JButton not showing up in JFrame

Question

Hello fellow programmers!

Are JButtons supposed to be able to show up in JFrame? I used the setVisible method on JButton but it would not appear.

Error Message:

Exception in thread "main" java.lang.IllegalArgumentException: adding a window to a container
    at java.awt.Container.checkNotAWindow(Unknown Source)
    at java.awt.Container.addImpl(Unknown Source)
    at javax.swing.AbstractButton.addImpl(Unknown Source)
    at java.awt.Container.add(Unknown Source)
    at FrameTest.initializeGameFrame(FrameTest.java:27)
    at FrameTest.main(FrameTest.java:17)

Code:

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;


public class FrameTest extends JFrame{

    private static final int gameWindowHeight = 700;
    private static final int gameWindowLength = 700;

    /** Set up frame for game window
     * 
     */

    public static void main(String[] args)
    {
        FrameTest.initializeGameFrame();

    }

    public static void initializeGameFrame()
    {
        FrameTest gameFrame = new FrameTest();
        gameFrame.setSize(gameWindowLength, gameWindowHeight);
        gameFrame.setTitle("Frame Test- by Me");
        JButton gameButton =  new JButton("Start Game");
        gameButton.add(gameFrame);
        gameButton.setLocation(250, 250);
        gameButton.setVisible(true);
        gameFrame.setVisible(true);

    }


}

Answer 1

您需要将按钮添加到框架中，请尝试gameFrame.add(gameButton);

Answer 2

you need to add button to frame. such as gameFrame.add(gameButton);

Answer 3

Add it to the panel otherwise it won't show up, ever. gameFrame.add(gameButton);

Answer 4

您必须将按钮添加到框架或面板：例如JFrame.add(gameButton);