Question

我正在尝试制作一个基本的吉他调音器应用程序，只需在单击按钮时播放相应的音频文件。我正在尝试将吉他的主轴箱图像放入JFrame中，但是在理解Oracle文档时遇到了一些麻烦。有人可以向我解释为什么我的图像不会在此代码中产生吗？

P.S。我知道按钮的绑定位置没有设置在任何特定的地方，我知道没有音频代码集。我想先将按钮放在主轴箱图像上的相应调音栓上。

提前感谢您提供的任何提示或信息！

package guitartuner;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.text.*;
import java.awt.image.*;
import java.io.*;
import javax.imageio.*;


public class GuitarTuner extends JFrame{

private JFrame mainFrame;
private JLabel EJLabel, AJLabel, DJLabel, GJLabel, BJLabel, eJLabel, guitarJLabel,
        bassJLabel, loopJLabel;
private JPanel controlPanel;
private JButton EButton, AButton, DButton, GButton, BButton, eButton;

public class LoadImageApp extends Component{
    BufferedImage img;

    public void paint(Graphics g){
        g.drawImage(img, 0, 0, null);
    }

    public LoadImageApp(){
        try{
            img = ImageIO.read(new File("headstock.jpg"));
        } catch (IOException e){    
        }
    }
    public Dimension getPreferredSize() {
        if (img == null) {
            return new Dimension(100,100);
        } else {
            return new Dimension(img.getWidth(null), img.getHeight(null));
        }
    }
}

public GuitarTuner(){
    createUserInterface();
}

public void createUserInterface(){
    JFrame f = new JFrame("Guitar Tuner");

    f.addWindowListener(new WindowAdapter(){
        public void windowClosing(WindowEvent e){
            System.exit(0);
        }
    });

    f.add(new LoadImageApp());
    f.pack();
    f.setVisible(true);

    guitarJLabel = new JLabel();
    guitarJLabel.setBounds(16, 16, 90, 21);
    guitarJLabel.setText("Guitar");
    f.add(guitarJLabel);

    EButton = new JButton();
    EButton.setBounds(20, 20, 50, 50);
    EButton.setText("E");
    f.add(EButton);

    AButton = new JButton();
    AButton.setBounds(40, 40, 50, 50);
    AButton.setText("A");
    f.add(AButton);

    DButton = new JButton();
    DButton.setBounds(60, 60, 50, 50);
    DButton.setText("D");
    f.add(DButton);

    GButton = new JButton();
    GButton.setBounds(20, 100, 50, 50);
    GButton.setText("G");
    f.add(GButton);

    BButton = new JButton();
    BButton.setBounds(40, 100, 50, 50);
    BButton.setText("B");
    f.add(BButton);

    eButton = new JButton();
    eButton.setBounds(60, 100, 50, 50);
    eButton.setText("e");
    f.add(eButton);

    setTitle("Aaron's Awesome Guitar Tuner");
    setSize (500, 500);
    setVisible(true);
}

public static void main(String[] args) {
    GuitarTuner application = new GuitarTuner();
    application.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}   
}

Answer 1

为JFrame.Create设置LayoutManager并添加所有组件，然后使Frame可见。

public void createUserInterface(){
    JFrame f = new JFrame("Guitar Tuner");

    f.addWindowListener(new WindowAdapter(){
        public void windowClosing(WindowEvent e){
            System.exit(0);
        }
    });

    f.add(new LoadImageApp());
    //set LayoutManager
    f.setLayout(new FlowLayout());

    guitarJLabel = new JLabel();
    guitarJLabel.setBounds(16, 16, 90, 21);
    guitarJLabel.setText("Guitar");
    f.add(guitarJLabel);

    EButton = new JButton();
    EButton.setBounds(20, 20, 50, 50);
    EButton.setText("E");
    f.add(EButton);

    AButton = new JButton();
    AButton.setBounds(40, 40, 50, 50);
    AButton.setText("A");
    f.add(AButton);

    DButton = new JButton();
    DButton.setBounds(60, 60, 50, 50);
    DButton.setText("D");
    f.add(DButton);

    GButton = new JButton();
    GButton.setBounds(20, 100, 50, 50);
    GButton.setText("G");
    f.add(GButton);

    BButton = new JButton();
    BButton.setBounds(40, 100, 50, 50);
    BButton.setText("B");
    f.add(BButton);

    eButton = new JButton();
    eButton.setBounds(60, 100, 50, 50);
    eButton.setText("e");
    f.add(eButton);

    f.pack();
    f.setSize (500, 500);
    f.setTitle("Aaron's Awesome Guitar Tuner");
    f.setVisible(true);
}

我已设置FlowLayout，您可以根据需要添加任何布局。

Answer 2

我对代码中的一些内容并不了解：

为什么使用两个框架（GuitarTuner和Frame f）
类LoadImageApp的目的是什么（它只是为框架绘制背景图像？）

如果您只想在框架背景中绘制图像，则可以通过设置布局管理器和内容窗格（我使用单个框架完成）来执行以下操作：

        package guitartuner;

    import java.awt.BorderLayout;
    import java.awt.FlowLayout;
    import java.awt.event.WindowAdapter;
    import java.awt.event.WindowEvent;

    import javax.swing.ImageIcon;
    import javax.swing.JButton;
    import javax.swing.JFrame;
    import javax.swing.JLabel;


    public class GuitarTuner extends JFrame {

        private JLabel guitarJLabel;
        private JButton EButton, AButton;

        public GuitarTuner() {
            createUserInterface();
        }

        public void createUserInterface() {

            addWindowListener(new WindowAdapter() {
                public void windowClosing(final WindowEvent e) {
                    System.exit(0);
                }
            });

            setLayout(new BorderLayout());
            setContentPane(new JLabel(new ImageIcon("headstock.jpg")));
            setLayout(new FlowLayout());

            this.guitarJLabel = new JLabel();
            this.guitarJLabel.setBounds(16, 16, 90, 21);
            this.guitarJLabel.setText("Guitar");
            add(this.guitarJLabel);

            this.EButton = new JButton();
            this.EButton.setBounds(20, 20, 50, 50);
            this.EButton.setText("E");
            add(this.EButton);

            this.AButton = new JButton();
            this.AButton.setBounds(40, 40, 50, 50);
            this.AButton.setText("A");
            add(this.AButton);

            setTitle("Aaron's Awesome Guitar Tuner");
            setSize(500, 500);
            setVisible(true);
        }

        public static void main(final String[] args) {
            GuitarTuner application = new GuitarTuner();
            application.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        }
    }

Java JFrames中的图像

2 个答案: