Question

我在java中创建了一个Basic计算器应用程序，它有2个JTextFields和1个JComboBox。我想知道是否有办法让JButton检测你在JComboBox中选择的内容，当我用文本字段做它时，它看起来像这样

 static String divide = "/";

if (n == JOptionPane.OK_OPTION) {
                if (symbol.getText().equals(divide)){
                 <code>
              }
         }

有没有类似的方法用JComboBoxs做到这一点？

String[] symbols = {times, minus, plus, divide};

这是JComboBox的内容代码。

Answer 1

您可以使用方法.getSelectedItem()从JComboBox中获取所选项目。

假设你有String [] symbols = {times，minus，plus，divide};作为构造JComboBox时的输入（参见构造函数JComboBox(E[] items)）

JComboBox jcb = new JComboBox(symbols);

//you will see the string you selected
System.out.println(jcb.getSelectedItem());

Answer 2

也许使用动作监听器

String[] quantities1 = {"/","+"};
JComboBox comboBox = new JComboBox(quantities1);
        comboBox.addActionListener(
                new ActionListener(){
                    public void actionPerformed(ActionEvent e){
                        //do stuff when a section is performed
                        //you can use comboBox.getSelectedItem() to get the selected value
                    }
                }            
        );

如何知道你在JComboBox中选择了什么

2 个答案: