如何处理 JOptionPane.showConfirmDialog 中的选项类型

Question

当单击 JOptionPane 中的按钮时，我需要编写一些代码来处理事件。我实际上是在使用 JOptionPane 插入用户名和密码，如果单击正确和确定按钮，则 JOptionPane 消失并且父 JFrame 保持活动状态，如果单击取消按钮，程序退出。我下面的示例代码仅显示了 JOptionpane 并单击任何按钮将其关闭 `JPanel 面板 = 新的 JPanel(); panel.setLayout(new GridLayout(4, 1)); //创建一个带有文本的标签（用户名） JLabel 用户名 = new JLabel("用户名");

    //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，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

Javadoc 救援：

返回：

表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