我为学习目的编写了一个小文本冒险（控制台）。 现在我想用一些图像调整它，但我无法获得图像 刷新。我究竟做错了什么？有人可以帮我吗？
主要类是GameMaster.java和我用来显示的类 图片是DrawRoom.java
相关代码：
class GameMaster
{
public static void main(String args[])
{
// Doing some stuff here, like building rooms, etc...
// Here I start using images
DrawRoom drawRoom = new DrawRoom();
Thread myThread = new Thread(drawRoom);
myThread.start(); // The first image appears as expected.
// Then in a while loop, I get user input from the console and process it.
// According to which room the user is in, I want to draw the corresponding
//image.
drawRoom.changeImage("Images/SOME-OTHER-IMAGE.JPG");
// This however, does not change the shown image!
}
}
public class DrawRoom extends JPanel implements Runnable{
Image image;
JFrame frame;
public DrawRoom(){
this.image = Toolkit.getDefaultToolkit().getImage("Images/GAME-START.JPG");
this.frame = new JFrame("The Current Image");
this.frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.frame.setSize(640,510);
}
public void paintComponent(Graphics g){
g.drawImage(image,0,0,640,480, this);
}
public static void main(String arg[]){
// Left empty.
}
public void run(){
DrawRoom panel = new DrawRoom();
this.frame.setContentPane(panel);
this.frame.setVisible(true);
}
public void changeImage(String whichImage){
this.image = Toolkit.getDefaultToolkit().getImage(whichImage);
this.frame.revalidate();
this.frame.repaint();
}
}
我是新手，尤其是图形和线程新手。非常感谢帮助！
答案 0 :(得分：3)
您需要调用repaint()本身的DrawRoom方法：
public void changeImage(String whichImage){
this.image = Toolkit.getDefaultToolkit().getImage(whichImage);
this.repaint(); // not this.frame.repaint()!
}
顺便说一下，在System.out.println(whichImage)方法中使用一个好的changeImage来检查代码是否正确调用了它。
编辑：您在DrawRoom内置run()方法，然后将其添加到框架contentPane - 请勿这样做！只需将面板添加到面板的构造函数中即可：
public DrawRoom(){
this.image = Toolkit.getDefaultToolkit().getImage("Images/GAME-START.JPG");
this.frame = new JFrame("The Current Image");
this.frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.frame.setSize(640,510);
this.frame.setContentPane(this);
this.frame.setVisible(true);
}
...
public void run(){
// do not need to create any DrawRoom instances!
}
public void changeImage(String whichImage){
this.image = Toolkit.getDefaultToolkit().getImage(whichImage);
this.repaint();
}
希望现在一切都好。
答案 1 :(得分：2)
我建议您从源代码开始，如下所示。
这样做是让主线程为图像创建显示的框架和面板，然后循环更改图像。在这个例子中，我只有两个来回交换的图像。
在测试时，请确保您的图像位于正确的文件夹中，并确保图像文件的路径正确无误。如果你只看到一个空白的框架，那么不在正确位置的文件对我来说就是问题。
我没有使用多个线程，但这里是Constructing Threads and Runnables的资源。
主要类如下所示：
import javax.swing.*;
public class SimpleThreeTierMain {
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
// Doing some stuff here, like building rooms, etc...
// Here I start using images
DrawRoom drawRoom = new DrawRoom();
JFrame frame;
frame = new JFrame("The Current Image");
frame.setContentPane(drawRoom);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(640,510);
frame.setVisible(true);
// Then in a while loop, I get user input from the console and process it.
// According to which room the user is in, I want to draw the corresponding
//image.
long lTime = 2050;
int iChange = 0;
try {
while (true) {
Thread.sleep (lTime);
if (iChange == 1)
drawRoom.changeImage("0112091252a.jpg");
else
drawRoom.changeImage("0112091251.jpg");
iChange = 1 - iChange;
}
} catch (InterruptedException iex) {}
}
}
绘图室类如下所示：
import javax.swing.*;
import java.awt.*;
public class DrawRoom extends JPanel {
Image image;
public DrawRoom() {
this.image = Toolkit.getDefaultToolkit().getImage("0112091251.jpg");
}
public void paintComponent(Graphics g){
g.drawImage(image,0,0,640,480, this);
}
public void changeImage(String whichImage){
this.image = Toolkit.getDefaultToolkit().getImage(whichImage);
this.repaint();
}
}