Java-Swing GUI窗口顺序

Question

In the following code, why is the "My Application" window the window at the front? The main method constructs this window first, right? So shouldn't it be at the back when the "My Window" JFrame is produced?

public class MyApp extends JFrame {
public MyApp() { 
super();
setSize(300,600); 
setTitle("My Application"); 
setVisible(true);
}
public static void main(String[] args) { 
MyApp application = new MyApp(); 
JFrame window = new JFrame(); 
window.setSize(600,300); 
window.setTitle("My Window"); 
window.setVisible(true);
} 
}

Answer 1

This is simply undefined behavior; there's no guarantee that either window will always be in front. When I ran your code (Mac OS X, Java 6), "My Window" came up in front, but I have no doubt you're correctly describing what happens on your system.

Answer 2

1) you can't move one JFrame toFront() over another JFrame

2) don't create more than one JFrame , there are another issues with this Top-Level Container as toFront , toBack

3) you have look at JDialog or JWindow as another Window

• with parent to the JFrame

• with setModal if required

• with ModalityTypes is required