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Thread: Cannot use "this" in a static context

  1. #1
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    Default Cannot use "this" in a static context

    Hello all, I am new to JAVA programming, so I started a few days ago with my first program.

    I found an example at YouTube with the code attached below.

    However, the following message appears:

    Exception in thread "main" java.lang.Error: Unresolved compilation problem:
    Cannot use "this" in a static context

    I have searched on the internet, but unfortunately without any success.

    If I change "this" to "null", then I can run the program , however nothing happens if I hit the button.

    Any idea where I should find this problem?

    Thanks in advance.

    button.addActionListener(this);

    public class Main implements ActionListener {	
     
    public static void main(String[] args) {
     
    		int top=500, left=130, bottom=130, right=500;
     
    		JFrame frame = new JFrame();
    		JButton button = new JButton("Click me");
    		button.addActionListener(this);
     
                    JLabel label = new JLabel("Number of clicks");			
    		JPanel panel = new JPanel();
     
    		panel.setBorder(BorderFactory.createEmptyBorder(top, left, bottom, right));
    		panel.setLayout(new GridLayout(0,1));
    		panel.add(button);
      		panel.add(label);
     
    		frame.add(panel, BorderLayout.CENTER);
    		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    		frame.setTitle("Title");
    		frame.pack();
    		frame.setVisible(true);		
     
     
    	}   // End Static Main

  2. #2
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    Default Re: Cannot use "this" in a static context

    Cannot use "this" in a static context
    this refers to the current instance of the class the statement using this is in. A static context is not in an instance of the class.

    If you want to use this, create an instance of the class where the statement is located.
    Change the main method to create an instance of the class and add a constructor. Move the code that is in the main method to the constructor.
    For example:
       ... main(String[] args) {
        new TheClass();
     } // end main method
    public TheClass() { //  start constructor
     ...// code from main method here
    If you don't understand my answer, don't ignore it, ask a question.

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