我正在研究Java中的老虎机，到目前为止我创建了一个随机生成两张图片的按钮。由于某种原因，其中一张图片显示而另一张图片没有显示。我不明白这个问题，因为这两张图片的代码完全相同。这是我的代码。请帮忙！
import java.applet.*;
import java.awt.*;
import javax.swing.JButton;
import javax.swing.JApplet;
import javax.swing.*;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import java.util.Random;
import javax.imageio.*;
import java.net.URL;
import java.io.*;
import java.awt.image.*;
public class slotmachine extends JApplet implements Runnable {
JButton b1 = new JButton("START");
JPanel p;
int int1, int2;
BufferedImage img= null;
BufferedImage img2 = null;
BufferedImage img3 = null;
BufferedImage img4 = null;
BufferedImage img5 = null;
BufferedImage img6 = null;
BufferedImage img7 = null;
BufferedImage img8 = null;
BufferedImage img9 = null;
BufferedImage img10 = null;
public slotmachine(){
init();
}
public void init() {
this.setLayout(null);
this.setSize(10000,10000);
b1.setBounds(100,100,100,100);
b1.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e){
Random random1 = new Random();
int1 = random1.nextInt(10);
Random random2 = new Random();
int2 = random2.nextInt(10);
repaint();
}
});
getContentPane().add(b1);
try {
img = ImageIO.read(new File("question.png"));
img2 = ImageIO.read(new File("banana.png"));
img3 = ImageIO.read(new File("chocolate.png"));
img4 = ImageIO.read(new File("icecream.png"));
img5 = ImageIO.read(new File("bell.png"));
img6 = ImageIO.read(new File("apple.png"));
img7 = ImageIO.read(new File("money.png"));
img8 = ImageIO.read(new File("number-7.png"));
img9 = ImageIO.read(new File("necklace.png"));
img10 = ImageIO.read(new File("gloves.png"));
} catch (IOException e) {
}
repaint();
this.setVisible(true);
}
public void paint(Graphics g) {
super.paintComponents(g);
g.drawString("Int 1 is" + int1,30,30);
g.drawString("Int 2 is" + int2,30,80);
switch (int1) {
case 0:
g.setColor(Color.white);
g.fillRect(300,300,300,500);
g.drawImage(img, 300, 500, this);
break;
case 1:
g.setColor(Color.white);
g.fillRect(300,300,300,500);
g.drawImage(img2,300,500,this);
break;
case 2:
g.setColor(Color.white);
g.fillRect(300,300,300,500);
g.drawImage(img3,300,500,this);
break;
case 3:
g.setColor(Color.white);
g.fillRect(300,300,300,500);
g.drawImage(img4,300,500,this);
break;
case 4:
g.setColor(Color.white);
g.fillRect(300,300,300,500);
g.drawImage(img5,300,500,this);
break;
case 5:
g.setColor(Color.white);
g.fillRect(300,300,300,500);
g.drawImage(img6,300,500,this);
break;
case 6:
g.setColor(Color.white);
g.fillRect(300,300,300,500);
g.drawImage(img7,300,500,this);
break;
case 7:
g.setColor(Color.white);
g.fillRect(300,300,300,500);
g.drawImage(img8,300,500,this);
break;
case 8:
g.setColor(Color.white);
g.fillRect(300,300,300,500);
g.drawImage(img9,300,500,this);
break;
case 9:
g.setColor(Color.white);
g.fillRect(300,300,300,500);
g.drawImage(img10,300,500,this);
break;
}
switch (int2) {
case 0:
g.setColor(Color.white);
g.fillRect(300,300,800,500);
g.drawImage(img, 800, 500, this);
break;
case 1:
g.setColor(Color.white);
g.fillRect(300,300,800,500);
g.drawImage(img2,800,500,this);
break;
case 2:
g.setColor(Color.white);
g.fillRect(300,300,800,500);
g.drawImage(img3,800,500,this);
break;
case 3:
g.setColor(Color.white);
g.fillRect(300,300,800,500);
g.drawImage(img4,800,500,this);
break;
case 4:
g.setColor(Color.white);
g.fillRect(300,300,800,500);
g.drawImage(img5,800,500,this);
break;
case 5:
g.setColor(Color.white);
g.fillRect(300,300,800,500);
g.drawImage(img6,800,500,this);
break;
case 6:
g.setColor(Color.white);
g.fillRect(300,300,800,500);
g.drawImage(img7,800,500,this);
break;
case 7:
g.setColor(Color.white);
g.fillRect(300,300,800,500);
g.drawImage(img8,800,500,this);
break;
case 8:
g.setColor(Color.white);
g.fillRect(300,300,800,500);
g.drawImage(img9,800,500,this);
break;
case 9:
g.setColor(Color.white);
g.fillRect(300,300,800,500);
g.drawImage(img10,800,500,this);
break;
}
this.setVisible(true);
}
}
答案 0 :(得分：2)
img10 = ImageIO.read(new File("gloves.png"));
} catch (IOException e) {
}
该代码有两个问题。
File，具有所有权限的小程序只能使用客户端计算机上的File。由于这些图像显然是应用程序资源（即由您提供），因此它们需要位于服务器上（或至少在applet的运行时类路径上）并由URL加载。这个问题忽略了异常！将其更改为：
} catch (IOException e) {
e.printStackTrace();
}
当然，请确保将Java Console配置为显示。如果默认级别没有输出，请提高级别并再次尝试。
答案 1 :(得分：0)
而不是扩展JApplet并覆盖它的paint和init方法，只需使用JLabel并将其设置为具有图像图标。
例如。
import java.io.File;
import java.util.ArrayList;
import java.util.Random;
import javax.swing.ImageIcon;
public class Frame extends javax.swing.JFrame{
//Random varible
private Random rand = new Random();
//Array List to hold the file names and locations
private ArrayList<File> pictures;
//Class call
public Frame(){
initComponents();
}
//Generates the gui. I Used netbeans to make this for me.
private void initComponents() {
pictureLable1 = new javax.swing.JLabel();
pictureLable2 = new javax.swing.JLabel();
generateButton = new javax.swing.JButton();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
generateButton.setText("Generate");
generateButton.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
generateButtonActionPerformed(evt);
}
});
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addComponent(pictureLable1, javax.swing.GroupLayout.PREFERRED_SIZE, 175, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(31, 31, 31)
.addComponent(pictureLable2, javax.swing.GroupLayout.DEFAULT_SIZE, 174, Short.MAX_VALUE)
.addContainerGap())
.addGroup(layout.createSequentialGroup()
.addGap(151, 151, 151)
.addComponent(generateButton)
.addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
.addComponent(pictureLable2, javax.swing.GroupLayout.DEFAULT_SIZE, 116, Short.MAX_VALUE)
.addComponent(pictureLable1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 139, Short.MAX_VALUE)
.addComponent(generateButton)
.addContainerGap())
);
pack();
}
private void generateButtonActionPerformed(java.awt.event.ActionEvent evt) {
this.generate();
}
/**
* Generates the picture and then sets the labels accordingly.
*/
public void generate(){
//Init the array list
pictures = new ArrayList<>();
//Add the pictures to the array list
pictures.add(new File("C:/Users/UserName/Desktop/TestPictures/Picture1.png"));
pictures.add(new File("banana.png"));
pictures.add(new File("chocolate.png"));
pictures.add(new File("icecream.png"));
pictures.add(new File("bell.png"));
pictures.add(new File("apple.png"));
pictures.add(new File("money.png"));
pictures.add(new File("number-7.png"));
pictures.add(new File("necklace.png"));
pictures.add(new File("gloves.png"));
//Gets the random number for the picture
int number = rand.nextInt((pictures.size() -1/*Max*/ - 0/*min*/) + 1) + 0/*Min*/;
//Set the image icon to a randomly chosen image
this.pictureLable1.setIcon(new ImageIcon(pictures.get(number).getAbsolutePath()));
//Gets the random number again for the second picture
number = rand.nextInt((pictures.size() -1/*Max*/ - 0/*min*/) + 1) + 0/*Min*/;
//Set the second image icon to a randomly chosen image
this.pictureLable1.setIcon(new ImageIcon(pictures.get(number).getAbsolutePath()));
}
/**
* Your run of mill main method.
*
* @param args
*/
public static void main(String args[]){
new Frame().setVisible(true);
}
// Variables declaration
public javax.swing.JButton generateButton;
public static javax.swing.JLabel pictureLable1;
public static javax.swing.JLabel pictureLable2;
}
希望这有帮助。
编辑：
确保将路径名设置为第一个图像，以便java知道图像的位置。
另外，请尽量不要在开头使用非大写字母命名您的课程，使用Frame代替frame，只需要良好的练习：）。