JComboBox监听器

Question

我想根据JComboBox更改按钮的功能。

例如，当我选择单数和复数名词时，按钮的行为应该更改为此项，而当我从JComboBox按钮中选择另一项时，按钮的行为应该相应地更改。

Answer 1

您可以将监听程序添加到组合框中：

//In your class
comboList.addActionListener(this);

然后，在ActionPerformed中，您可以更改所需功能的按钮的侦听器：

//In your class
JButton btn1 = new JButton("Button1");

--------------------------------------------------------

// Your actionPerformed for combo box listener
 public void actionPerformed(ActionEvent e) {
        JComboBox cb = (JComboBox)e.getSource();
        String itemName = (String)cb.getSelectedItem();
        if(itemName.equals("str"){

           //checking if you are not adding listener twice
           if(btn1.getActionListeners().length > 0){
                //remove all the existing listener, iterate and remove if more than one
                btn1.removeActionListener(existingListener);                    
           }
           btn1.addActionListener(new ButtonListener1());
        }
        if(itemName.equals("str2"){
           //follow same process as for above if
        }
    }