當單元格JComboBox中存在ItemEvent時，如何獲取CellRow

Question

我有一個帶有包含JComboBox的列的JTable。

我有一個ItemListener附加到JComboBox，它對任何更改都起作用。

但是，ItemListener沒有獲取更改後的組合框所在的行的方法。

我需要行號以便在ComboBox發生更改時對同一行中的另一列執行操作。

任何幫助，將不勝感激。

---

這是我的簡短代碼。我試圖完成的是當itemlistener選擇一個變化時獲取ComboBox的表格行。

import java.awt.*; 
import java.awt.event.ItemEvent; 
import java.awt.event.ItemListener; 
import java.io.IOException; 
import javax.swing.*; 
import javax.swing.table.DefaultTableModel; 
import javax.swing.table.TableCellRenderer; 
import javax.swing.table.TableColumn; 

public class Example extends JFrame { 

    private static final long serialVersionUID = 1L; 
    public static int maxX, maxY; 
    public static final String[] columnHeads = {"Col 1", "Col 2", "Col 3"}; 

    public static void main(String args[]) throws IOException { 
     Example example = new Example(); 
    } 

    public Example() { 
     //Create Table Model 
     DefaultTableModel model = new DefaultTableModel(); 

     for (int index = 0; index < columnHeads.length; index++) { 
      model.addColumn(columnHeads[index]); 
     } 

     //Create Table 
     JTable table = new JTable(model); 
     JScrollPane scrollPane = new JScrollPane(table); 

     //List for ComboBox 
     String[] list = {"Item1", "Item2", "Item3"}; 

     //Create ComboBox 
     JComboBox itemTypes = attachComboBoxRenderer(table, 2, list); 

     //Attach Item Listener 
     itemTypes.addItemListener(new ComboBoxListener()); 
     ((DefaultTableModel) table.getModel()).insertRow(
      table.getRowCount(), new Object[]{"C1", "C2", ""}); 
     this.setTitle("Example"); 
     this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
     Container container = getContentPane(); 

     //MAIN Panel 
     final JPanel main = new JPanel(); 
     main.setLayout(new GridBagLayout()); 
     main.add(scrollPane); 

     container.add(main); 
     this.pack(); 
     this.setVisible(true); 
    } 

    public static JComboBox attachComboBoxRenderer(
     JTable table, int column, Object[] values) { 
     JComboBox combo = new JComboBox(values); 
     TableColumn col = table.getColumnModel().getColumn(column); 
     col.setCellRenderer(new ComboBoxRenderer(values)); 
     col.setCellEditor(new DefaultCellEditor(combo)); 
     return combo; 
    } 
} 

class ComboBoxListener implements ItemListener { 

    private static final int SELECTED = 1; 

    @Override 
    public void itemStateChanged(ItemEvent e) { 
     // Get the affected item 
     Object item = e.getItem(); 
     if (item.toString() != null 
      && !"".equals(item.toString()) 
      && e.getStateChange() == SELECTED) { 
      System.out.println(item.toString() + " selected"); 
      //How do I get Row in the Table of the ComboBox that was changed? 
     } 
    } 
} 

class ComboBoxRenderer extends JComboBox implements TableCellRenderer { 

    private static final long serialVersionUID = 1L; 

    public ComboBoxRenderer(Object[] items) { 
     super(items); 
    } 

    @Override 
    public Component getTableCellRendererComponent(JTable table, Object value, 
     boolean isSelected, boolean hasFocus, int row, int column) { 
     if (isSelected) { 
      setForeground(table.getSelectionForeground()); 
      super.setBackground(table.getSelectionBackground()); 
     } else { 
      setForeground(table.getForeground()); 
      setBackground(table.getBackground()); 
     } 
     // Select the current value 
     setSelectedItem(value); 
     return this; 
    } 
} 

Answer 1

聽起來好像你是Using a Combo Box as an Editor。如果是這樣，TableCellEditor方法getTableCellEditorComponent()包括row作爲參數。有一個相關示例here。

附錄：要更改已編輯的同一行中的值，只需根據該行中的相關值爲模型返回「其他列」的正確值。或者，在觸發更新之前更新模型的setValueAt()方法中的相關值，如example所示。

附錄：根據您的示例，下面的代碼將覆蓋模型的getValueAt()方法，以使相關列與項目列保持同步。

import java.awt.*; 
import java.awt.event.ItemEvent; 
import java.awt.event.ItemListener; 
import java.io.IOException; 
import javax.swing.*; 
import javax.swing.table.DefaultTableModel; 
import javax.swing.table.TableColumn; 

/** @see http://stackoverflow.com/questions/7350445 */ 
public class DependentColumn extends JFrame { 

    private static final int DEPENDENT_COL = 1; 
    private static final int ITEM_COL = 2; 
    private static final String[] columnNames = {"Col 1", "Col 2", "Col 3"}; 

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

      @Override 
      public void run() { 
       DependentColumn dc = new DependentColumn(); 
      } 
     }); 
    } 

    public DependentColumn() { 
     this.setTitle("Example"); 
     this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 

     //Create Model & Table 
     DefaultTableModel model = new DefaultTableModel(columnNames, 0) { 

      @Override 
      public Object getValueAt(int row, int col) { 
       if (col == DEPENDENT_COL) { 
        return "C2:" + this.getValueAt(row, ITEM_COL); 
       } else { 
        return super.getValueAt(row, col); 
       } 
      } 
     }; 
     for (int i = 0; i < 16; i++) { 
      model.addRow(new Object[]{"C1", "C2", "Item1"}); 
     } 
     JTable table = new JTable(model); 
     table.setPreferredScrollableViewportSize(new Dimension(320, 120)); 

     //Create ComboBox 
     String[] items = {"Item1", "Item2", "Item3"}; 
     JComboBox combo = new JComboBox(items); 
     TableColumn col = table.getColumnModel().getColumn(ITEM_COL); 
     col.setCellEditor(new DefaultCellEditor(combo)); 
     combo.addItemListener(new ItemListener() { 

      @Override 
      public void itemStateChanged(ItemEvent e) { 
       if (e.getStateChange() == ItemEvent.SELECTED) { 
        System.out.println(e.getItem() + " selected"); 
       } 
      } 
     }); 

     this.add(new JScrollPane(table)); 
     this.pack(); 
     this.setLocationRelativeTo(null); 
     this.setVisible(true); 
    } 
}