靠近JFrame窗口

Question

我有一个JFrame，我想按"；X〃；键(关闭JFrame(来确认我是否真的想关闭应用程序。如果我点击"；"否"；，它关闭应用程序。

如果我选择"；否"；？

setDefaultCloseOperation(javax.swing.WindowConstants.DO_NOTHING_ON_CLOSE);
addWindowListener(new java.awt.event.WindowAdapter() {
@Override
public void windowClosing(java.awt.event.WindowEvent evt){
if (JOptionPane.showConfirmDialog(rootPane, "Confirm out?", 
"AppLocal", JOptionPane.ERROR_MESSAGE) == JOptionPane.ERROR_MESSAGE){
dispose();
}
}
});

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Answer 1

方法：
int javax.swing.JOptionPane.showConfirmDialog(Component parentComponent, Object message, String title, int optionType) throws HeadlessException

在optionType参数中，您必须使用：

• JOptionPane.YES_NO_OPTION
• JOptionPane.YES_NO_CANCEL_OPTION
• JOptionPane.OK_CANCEL_OPTION

可用的返回值为：

//
// Return values.
//
/** Return value from class method if YES is chosen. */
public static final int         YES_OPTION = 0;
/** Return value from class method if NO is chosen. */
public static final int         NO_OPTION = 1;
/** Return value from class method if CANCEL is chosen. */
public static final int         CANCEL_OPTION = 2;
/** Return value form class method if OK is chosen. */
public static final int         OK_OPTION = 0;
/** Return value from class method if user closes window without selecting
* anything, more than likely this should be treated as either a
* <code>CANCEL_OPTION</code> or <code>NO_OPTION</code>. */
public static final int         CLOSED_OPTION = -1;

因此，您的代码可以是：

setDefaultCloseOperation(javax.swing.WindowConstants.DO_NOTHING_ON_CLOSE);
addWindowListener(new java.awt.event.WindowAdapter() {
@Override
public void windowClosing(java.awt.event.WindowEvent evt) {
if (JOptionPane.showConfirmDialog(rootPane, "Confirm out?", 
"AppLocal", JOptionPane.YES_NO_OPTION) == JOptionPane.YES_OPTION
) {
dispose();
}
}
});