Question

我写了这段代码来显示一个带有三个按钮的窗口。但是，窗口出现但不显示按钮。这是代码：

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import java.awt.BorderLayout;
import javax.swing.*;
import java.awt.*;



public class Test3 extends JFrame{


public Test3() {

    JFrame frame = new JFrame("Exemple");
    JButton button1 = new JButton("Règles");
    button1.setBounds(100, 60, 100, 30);
    JButton button2 = new JButton("Jouer");
    JButton button3 = new JButton("Scores");
    JPanel pane1 = new JPanel(new GridLayout(0, 1));
    this.setVisible(true);

    pane1.add(button1);
    pane1.add(button2);
    pane1.add(button3);
    frame.getContentPane().add(pane1, BorderLayout.EAST);
    this.setVisible(true);
    setSize(800, 600);



}

public static void main(String[] args) {
    Test3 test3 = new Test3();
}

}

有没有人知道如何解决这个问题？

感谢您的帮助！

Agnès

Answer 1

你有两个窗口......

public class Test3 extends JFrame{
    public Test3() {
        JFrame frame = new JFrame("Exemple");

您正在向frame添加内容，但显示Test3 ...

作为一般经验法则，您应该避免从JFrame等顶级容器扩展，而是在需要时创建实例。这将使您从给定的实现中解锁，并允许您灵活地决定如何重用给定的组件，作为示例。

public class Test3 {
    public Test3() {
        JFrame frame = new JFrame("Exemple");
        JButton button1 = new JButton("Règles");
        JButton button2 = new JButton("Jouer");
        JButton button3 = new JButton("Scores");
        JPanel pane1 = new JPanel(new GridLayout(0, 1));

        pane1.add(button1);
        pane1.add(button2);
        pane1.add(button3);
        frame.getContentPane().add(pane1, BorderLayout.EAST);
        frame.pack();
        frame.setVisible(true);
    }

可运行的例子......

import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.awt.GridLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;

public class Test3 {

    public Test3() {

        JFrame frame = new JFrame("Exemple");
        JButton button1 = new JButton("Règles");
        button1.setBounds(100, 60, 100, 30);
        JButton button2 = new JButton("Jouer");
        JButton button3 = new JButton("Scores");
        JPanel pane1 = new JPanel(new GridLayout(0, 1));

        pane1.add(button1);
        pane1.add(button2);
        pane1.add(button3);
        frame.getContentPane().add(pane1, BorderLayout.EAST);
        frame.pack();
        frame.setVisible(true);

    }

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                    ex.printStackTrace();
                }

                Test3 test3 = new Test3();
            }
        });
    }

}

Answer 2

请尝试这样，我已更正

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import java.awt.BorderLayout;
import javax.swing.*;
import java.awt.*;



public class Test3 extends JFrame{


public Test3() {

   super("Exemple");
    JButton button1 = new JButton("Règles");
    button1.setBounds(100, 60, 100, 30);
    JButton button2 = new JButton("Jouer");
    JButton button3 = new JButton("Scores");
    JPanel pane1 = new JPanel(new GridLayout(0, 1));
    this.setVisible(true);

    pane1.add(button1);
    pane1.add(button2);
    pane1.add(button3);
    getContentPane().add(pane1, BorderLayout.EAST);
    this.setVisible(true);
    setSize(800, 600);



}

public static void main(String[] args) {
    Test3 test3 = new Test3();
}

}

窗口显示但不是按钮

2 个答案: