我打算把新建的窗口的背景设计为红色,怎么出来的窗口颜色没变还是默认的颜色
import java.awt.*;
import javax.swing.*;
public class primaryFrame extends JFrame{
public primaryFrame( ){
setTitle("welcome using");
setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setVisible(true);
}
public static final int DEFAULT_WIDTH=300;
public static final int DEFAULT_HEIGHT=400;
public static void main(String[] args ){
primaryFrame myframe=new primaryFrame( );
myframe.setBackground(Color.RED);
}
}
import java.awt.*;
import javax.swing.*;
public class primaryFrame extends JFrame{
public primaryFrame( ){
setTitle("welcome using");
setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setVisible(true);
}
public static final int DEFAULT_WIDTH=300;
public static final int DEFAULT_HEIGHT=400;
public static void main(String[] args ){
primaryFrame myframe=new primaryFrame( );
myframe.setBackground(Color.RED);
}
}
JPanel contentPane;
BorderLayout borderLayout1 = new BorderLayout(); public Frame1() {
try {
setDefaultCloseOperation(EXIT_ON_CLOSE);
jbInit();
} catch (Exception exception) {
exception.printStackTrace();
}
} /**
* Component initialization.
*
* @throws java.lang.Exception
*/
private void jbInit() throws Exception {
contentPane = (JPanel) getContentPane();
contentPane.setLayout(borderLayout1);
setSize(new Dimension(400, 300));
setTitle("Frame Title");
}
public void paint(Graphics g) {
g.setColor(Color.red);
g.fill3DRect(0,0,this.getWidth(),this.getHeight(),true);
}
public static void main(String[] args) {
new Frame1().setVisible(true);
}
}
public void paint(Graphics g) {
g.setColor(Color.red);
g.fill3DRect(0,0,this.getWidth(),this.getHeight(),true);
}