如何将JFrame设置为JDialog的父级

我无法将框架设置为对话框的所有者。 通常当我扩展JDialog类来创建对话框时，我使用super(frame)来指定对话框的所有者，这样当你按下alt+tab时它们都不会脱节。 但是当我使用new JDialog dialog = new JDialog()创建一个对话框时，我无法将该框架指定为对话框的所有者。

以下示例演示了以上两种方法。 Top Click按钮打开一个不扩展JDialog的对话框。 Bottom Click按钮打开一个扩展JDialog的对话框。

 import java.awt.BorderLayout; import java.awt.Dimension; import java.awt.EventQueue; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.JButton; import javax.swing.JDialog; import javax.swing.JFrame; public class DialogEx { public static void main(String[] args) { Runnable r = new Runnable() { public void run() { new DialogEx().createUI(); } }; EventQueue.invokeLater(r); } private void createUI() { final JFrame frame = new JFrame(); frame.setLayout(new BorderLayout()); JButton button1 = new JButton("Top Click"); JButton button2 = new JButton("Bottom Click"); button2.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent arg0) { new DialogExtend(frame).createUI(); } }); button1.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent event) { new DialogWithoutExtend(frame).cretaUI(); } }); frame.setTitle("Test Dialog Instances."); frame.add(button1, BorderLayout.NORTH); frame.add(button2, BorderLayout.SOUTH); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setSize(new Dimension(300, 200)); frame.setVisible(true); } class DialogExtend extends JDialog { private JFrame frame; public DialogExtend(JFrame frame) { super(frame); this.frame = frame; } public void createUI() { setLocationRelativeTo(frame); setTitle("Dialog created by extending JDialog class."); setSize(new Dimension(400, 100)); setModal(true); setVisible(true); } } class DialogWithoutExtend { private JFrame frame; public DialogWithoutExtend(JFrame frame) { this.frame = frame; } public void cretaUI() { JDialog dialog = new JDialog(); dialog.setTitle("Dialog created without extending JDialog class."); dialog.setSize(new Dimension(400, 100)); dialog.setLocationRelativeTo(frame); dialog.setModal(true); dialog.setVisible(true); } } } 

Answer 1

对话框（或窗口）所有者只能在构造函数中设置，因此设置它的唯一方法是使用以所有者作为参数的构造函数，如：

 class DialogWithoutExtend { private JFrame frame; public DialogWithoutExtend(JFrame frame) { this.frame = frame; } public void cretaUI() { JDialog dialog = new JDialog(frame); dialog.setTitle("Dialog created without extending JDialog class."); dialog.setSize(new Dimension(400, 100)); dialog.setLocationRelativeTo(frame); dialog.setModal(true); dialog.setVisible(true); } }