Java JList 设置项目的颜色

Java JList setting color of items

提问by Jano Nepovinne Bu?fy

could you please help me, how to change color of items showed in JList?

你能帮我吗，如何改变 JList 中显示的项目的颜色？

I'm making an user JList where I can see online and offline users, and I need the offline users to have different colors than online users.

我正在制作一个用户 JList，我可以在其中看到在线和离线用户，我需要离线用户与在线用户具有不同的颜色。

My code for creating users

我创建用户的代码

final String [] strings=database.getUsers(myLogin);  

jList1.setModel(new javax.swing.AbstractListModel() {
     @Override
     public int getSize() { return strings.length; }
     @Override
     public Object getElementAt(int i) { return strings[i]; }
});

采纳答案by mKorbel

• I think that you have to read tutorial How to Use Lists, especially part Writing a Custom Cell Renderer, concept of Renderer is the same for JList, JTableor for JComboBoxtoo

• examples are hereand on this forum here

• 我认为您必须阅读教程如何使用列表，尤其是编写自定义单元格渲染器的部分，渲染器的概念对于JList、JTable或JComboBox也是相同的

• 例子在这里和在这个论坛上

回答by Jar Yit

I hope this code will totally help you

我希望这段代码能完全帮助你

    import java.awt.BorderLayout;
    import java.awt.Color;
    import java.awt.Component;
    import java.awt.EventQueue;
    import java.util.Vector;

   import javax.swing.DefaultListCellRenderer;
   import javax.swing.JFrame;
   import javax.swing.JList;
   import javax.swing.JScrollPane;

   public class UserList {

 public static void main(String[] args) {
      EventQueue.invokeLater(new Runnable() {

           @Override
           public void run() {
                JFrame f = new JFrame("Users");
                f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                f.setSize(300, 300);

                JList list = new JList(new Vector<User>() {
                     {
                          add(new User("A", false));
                          add(new User("B", true));
                          add(new User("C", true));
                          add(new User("D", false));
                     }
                });

                list.setCellRenderer(new DefaultListCellRenderer() {

                     @Override
                     public Component getListCellRendererComponent(JList list, Object value, int index,
                               boolean isSelected, boolean cellHasFocus) {
                          Component c = super.getListCellRendererComponent(list, value, index, isSelected, cellHasFocus);
                          if (value instanceof User) {
                               User nextUser = (User) value;
                               setText(nextUser.name);
                               if (nextUser.loggedIn) {
                                    setBackground(Color.GREEN);
                               } else {
                                    setBackground(Color.RED);
                               }
                               if (isSelected) {
                                    setBackground(getBackground().darker());
                               }
                          } else {
                               setText("whodat?");
                          }
                          return c;
                     }

                });
                f.add(new JScrollPane(list), BorderLayout.CENTER);
                f.setVisible(true);
           }
      });
 }

 static class User {
      String name = "NN";
      boolean loggedIn = false;

      public User(String name, boolean loggedIn) {
           this.name = name;
           this.loggedIn = loggedIn;
      }
 }

}

}