Question

import javax.swing.*;
import java.awt.event.*;
import java.util.Scanner;
import java.awt.*;
import javax.imageio.ImageIO;                    
import java.awt.image.BufferedImage;     
import java.io.IOException;  
                //////////////////////////////////
                //   3nriched Games Presents:   //
                //      MIPS The Mouse!!        //
                //////////////////////////////////           


public class mipsMouseGUI extends JFrame implements ActionListener
   {

    private static String ThePDub = ("mouse"); //the password
    JPasswordField pass;
    JPanel panel;
    JButton btnEnter;
    JLabel lblpdub;

        public mipsMouseGUI()
        {
        BufferedImage image = null;
        try { //attempts to read picture from the folder
            image = ImageIO.read(getClass().getResource("/mousepics/mousepic.png"));
        } catch (IOException e) {  //catches exceptions
            e.printStackTrace();
        }
        setIconImage(image);  //sets icon picture



            setTitle("Mips The Mouse Login");

            setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

            panel = new JPanel(); //creates a panel
            ImagePanel panel = new ImagePanel(new ImageIcon("/mousepics/backgroundspacepic.jpeg").getImage());

            pass = new JPasswordField(5);  //sets password length to 5          


            pass.setEchoChar('@');   //hide characters as @ symbol
            pass.addActionListener(this);    //adds action listener


            add(panel);  //adds panel to frame
            btnEnter = new JButton("Enter"); //creates a button     
            btnEnter.addActionListener(this);// Register the action listener.

            lblpdub = new JLabel("       Your Password: "); // label that says enter password

            panel.add(lblpdub, BorderLayout.CENTER);//  adds label and inputbox 
            panel.add(pass, BorderLayout.CENTER);   // to panel and sets location
            panel.add(btnEnter, BorderLayout.CENTER); //adds button to panel
            pack();                                         // packs controls and

            setLocationRelativeTo(null);    // Implicit "this" if inside JFrame constructor.

            setVisible(true);                               // makes them visible (duh)

        }

        public void actionPerformed(ActionEvent a)
            {

                Object source = a.getSource();
            //char array that holds password
            char[] passy = pass.getPassword();
            //characters array to string
            String p = new String(passy);

            //determines if user entered correct password
            if(p.equals(ThePDub))
            {
            JOptionPane.showMessageDialog(null, "Welcome beta user: USERNAME.");
            }
            else
            JOptionPane.showMessageDialog(null, "You have enter an incorrect password. Please try again.");
            }

    class ImagePanel extends JPanel {

            private Image img;

        public ImagePanel(String img) {
            this(new ImageIcon(img).getImage());
  }

            public ImagePanel(Image img) {
            this.img = img;
            Dimension size = new Dimension(img.getWidth(null), img.getHeight(null));
            setPreferredSize(size);
            setMinimumSize(size);
            setMaximumSize(size);
            setSize(size);
            setLayout(null);
  }

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

}
        }

Answer 1

图像对我来说很好。您是否添加了任何调试代码以显示图像的首选大小，以确保正确读取它。

此外，一旦图像正常工作，您将看不到实际添加到图像面板的组件。你知道下面的代码行是做什么的，或者你只是从某个地方复制它？摆脱它：

setLayout(null);

为什么要创建一个空面板然后创建一个ImagePanel？

panel = new JPanel(); //creates a panel    
ImagePanel panel = new ImagePanel(new ImageIcon("/mousepics/backgroundspacepic.jpeg").getImage());

Java - 尝试将背景图像设置为我的GUI界面

1 个答案: