Question

您好我正在尝试为我的大学工作设计一个购物车，我目前正在尝试做的是有一个comboBox，当用户点击comboBox中的选项信息时，会显示用户选择的该选项。

我花了一些时间试图查找如何执行此操作，并给出的建议是在comboBox上使用actionListener。我已经添加了一个actionListerner，但是我对下一部分感到困惑。目前，当用户第一次点击选项时，它将正确显示文本，但是如果他选择了另一个选项，则文本将保持不变。我需要找到一种方法来继续运行我的IF语句，以便继续检查已选择的内容。我尝试在我的ActionListener中添加一个while循环，但这似乎没有做到这一点。

以下是Listener中的代码以及我如何创建comboBox及其选项。

组合框

golfBagOptions = new JComboBox（）;

      golfBagOptions.addItem("TaylorMade Juggernaut Cart Bag");
      golfBagOptions.addItem("Mizuno Golf Rider Cart Bag");
      golfBagOptions.addItem("Titleist RC13 Reverse Cart Bag");
      golfBagOptions.addItem("Callaway Golf Euro Chev Org Cart Bag");

的ActionListener

golfBagOptions.addActionListener(new ActionListener(){
        public void actionPerformed(ActionEvent e){

            if (golfBagOptions.getSelectedItem().toString()=="TaylorMade Juggernaut Cart Bag");{
                String startNewLine = System.getProperty("line.separator");
                golfBagInformation.setText("Name : TaylorMade Juggernaut Cart Bag" + startNewLine + "Price: £129" + startNewLine + "Colour: Blue" + startNewLine + 
                        "Description: With powerful looks and crush-resistant construction, the TaylorMade Juggernaut Cart Bag is an intimidating and widely popular golf bag." );
            }
            if (golfBagOptions.getSelectedItem().toString()=="Mizuno Golf Rider Cart Bag");{
                String startNewLine = System.getProperty("line.separator");
                golfBagInformation.setText("Name : Mizuno Golf Rider Cart Bag" + startNewLine + "Price: £99.99" + startNewLine + "Colour: Black" + startNewLine + 
                        "Description: Something which is often difficult to achieve on a busy golf course is that sense of everything in its place. The Mizuno Aerolite 5 Golf Stand Bag has been created with an abundance of storage options, " +
                        "excellent golf club placement and " +
                        "reduces strain on the back when carried." );
            }
            if (golfBagOptions.getSelectedItem().toString()=="Titleist Lightweight SE Stand Bag");{
                String startNewLine = System.getProperty("line.separator");
                golfBagInformation.setText("Name : TaylorMade Juggernaut Cart Bag" + startNewLine + "Price: £99.99" + startNewLine + "Colour: Silver" + startNewLine + 
                        "Description: Carry your golf gear around the golf course effortlessly with the stylish Titleist Lightweight SE Stand Bag. Slip on this comfortable bag and you will be amazed by the " +
                        "lightweight comfort and convenience of a fast stand mechanism with broad foot and tripod rubber feet for ultimate stability." +
                        " The Titleist Lightweight SE Stand Bag is perfect for walking around the course in style." );
            }
            if (golfBagOptions.getSelectedItem().toString()=="Cleveland Golf Lightweight Stand Bag");{
                String startNewLine = System.getProperty("line.separator");
                golfBagInformation.setText("Name : TaylorMade Juggernaut Cart Bag" + startNewLine + "Price: £79.99" + startNewLine + "Colour: Blue" + startNewLine + 
                        "Description: To keep your golf clubs protected both on and off the golf course, the Cleveland Lightweight Stand Bag will assure total comfort, safety and smart construction." );
            }

        }
    });

如果有人能指出我正确的方向，我非常感激。

干杯

Answer 1

更改

  if (golfBagOptions.getSelectedItem().toString()=="TaylorMade Juggernaut Cart Bag");{

到

 if (((String)golfBagOptions.getSelectedItem()).equals("TaylorMade Juggernaut Cart Bag"){

调整所有if条件的更改。

1）从if语句中删除所有分号

2）比较java中的String对象使用.equals（）方法而不是“==”   操作

Answer 2

if (golfBagOptions.getSelectedItem().toString()=="TaylorMade Juggernaut Cart Bag");

首先，if语句之后不应该有; semicolon。

也代替==使用equals方法。

您可以使用enums以更好的方式制作它。

Answer 3

尝试与动作命令进行比较，它可以帮助您

e.getActionCommand();

Answer 4

您不能只存储golfBagOptions.getSelectedItem();的值，然后在if语句中使用它。

这将减少运行时负载。

JComboBox，如何知道一次选择哪个特定选项

4 个答案: