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,我使用超级(框架)来指定对话框的所有者,以便当您按Alt选项卡时,它们都不会脱节.但是当我使用新的JDialog对话框= new JDialog()创建一个对话框时,我无法将框架指定为对话框的所有者.
以上示例以上两种方法.顶部点击按钮打开一个没有扩展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);
}
}
}
解决方法
对话框(或窗口)的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将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);
}
}
