2013-04-24 33 views
0

我使用这个删除JTable的所有行:删除JTable中的所有行咬了它的足迹依然

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

但删除后,其足迹遗迹!请检查此屏幕截图:
JTable after deletion

这只发生在我删除所有行时,如果连一行都会出现bo问题!
为什么会发生这种情况?我该如何解决它?
感谢

+1

不太明白你的意思 - 但是:因为它改变下模型的脚底层的数据结构(这可能会或不会导致不通知不使用第一线** **过它的听众正确) – kleopatra 2013-04-24 21:58:27

+0

@kleopatra:我的意思是当我删除像这样的行时,UI不会更新!无论如何,我通过在删除后调用myTable.updateUI();来修复它;如果这种方法是错误的,我怎样才能清除'JTable';我认为用'model.removeRow(i)'逐行删除是低效率的;不是吗? – RYN 2013-04-24 22:04:12

+0

当然,它没有更新,模型如何知道你已经从内部结构中删除了所有的数据?你应该使用removeRow来代替 – MadProgrammer 2013-04-24 22:19:53

回答

1

使用DefaultTableModel,你唯一的选择是使用由模型所提供的功能,removeRow

removeRow会火,告诉它需要更新自身JTable需要相应的事件。该表具有这样走了优化,提高了涂装工艺

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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); 
     } 

    } 

} 

如果你真的担心性能,你需要创建自己的模型,并创建自己的clear方法引发适当的事件。

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); 
      } 
     } 
    } 
} 
+0

呃......不,不需要什么在DefaultTableModel中循环:setRowCount(0)是使用的方法。顺便说一句,在自定义模型中,你不会触发dataChanged:如你所知道发生了什么(全部删除),rowsDeleted将是最合适的。 – kleopatra 2013-04-25 07:43:34

+0

1-显示我多久使用'DefaultTableModel' 2-我只是懒惰:P - 更正(这是对的,我很害怕你)) – MadProgrammer 2013-04-25 09:29:54

+1

你已经够远了 kleopatra 2013-04-25 09:40:32