Question

我有一个JTable的子类，它使用自定义表模型（AbstractTableModel的实现）来管理数据。

当我尝试使用方法deleteRow删除行时，会出现问题。我的表中的行被空字符串替换，但该行不会被删除。

以下是代码：

public class LiveSearchTableModel extends AbstractTableModel 
{

  private List<String> columnNames = new ArrayList<String>();
  private Map<Point, Object> displayData = new HashMap<Point, Object>();
  private Map<Point, Object> originalData = new HashMap<Point, Object>();

  public LiveSearchTableModel(List<String> columnNames, 
      Map<Point, Object> tableData) 
  {
    this.columnNames = columnNames;
    this.displayData = tableData;
    this.originalData.putAll(tableData); 
  }

  @Override
  public int getColumnCount() {
    return columnNames.size();
  }

  @Override
  public int getRowCount() {
    return displayData.size() / columnNames.size();
  }

  @Override
  public Object getValueAt(int rowIndex, int columnIndex) {
    return displayData.get(new Point(rowIndex, columnIndex));
  }

  public void deleteRow (int row)
  {
    for (int cont = 0; cont < columnNames.size();cont++)
    {   
      displayData.remove(new Point (row,cont)); 
    }

    this.fireTableRowsDeleted(row, row);
  }

  @Override
  public void setValueAt(Object value, int rowIndex, int columnIndex) 
  {
    this.displayData.put(new Point(rowIndex, columnIndex), value);
    this.fireTableDataChanged();
  }
}

Answer 1

下面的sscce说明了一个潜在的问题：Map的键没有排序，而表的行是。在所示的方法中，必须通过每次更改数据来更新密钥数组。另请参阅此相关example。如果需要，您可以延长Point以实施Comparable，如Value所示here。

import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.awt.Point;
import java.awt.event.ActionEvent;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import javax.swing.AbstractAction;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.table.AbstractTableModel;

/**
* @see https://stackoverflow.com/q/12330167/230513
*/
public class TableModelTest extends JPanel {

    public TableModelTest() {
        super(new BorderLayout());
        final MyModel model = new MyModel();
        JTable table = new JTable(model);
        this.add(new JScrollPane(table));
        this.add(new JButton(new AbstractAction("Delete") {

            @Override
            public void actionPerformed(ActionEvent e) {
                model.remove(0);
            }
        }), BorderLayout.SOUTH);
    }

    public class MyModel extends AbstractTableModel {

        private List<String> names = new ArrayList<String>();
        private Map<Point, Object> data = new HashMap<Point, Object>();
        private Point[] keys;

        public MyModel() {
            this.names = Arrays.asList("Point", "Name");
            data.put(new Point(1, 1), "One");
            data.put(new Point(2, 2), "Two");
            data.put(new Point(3, 3), "Three");
            this.keys = data.keySet().toArray(new Point[data.size()]);
        }

        public void remove(int row) {
            data.remove(keys[row]);
            keys = data.keySet().toArray(new Point[data.size()]);
            this.fireTableRowsDeleted(row, row);
        }

        @Override
        public int getColumnCount() {
            return names.size();
        }

        @Override
        public String getColumnName(int col) {
            return names.get(col);
        }

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

        @Override
        public Object getValueAt(int row, int col) {
            if (col == 0) {
                return keys[row];
            } else {
                return data.get(keys[row]);
            }
        }
    }

    private void display() {
        JFrame f = new JFrame("TableModelTest");
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.add(this);
        f.pack();
        f.setLocationRelativeTo(null);
        f.setVisible(true);
    }

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {

            @Override
            public void run() {
                new TableModelTest().display();
            }
        });
    }
}

使用自定义表模型从JTable中删除行

1 个答案: