JButton没有出现在JFrame中

Question

Hello其他程序员！

JButtons是否应该能够在JFrame中显示？我在JButton上使用了setVisible方法，但它不会出现。

错误讯息：

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)

代码：

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，尝试gameFrame.add(gameButton);

Answer 2

您需要添加按钮到框架。 例如gameFrame.add(gameButton);

Answer 3

将其添加到面板中，否则它将无法显示。      gameFrame.add（gameButton）;

Answer 4

您必须向框架或面板添加按钮：例如JFrame.add(gameButton);