JButton没有显示在JFrame中

Question

你好同事！

JButton应该能够显示在JFrame中吗？我在JButton上使用了setVisible方法，但它不会出现。

错误消息：

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，尝试gameFrame.add(gameButton);

Answer 2

你需要添加按钮帧。 如gameFrame.add(gameButton);

Answer 3

将其添加到面板，否则它不会显示，永远。 gameframe.add（gameButton）; gameFrame.add（gameButton）;

Answer 4

您必须添加按钮框架或面板：例如JFrame.add(gameButton);