java - jtable中的动态jcombobox项目

Question

我正在尝试创建一个每行有两个组合框的 Jtable。我检查了这方面的教程，发现我可以在组合框中添加静态数据。但是我怎么可以将动态数据加载到组合框中。

甚至，每当用户从行中选择组合框 1 时，都会基于此更新组合框 2。

有人可以帮我吗？

如果我removeAllItems()从组合框中进行操作，那么组合框 2 将更新，但我无法添加新条目。

提前致谢。

Answer 1

表有两列都呈现为JComboBox.现在，Column-2 项目的选择取决于 Column-1 选择。

import java.awt.Component;
import java.awt.EventQueue;
import java.util.ArrayList;
import java.util.List;

import javax.swing.DefaultCellEditor;
import javax.swing.DefaultComboBoxModel;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTable;


public class ComboBoxExample {

    private void createUI() {

        JFrame frame = new JFrame();

        Object[] columNames = {"Combo-1", "Combo-2"};
        Object[][] data = {{"", ""}, {"", ""}, {"", ""}, {"", ""}};

        JTable table = new JTable(data, columNames);

        table.getColumnModel().getColumn(0).setCellEditor(new CustomComboBoxEditor());
        table.getColumnModel().getColumn(1).setCellEditor(new CustomComboBoxEditor());

        frame.add(new JScrollPane(table));
        frame.setTitle("Column -2 based on Column - 1 ComboBox Selection.");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.pack();
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        Runnable r = new Runnable() {

            @Override
            public void run() {
                new ComboBoxExample().createUI();
            }
        };

        EventQueue.invokeLater(r);
    }

}

class CustomComboBoxEditor extends DefaultCellEditor {

    // Declare a model that is used for adding the elements to the `ComboBox`
    private DefaultComboBoxModel model;

    private List<String> obtainedList;

    public CustomComboBoxEditor() {
        super(new JComboBox());
        this.model = (DefaultComboBoxModel)((JComboBox)getComponent()).getModel();
        obtainedList = new ArrayList<String>();

        obtainedList.add("One");
        obtainedList.add("Two");
        obtainedList.add("Three");
        obtainedList.add("Four");
        obtainedList.add("Five");
    }

    @Override
    public Component getTableCellEditorComponent(JTable table, Object value, boolean isSelected, int row, int column) {


       if(column == 0) {
           model.removeAllElements();
           for(int i = 0; i < obtainedList.size(); i++) {
               model.addElement(obtainedList.get(i));
            } 
        } else {

             model.removeAllElements();
             String selectedItem = (String) table.getValueAt(row, 0);
             for(int i = 0; i < obtainedList.size(); i++) {
                    if(!selectedItem.equals(obtainedList.get(i)))
                    model.addElement(obtainedList.get(i));
             } 
         } // Close else

        return super.getTableCellEditorComponent(table, value, isSelected, row, column);
     }
    }

Answer 2

尝试这样的事情，你可以在这个例子中更改 DATA，然后重新绘制并执行单元格的渲染器：

 public void example(){  

      TableColumn tmpColum =table.getColumnModel().getColumn(1);
      String[] DATA = { "Data 1", "Data 2", "Data 3", "Data 4" };
      JComboBox comboBox = new JComboBox(DATA);

      DefaultCellEditor defaultCellEditor=new DefaultCellEditor(comboBox);
      tmpColum.setCellEditor(defaultCellEditor);
      tmpColum.setCellRenderer(new CheckBoxCellRenderer(comboBox));
      table.repaint();
   }


/**
   Custom class for adding elements in the JComboBox.
*/
class CheckBoxCellRenderer implements TableCellRenderer {
        JComboBox combo;
        public CheckBoxCellRenderer(JComboBox comboBox) {
            this.combo = new JComboBox();
            for (int i=0; i<comboBox.getItemCount(); i++){
                combo.addItem(comboBox.getItemAt(i));
            }
        }
        public Component getTableCellRendererComponent(JTable jtable, Object value, boolean isSelected, boolean hasFocus, int row, int column) {
            combo.setSelectedItem(value);
            return combo;
        }
    }

Answer 3

removeAllItems() 调用后，将组合框中的项目添加为

  combobox.addItem("one");
  combobox.addItem("two");