CODEWITHSUNDEEP
javauser-interface
PhilFreecess
PhilFreecess

Reputation: 53

JAVA GUI code didn't run as expected

I typed this code from the book

public class SimpleGui3C  {

JFrame frame;


public static void main (String[] args) {
   SimpleGui3C gui = new SimpleGui3C();
   gui.go();
}

public void go() {
   frame = new JFrame("My own code");
   frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

  
   MyDrawPanel drawPanel = new MyDrawPanel();

   frame.getContentPane().add(BorderLayout.CENTER, drawPanel);

   frame.setSize(420,300);
   frame.setVisible(true);
}}

class MyDrawPanel extends JPanel {

public void painComponent(Graphics g) {
    
    g.fillRect(0,0,this.getWidth(), this.getHeight());

    
    int red = (int) (Math.random() * 255);
    int green = (int) (Math.random() * 255);
    int blue = (int) (Math.random() * 255);

    Color randomColor = new Color(red, green, blue);
    g.setColor(randomColor);
    g.fillOval(70,70,100,100);
}}

the result is: enter image description here

Here is the original code of the book, I downloaded this code from the book's website

public class SimpleGui3C  {

JFrame frame;

public static void main (String[] args) {
   SimpleGui3C gui = new SimpleGui3C();
   gui.go();
}

public void go() {
   frame = new JFrame();
   frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

  
   MyDrawPanel drawPanel = new MyDrawPanel();
   

   frame.getContentPane().add(BorderLayout.CENTER, drawPanel);


   frame.setSize(420,300);
   frame.setVisible(true);
}}

class MyDrawPanel extends JPanel {

  public void paintComponent(Graphics g) {
     
     g.fillRect(0,0,this.getWidth(), this.getHeight());

     // make random colors to fill with
     int red = (int) (Math.random() * 255);
     int green = (int) (Math.random() * 255);
     int blue = (int) (Math.random() * 255);

     Color randomColor = new Color(red, green, blue);
     g.setColor(randomColor);
     g.fillOval(70,70,100,100);
  }}

the result goes like this: enter image description here

I checked it again and again to make sure that they're the same, and it seems that they are the same. but why the GUIs are different?

please help, thanks in advance.

Upvotes: 1

Views: 49

Answers (1)

David Tanzer
David Tanzer

Reputation: 2742

In your own code, the method name is painComponent when it should be paintComponent.

Hint: Add @Override to overriden methods, then the compiler will tell you about errors like this:

@Override
public void painComponent(Graphics g) {

Upvotes: 5

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