如何在JOptionPane.showConfirmDialog中处理选项类型

Question

当单击JOptionPane中的按钮时，我需要一种编写一些代码来处理事件的方法。 我实际上是在使用JOptionPane插入用户名和密码，如果单击了正确的OK按钮，则JOptionPane消失，父JFrame保持活动状态，如果单击了Cancel按钮，则程序退出。 我下面的示例代码仅显示JOptionpane，单击任何按钮都将其关闭`JPanel panel = new JPanel（）; panel.setLayout（new GridLayout（4，1））; //使用文本（用户名）创建标签JLabel username = new JLabel（“ Username”）;

    //Create a label with text (Password)
    JLabel password = new JLabel("Password");

    //Create text field that will use to enter username
    JTextField textField = new JTextField(12);

    //Create password field that will be use to enter password
    JPasswordField passwordField = new JPasswordField(12);

    //Add label with text (username) into created panel
    panel.add(username);

    //Add text field into created panel
    panel.add(textField);

    //Add label with text (password) into created panel
    panel.add(password);

    //Add password field into created panel
    panel.add(passwordField);

    //Show JOptionPane that will ask user for username and password
    JOptionPane.showConfirmDialog(mainFrame, panel, "Enter username and password", JOptionPane.OK_CANCEL_OPTION, JOptionPane.QUESTION_MESSAGE);`

Answer 1

这些对话框返回一个int值，该值可以解释为以下值之一：

• YES_OPTION
• NO_OPTION
• CANCEL_OPTION
• OK_OPTION
• CLOSED_OPTION

例如，

final int option = JOptionPane.showConfirmDialog(mainFrame, panel, "Enter username and password", JOptionPane.OK_CANCEL_OPTION, JOptionPane.QUESTION_MESSAGE);
if(option == JOptionPane.OK_OPTION){
    // OK was pressed. Now do stuff.
}
else if(option == JOptionPane.CANCEL_OPTION){
    // Cancel was pressed. Now do stuff.
}

Answer 2

抢救Javadoc ：

返回值：

指示用户选择的选项的int

将结果与JOptionPane中定义的常量（ OK_OPTION ， CANCEL_OPTION ， CLOSED_OPTION等）进行比较