刪除JTable中的所有行咬了它的足跡依然

Question

我使用這個刪除JTable的所有行：

myTableModel.getDataVector().removeAllElements(); 
myTableModel.setRowCount(0); 

但刪除後，其足跡遺蹟！請檢查此屏幕截圖：

這隻發生在我刪除所有行時，如果連一行都會出現bo問題！
爲什麼會發生這種情況？我該如何解決它？
感謝

Answer 1

使用DefaultTableModel，你唯一的選擇是使用由模型所提供的功能，removeRow

removeRow會火，告訴它需要更新自身JTable需要相應的事件。該表具有這樣走了優化，提高了塗裝工藝

import java.awt.BorderLayout; 
import java.awt.EventQueue; 
import java.awt.event.ActionEvent; 
import javax.swing.AbstractAction; 
import javax.swing.JButton; 
import javax.swing.JFrame; 
import javax.swing.JScrollPane; 
import javax.swing.JTable; 
import javax.swing.UIManager; 
import javax.swing.UnsupportedLookAndFeelException; 
import javax.swing.table.DefaultTableModel; 
import javax.swing.table.TableModel; 

public class TestTable { 

    public static void main(String[] args) { 
     new TestTable(); 
    } 

    public TestTable() { 
     EventQueue.invokeLater(new Runnable() { 
      @Override 
      public void run() { 
       try { 
        UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName()); 
       } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) { 
       } 

       DefaultTableModel model = new DefaultTableModel(); 
       JTable table = new JTable(model); 
       for (int index = 0; index < 10; index++) { 
        model.addColumn(index); 
       } 
       for (int row = 0; row < 1000; row++) { 
        String[] values = new String[10]; 
        for (int col = 0; col < 10; col++) { 
         values[col] = row + "x" + col; 
        } 
        model.addRow(values); 
       } 

       JFrame frame = new JFrame("Test"); 
       frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
       frame.setLayout(new BorderLayout()); 
       frame.add(new JScrollPane(table)); 
       frame.add(new JButton(new DeleteRowsFromDefaultModel(model)), BorderLayout.SOUTH); 
       frame.pack(); 
       frame.setLocationRelativeTo(null); 
       frame.setVisible(true); 
      } 

     }); 
    } 

    public class DeleteRowsFromDefaultModel extends AbstractAction { 

     private final DefaultTableModel model; 

     public DeleteRowsFromDefaultModel(DefaultTableModel model) { 
      this.model = model; 
      putValue(NAME, "Delete All"); 
     } 

     @Override 
     public void actionPerformed(ActionEvent e) { 
      model.setRowCount(0); 
     } 

    } 

} 

如果你真的擔心性能，你需要創建自己的模型，並創建自己的clear方法引發適當的事件。

import java.awt.BorderLayout; 
import java.awt.EventQueue; 
import java.awt.event.ActionEvent; 
import java.util.ArrayList; 
import java.util.List; 
import javax.swing.AbstractAction; 
import javax.swing.JButton; 
import javax.swing.JFrame; 
import javax.swing.JScrollPane; 
import javax.swing.JTable; 
import javax.swing.UIManager; 
import javax.swing.UnsupportedLookAndFeelException; 
import javax.swing.table.AbstractTableModel; 
import javax.swing.table.DefaultTableModel; 

public class TestTable1 { 

    public static void main(String[] args) { 
     new TestTable1(); 
    } 

    public TestTable1() { 
     EventQueue.invokeLater(new Runnable() { 
      @Override 
      public void run() { 
       try { 
        UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName()); 
       } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) { 
       } 

       MyTabelModel model = new MyTabelModel(); 
       JTable table = new JTable(model); 

       JFrame frame = new JFrame("Test"); 
       frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
       frame.setLayout(new BorderLayout()); 
       frame.add(new JScrollPane(table)); 
       frame.add(new JButton(new DeleteRowsFromMyModel(model)), BorderLayout.SOUTH); 
       frame.pack(); 
       frame.setLocationRelativeTo(null); 
       frame.setVisible(true); 
      } 
     }); 
    } 

    public class DeleteRowsFromMyModel extends AbstractAction { 

     private final MyTabelModel model; 

     public DeleteRowsFromMyModel(MyTabelModel model) { 
      this.model = model; 
      putValue(NAME, "Delete All"); 
     } 

     @Override 
     public void actionPerformed(ActionEvent e) { 
      model.clear(); 
     } 
    } 

    public class MyTabelModel extends AbstractTableModel { 

     private List<String[]> rows; 

     public MyTabelModel() { 
      rows = new ArrayList<>(1000); 
      for (int row = 0; row < 1000; row++) { 
       String[] values = new String[10]; 
       for (int col = 0; col < 10; col++) { 
        values[col] = row + "x" + col; 
       } 
       rows.add(values); 
      } 
     } 

     @Override 
     public int getRowCount() { 
      return rows.size(); 
     } 

     @Override 
     public int getColumnCount() { 
      return 10; 
     } 

     @Override 
     public String getColumnName(int column) { 
      return String.valueOf(column); 
     } 

     @Override 
     public Object getValueAt(int rowIndex, int columnIndex) { 
      String[] row = rows.get(rowIndex); 
      return row[columnIndex]; 
     } 

     public void clear() { 
      int old = getRowCount(); 
      if (old > 0) { 
       rows.clear(); 
       fireTableRowsDeleted(0, old - 1); 
      } 
     } 
    } 
}