Java 按钮位置和位置不工作

我最近试用了Swing和JavaGUI的在线教程，我决定复制教程代码，但添加了第三个按钮。我尝试添加一个红色的，我成功地添加了（它还没有做任何事情），但是我有一些协调问题。每当我尝试运行它时，都会出现如下情况：

我真正需要帮助的是坐标或帧的大小。我真的不知道该怎么办。我相信这是一个相对简单的问题，但是，谢谢

import javax.swing.*;
import java.awt.Color;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;

public class Test1 implements  ActionListener
{

// Definition of global values and items that are part of the GUI.
int blackScoreAmount = 0;
int greenScoreAmount = 0;
int redScoreAmount = 0;

JPanel titlePanel, scorePanel, buttonPanel;
JLabel blackLabel, greenLabel, redLabel, blackScore, greenScore, redScore;
JButton blackButton, greenButton, redButton, resetButton;

public JPanel createContentPane ()
{

    // We create a bottom JPanel to place everything on.
    JPanel totalGUI = new JPanel();
    totalGUI.setLayout(null);

    // Creation of a Panel to contain the title labels
    titlePanel = new JPanel();
    titlePanel.setLayout(null);
    titlePanel.setLocation(10, 0);
    titlePanel.setSize(180, 30);
    totalGUI.add(titlePanel);

    blackLabel = new JLabel("Black Team");
    blackLabel.setLocation(0, 0);
    blackLabel.setSize(120, 30);
    blackLabel.setHorizontalAlignment(0);
    blackLabel.setForeground(Color.black);
    titlePanel.add(blackLabel);

    greenLabel = new JLabel("Green Team");
    greenLabel.setLocation(130, 0);
    greenLabel.setSize(120, 30);
    greenLabel.setHorizontalAlignment(0);
    greenLabel.setForeground(Color.green);
    titlePanel.add(greenLabel);

    redLabel = new JLabel("Red Team");
    redLabel.setLocation(250, 0);
    redLabel.setSize(120, 30);
    redLabel.setHorizontalAlignment(0);
    redLabel.setForeground(Color.red);
    titlePanel.add(redLabel);

    // Creation of a Panel to contain the score labels.
    scorePanel = new JPanel();
    scorePanel.setLayout(null);
    scorePanel.setLocation(10, 40);
    scorePanel.setSize(180, 30);
    totalGUI.add(scorePanel);

    blackScore = new JLabel(""+blackScoreAmount);
    blackScore.setLocation(0, 0);
    blackScore.setSize(120, 30);
    blackScore.setHorizontalAlignment(0);
    scorePanel.add(blackScore);

    greenScore = new JLabel(""+greenScoreAmount);
    greenScore.setLocation(130, 0);
    greenScore.setSize(120, 30);
    greenScore.setHorizontalAlignment(0);
    scorePanel.add(greenScore);

    redScore = new JLabel(""+redScoreAmount);
    redScore.setLocation(250, 0);
    redScore.setSize(120, 30);
    redScore.setHorizontalAlignment(0);
    scorePanel.add(redScore);

    // Creation of a Panel to contain all the JButtons.
    buttonPanel = new JPanel();
    buttonPanel.setLayout(null);
    buttonPanel.setLocation(10, 80);
    buttonPanel.setSize(380, 80);
    totalGUI.add(buttonPanel);

    // We create a button and manipulate it using the syntax we have
    // used before. Now each button has an ActionListener which posts 
    // its action out when the button is pressed.
    blackButton = new JButton("Black Score");
    blackButton.setLocation(0, 0);
    blackButton.setSize(120, 30);
    blackButton.addActionListener(this);
    buttonPanel.add(blackButton);

    greenButton = new JButton("Green Score");
    greenButton.setLocation(130, 0);
    greenButton.setSize(120, 30);
    greenButton.addActionListener(this);
    buttonPanel.add(greenButton);

    redButton = new JButton("Red Score");
    redButton.setLocation(250, 0);
    redButton.setSize(120, 30);
    redButton.addActionListener(this);
    buttonPanel.add(redButton);

    resetButton = new JButton("Reset Score");
    resetButton.setLocation(0, 40);
    resetButton.setSize(250, 30);
    resetButton.addActionListener(this);
    buttonPanel.add(resetButton);

    totalGUI.setOpaque(true);
    return totalGUI;
}

// This is the new ActionPerformed Method.
// It catches any events with an ActionListener attached.
// Using an if statement, we can determine which button was pressed
// and change the appropriate values in our GUI.
public void actionPerformed(ActionEvent e) 
{
    if(e.getSource() == blackButton)
    {
        blackScoreAmount = blackScoreAmount + 1;
        blackScore.setText(""+blackScoreAmount);
    }
    else if(e.getSource() == greenButton)
    {
        greenScoreAmount = greenScoreAmount + 1;
        greenScore.setText(""+greenScoreAmount);
    }
    else if(e.getSource() == resetButton)
    {
        blackScoreAmount = 0;
        greenScoreAmount = 0;
        blackScore.setText(""+blackScoreAmount);
        greenScore.setText(""+greenScoreAmount);
    }
}

private static void createAndShowGUI() 
{

    JFrame.setDefaultLookAndFeelDecorated(true);
    JFrame frame = new JFrame("Black and Green");

    //Create and set up the content pane.
    Test1 demo = new Test1();
    frame.setContentPane(demo.createContentPane());

    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setSize(280, 190);
    frame.setVisible(true);
}

public static void main(String[] args) 
{
    //Schedule a job for the event-dispatching thread:
    //creating and showing this application's GUI.
    SwingUtilities.invokeLater(new Runnable()
    {
        public void run() 
        {
            createAndShowGUI();
        }
    });
  }
}  

您的机架是280x190：

frame.setSize(280, 190);

然后尝试放置一个红色按钮，x原点为250，宽度大小为120->370。如果添加新元素，只需相应调整窗框大小即可

---

对于这类任务，使用布局可能更好（至少更简单）。

窗口的大小是“硬编码的”：

按钮的大小和位置也是如此：

redButton.setLocation(250, 0);
redButton.setSize(120, 30);

您将一个宽度为120的按钮放在一个280大的框架的250处，这样只有25%的按钮可以看到

您必须调整框架的大小和按钮的位置，使其完全可见且美观

编辑

现在，许多其他回复者建议，如果您想改进您的应用程序，请尝试摆脱所有硬编码值，改用布局管理器

以下是一些很好的解释：

---

去掉所有的

.setLayout（null）废话和使用布局管理器。永远不要手动调整组件大小/定位。相反，使用合适的LayoutManager@kleopatra谢谢，现在我明白为什么了！在错误的方向上遇到问题是学习的一个很好的动力：-）技术上是正确的，尽管没有解决真正的问题（即不使用布局管理器），我只是试图通过尽可能保持代码的方式来回答这个问题。我知道这不是最好的方法，但如果OP遵循这种教程，他可能不知道什么是LayoutManager，他可能会在以后学习。任何没有LayoutManager的教程都应该扔进垃圾桶；-）顺便说一句，这不是我的反对票——但你可能可以通过添加一行建议使用经理来恢复我的反对票。我完全同意你；）我会这么做的，这样做可能会更有效率，而不是把答案胡乱扔给新手。
redButton.setLocation(250, 0);
redButton.setSize(120, 30);