Question

我有一个客户对象列表。我想为List中的每个对象创建JButtons。这是我到目前为止的代码，

public class Customer_List extends javax.swing.JFrame {

List<Customers> cus_list = new ArrayList();

public Customer_List() {

    cus_list = showCustomers();
    contentPane = new JPanel();
    displayCustomers();
    initComponents(); 
}

public void displayCustomers(){
    JButton[] buttons  = new JButton[cus_list.size()];
    System.out.println(cus_list.size());
    for(int i = 0; i < cus_list.size(); i++){
       buttons[i] = new JButton();
       buttons[i].setText(cus_list.get(i).getName());
     contentPane.add(buttons[i]);
    }
   add(contentPane);
   contentPane.validate();
}

我是一个相当新的挥杆。当我运行它时，JPanel显示但没有按钮。如果我删除initcomponents（）方法，按钮会显示但没有JPanel。我究竟做错了什么？这是initcomponent方法的内容，

  private void initComponents() {

    contentPane = new javax.swing.JPanel();
    jLabel1 = new javax.swing.JLabel();

    setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

    contentPane.setBorder(javax.swing.BorderFactory.createTitledBorder("Customer List"));
    contentPane.setMinimumSize(new java.awt.Dimension(500, 500));

    jLabel1.setText("Customer List");

    javax.swing.GroupLayout contentPaneLayout = new javax.swing.GroupLayout(contentPane);
    contentPane.setLayout(contentPaneLayout);
    contentPaneLayout.setHorizontalGroup(
        contentPaneLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(contentPaneLayout.createSequentialGroup()
            .addGap(190, 190, 190)
            .addComponent(jLabel1)
            .addContainerGap(233, Short.MAX_VALUE))
    );
    contentPaneLayout.setVerticalGroup(
        contentPaneLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(contentPaneLayout.createSequentialGroup()
            .addContainerGap()
            .addComponent(jLabel1)
            .addContainerGap(452, Short.MAX_VALUE))
    );

    javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
    getContentPane().setLayout(layout);
    layout.setHorizontalGroup(
        layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(layout.createSequentialGroup()
            .addContainerGap()
            .addComponent(contentPane, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
            .addContainerGap())
    );
    layout.setVerticalGroup(
        layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(layout.createSequentialGroup()
            .addContainerGap()
            .addComponent(contentPane, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
            .addContainerGap())
    );

    pack();
}// </editor-fold>

`

通过for循环将JButtons添加到JPanel

0 个答案: