srcTextField.setColumns(10); 

     JButton srcBtn = new JButton("Source Excel"); 
     srcBtn.addActionListener(new ActionListener() { 
      public void actionPerformed(ActionEvent e) { 
       JFileChooser fChoose = new JFileChooser(); 
       fChoose.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY); 
       if (fChoose.showOpenDialog(null) == JFileChooser.APPROVE_OPTION) { 
        srcTextField.setText(fChoose.getSelectedFile().getAbsolutePath()); 
       } else { 
        System.out.println("No Selection"); 
       } 
      } 
     }); 

     table.setBounds(10, 131, 516, 178); 
     contentPane.add(table); 
     model.addColumn("Col1"); 
     model.addColumn("Col2"); 

     srcBtn.setBounds(419, 25, 107, 23); 
     contentPane.add(srcBtn); 

     JButton dNcButton = new JButton("Process"); 
     dNcButton.addActionListener(new ActionListener() { 
      public void actionPerformed(ActionEvent arg0) { 
       executor.execute(new Test(srcTextField.getText(), model)); 
      } 
     }); 
     dNcButton.setBounds(212, 70, 89, 23); 
     contentPane.add(dNcButton); 

    } 

} 

當我運行上述程序時，表格框架也不會顯示。但是，當我刪除frame.add(new JScrollPane(table));時，它將在JTable區域中顯示錶格，但其中沒有滾動條。

請讓我知道如何在表格中獲得滾動條並正確顯示數據。

感謝

Answer 1

起初不使用空佈局，請閱讀here。

frame.add(new JScrollPane(table));此滾動窗格不顯示，因爲在空佈局中，每個組件都需要有邊界。嘗試下面的代碼。我只是將靜態變量更改爲實例變量。並將scrollpane添加到構造函數中。

import java.awt.event.ActionEvent; 
import java.awt.event.ActionListener; 
import java.util.concurrent.Executor; 
import java.util.concurrent.Executors; 

import javax.swing.JButton; 
import javax.swing.JFileChooser; 
import javax.swing.JFrame; 
import javax.swing.JPanel; 
import javax.swing.JScrollPane; 
import javax.swing.JTable; 
import javax.swing.JTextField; 
import javax.swing.SwingUtilities; 
import javax.swing.border.EmptyBorder; 
import javax.swing.table.DefaultTableModel; 

public class TagReplaceUI extends JFrame { 

    private JPanel contentPane; 
    private JTextField srcTextField; 
    private Executor executor = Executors.newCachedThreadPool(); 
    private DefaultTableModel model = new DefaultTableModel(); 
    private JTable table = new JTable(model); 

    /** 
    * Launch the application. 
    */ 
    public static void main(String[] args) { 
     SwingUtilities.invokeLater(new Runnable() { 
      @Override 
      public void run() { 
       try { 
        final TagReplaceUI frame = new TagReplaceUI(); 

        frame.setVisible(true); 
       } catch (Exception e) { 
        e.printStackTrace(); 
       } 
      } 
     }); 
    } 

    /** 
    * Create the frame. 
    */ 
    // FileDownloadTest downloadTest = new 
    // FileDownloadTest(srcTextField.getText(), textArea); 

    public TagReplaceUI() { 
     setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
     setBounds(100, 100, 552, 358); 
     contentPane = new JPanel(); 
     contentPane.setBorder(new EmptyBorder(5, 5, 5, 5)); 
     setContentPane(contentPane); 
     contentPane.setLayout(null); 

     srcTextField = new JTextField(); 
     srcTextField.setBounds(10, 26, 399, 20); 
     contentPane.add(srcTextField); 
     srcTextField.setColumns(10); 

     JButton srcBtn = new JButton("Source Excel"); 
     srcBtn.addActionListener(new ActionListener() { 
      public void actionPerformed(ActionEvent e) { 
       JFileChooser fChoose = new JFileChooser(); 
       fChoose.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY); 
       if (fChoose.showOpenDialog(null) == JFileChooser.APPROVE_OPTION) { 
        srcTextField.setText(fChoose.getSelectedFile().getAbsolutePath()); 
       } else { 
        System.out.println("No Selection"); 
       } 
      } 
     }); 

     JScrollPane scroll = new JScrollPane(table); 
     scroll.setBounds(10, 131, 516, 178); 
     contentPane.add(scroll); 
     model.addColumn("Col1"); 
     model.addColumn("Col2"); 

     srcBtn.setBounds(419, 25, 107, 23); 
     contentPane.add(srcBtn); 

     JButton dNcButton = new JButton("Process"); 
     dNcButton.addActionListener(new ActionListener() { 
      public void actionPerformed(ActionEvent arg0) { 
       executor.execute(new Test(srcTextField.getText(), model)); 
      } 
     }); 
     dNcButton.setBounds(212, 70, 89, 23); 
     contentPane.add(dNcButton); 

    } 

}