Java Swing 下拉列表
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/22039109/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Java Swing drop down list
提问by user21
I have created a drop down list using JAVA Swing. When I select "Keep track of status of RCM:", I want to create another drop down list next to the option selected. should I use mouseactionlistener instead? I trying to accomplish something like in this, when I click menu options, there is another list which I can select under menu options category. Example : http://smoothjazztampabay.com/wp-content/rockettheme/rt_metropolis_wp/menu-options/dropdownmenu.jpg
我使用 JAVA Swing 创建了一个下拉列表。当我选择“跟踪 RCM 的状态：”时，我想在所选选项旁边创建另一个下拉列表。我应该改用 mouseactionlistener 吗？我试图完成这样的事情，当我单击菜单选项时，我可以在菜单选项类别下选择另一个列表。示例：http: //smoothjazztampabay.com/wp-content/rockettheme/rt_metropolis_wp/menu-options/dropdownmenu.jpg
I tried using this code but couldn't.
我尝试使用此代码但不能。
if (state == ItemEvent.SELECTED)
{
ItemSelectable itemS = itemEvent.getItemSelectable();
String cmd = selectedString(itemS);
if ( cmd.equals("Keep track of status of RCM:"))
{
RCMCombo2.addItem(RCMCombo);
selectionPanel.add(RCMCombo2);
}
The full version of the code is shown as below:
完整版代码如下所示：
String [] RCM2 = {"Keep track of status of RCM:", "Add and activate RCM", "Remove RCM",
"Display the usage statistics for RCM",
"Update capabilities of RCMs", "Show RCM used most frequently in the last n days",
"Display number of times the RCM was emptied in n hours"};
RCMCombo2 = new JComboBox(RCM2);
RCMCombo2.addItemListener(itemListener);
RCMCombo2.setEditable(false);
RCMCombo2.setBounds(10,10,10,30);
//"Updates capabilities of RCM"); Get the location of RCM");
selectionPanel.add(RCMCombo2);
ItemListener itemListener = new ItemListener()
{
public void itemStateChanged(ItemEvent itemEvent)
{
int state = itemEvent.getStateChange();
//System.out.println((state == ItemEvent.SELECTED) ? "Selected" : "Deselected");
//System.out.println("Item: " + itemEvent.getItem());
if (state == ItemEvent.SELECTED)
{
ItemSelectable itemS = itemEvent.getItemSelectable();
String cmd = selectedString(itemS);
if ( cmd.equals("Keep track of status of RCM:"))
{
RCMCombo2.addItem(RCMCombo2);
selectionPanel.add(RCMCombo2);
}
Any help will be appreciated. Thank you.
任何帮助将不胜感激。谢谢你。
回答by SebastianH
It looks like you are on a completely wrong track. I think you are mixing the usage of ItemListenerwith the setup of the lists model.
Check out this guide to ComboBox- it should contain all the information you need.
看起来你走上了完全错误的轨道。我认为您将 的使用ItemListener与列表模型的设置混合在一起。查看ComboBox 指南- 它应该包含您需要的所有信息。
