向 JFrame 添加多个按钮，文本 + 颜色不显示

Question

我正在尝试一个接一个地向JPanel添加 10 个按钮，然后将它们全部添加到JFrame中。我需要我的 for 循环，因为它必须很容易更改按钮的数量。所有按钮还需要有不同的颜色和文本(我知道它们可以通过下面的代码获得相同的颜色，但现在没关系(。

我从下面的代码输出只是一个带有 10 个白色按钮且没有文本/颜色的框架。为什么colors、text和actionlistener没有连接到我的按钮？

我已经读过其他问题，我必须小心我关于frame.add(panel、frame.pack()和frame.setVisible(true)的安置，但我认为这些都正确地放在我的forloop之外。我也尝试使用 frame.setContentPane(panel) ，但这给出了相同的结果 - 一个带有 10 个白色按钮且没有文本/颜色的框架。

CMain class ：

public class CMain extends MyButton {
public static void main(String[] args) {
    Random randomGenerator = new Random();
    int numberofbuttons = 10;
    JPanel panel = new JPanel();
    JFrame frame = new JFrame("MyButton testing");
    for (int i = 0; i < numberofbuttons; i++) {
        float r = randomGenerator.nextFloat();float g = randomGenerator.nextFloat();float b = randomGenerator.nextFloat();float r2 = randomGenerator.nextFloat();float g2 = randomGenerator.nextFloat();float b2 = randomGenerator.nextFloat();
        String theText = "SWITCH ME BACK";
        String theOtherText = "button nr: " + i;
        Color theColor = new Color(r, g, b);
        Color theOtherColor = new Color(r2, g2, b2);
        MyButton myb = new MyButton(theColor, theOtherColor, theText, theOtherText);
        panel.add(myb);
    }
    frame.add(panel);
    frame.pack();
    frame.setVisible(true);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}

MyButton class ：

public class MyButton extends JButton implements ActionListener {
private JButton button;
private Color col1;
private Color col2;
private String text1;
private String text2;
public MyButton(Color col1, Color col2, String text1, String text2) {
    this.col1 = col1;
    this.col2 = col2;
    this.text1 = text1;
    this.text2 = text2;
    button = new JButton(text1);
    button.setOpaque(true);
    button.setBackground(col1);
    button.addActionListener(this);
}
public MyButton() {
    this(Color.blue, Color.red, "click = make red", "click = reset to blue");
}
public void ToggleState() {
    Color initialBackground = button.getBackground();
    if (initialBackground == col1) {
        button.setBackground(col2);
        button.setText(text2);
    } else if (initialBackground == col2) {
        button.setBackground(col1);
        button.setText(text1);
    }
}
public void actionPerformed(ActionEvent e) {
    if (e.getSource() == button) {
        this.ToggleState();
    }
}
}

Answer 1

你正在用你的类创建两个 JButtons，一个是类本身的对象(如果你愿意的话，是this(，第二个是类中的button JButton变量：

public class MyButton extends JButton implements ActionListener {  // **** this is a JButton
    private JButton button; // ***** and so is THIS!

去掉button变量，只用this，你的问题可能会得到解决。

public class MyButton extends JButton implements ActionListener {  // this is a JButton
    // private JButton button; // get rid of this
    // and then change all code where you try to use button to this.

例如，

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class MyButton extends JButton implements ActionListener {
    // private JButton button;
    private Color col1;
    private Color col2;
    private String text1;
    private String text2;
    public MyButton(Color col1, Color col2, String text1, String text2) {
        super(text1);   // *********** also add this **********
        this.col1 = col1;
        this.col2 = col2;
        this.text1 = text1;
        this.text2 = text2;
        // button = new JButton(text1);
        this.setOpaque(true);
        this.setBackground(col1);
        this.addActionListener(this);
    }
    public MyButton() {
        this(Color.blue, Color.red, "click = make red", "click = reset to blue");
    }
    public void ToggleState() {
        Color initialBackground = this.getBackground();
        if (initialBackground == col1) {
            this.setBackground(col2);
            this.setText(text2);
        } else if (initialBackground == col2) {
            this.setBackground(col1);
            this.setText(text1);
        }
    }
    public void actionPerformed(ActionEvent e) {
        // if (e.getSource() == button) {
        this.ToggleState();
        // }
    }
}