java小程序不会在JPanel中运行
我试图在JFrame中的JPanel中运行一个可运行类。程序可以编译，但不能按预期工作。屏幕上应该有一个旋转的立方体，上面有一些菜单。我做错了什么？如果我把T3D类转换成一个小程序，那么这个程序运行得很好，它可以重新绘制，它可以做任何事情。当我尝试放入JFrame（作为Jpanel或applet）时，它不会重新绘制，也不会执行init（）中的内容。谢谢你的帮助
绘图演示类
import javax.swing.*;
import java.awt.geom.*;
import java.awt.*;
import java.awt.Graphics;
import java.applet.Applet;
public class DrawingDemo extends JFrame{
public DrawingDemo()
{
T3D demo = new T3D();
getContentPane().add(demo);
setVisible(true);
setSize(1024,720);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLocationRelativeTo(null);
T3D p = new T3D();
JMenuBar mb = new JMenuBar();
JMenu file = new JMenu("File");
JMenu edit = new JMenu("Edit");
JMenu settings = new JMenu("Settings");
JMenu help = new JMenu("Help");
JMenuItem exit = new JMenuItem(">Exit");
JMenuItem imp = new JMenuItem(">Import");
JMenuItem exp = new JMenuItem(">Export");
JMenuItem sav = new JMenuItem(">Save");
JMenuItem ope = new JMenuItem(">Open");
file.add(ope);
file.add(sav);
file.add(imp);
file.add(exp);
file.add(exit);
mb.add(file);
mb.add(edit);
mb.add(settings);
mb.add(help);
setJMenuBar(mb);
}
public static void main(String[] args)
{
new DrawingDemo();
}
}
3D类
import java.awt.*;
import java.applet.Applet;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.event.*;
import javax.swing.*;
public class T3D extends JPanel implements Runnable {
long nextSecond = System.currentTimeMillis() + 1000;
int framesInLastSecond = 0;
int framesInCurrentSecond = 0;
int[][] LP= new int[19][3];
double pos_camx,pos_camy,pos_camz,rot_camx,rot_camy,xpoint,ypoint,zpoint;
double rot_radx,rot_rady,nclip,xscr,yscr,kx,ky,e;
int pxscr,pyscr,nxscr,nyscr;
public void start1() {
Thread th = new Thread(this);
th.start();
}
public void keyPressed(KeyEvent e) {
switch (e.getKeyCode()){
case KeyEvent.VK_A :
{
pos_camx -= 0.01;
}
case KeyEvent.VK_D :
{
pos_camx += 0.01;
}
case KeyEvent.VK_W :
{
pos_camy += 0.01;
}
case KeyEvent.VK_S :
{
pos_camy -= 0.01;
}
}
}
@Override
public void run(){
// This will reduce the load the applet has on the runtime
// system..
Thread.currentThread().setPriority(1);
while (true) {
e+=0.01;
pos_camx = Math.cos(e);
pos_camy = Math.sin(e);
repaint();
try {
Thread.sleep(20);
} catch (InterruptedException ie) {
}
}
}
public void init() {
LP[0][0] = -1;
LP[0][1] = -1;
LP[0][2] = -1;
LP[1][0] = 1;
LP[1][1] = -1;
LP[1][2] = -1;
LP[2][0] = 1;
LP[2][1] = 1;
LP[2][2] = -1;
LP[3][0] = -1;
LP[3][1] = 1;
LP[3][2] = -1;
LP[4][0] = -1;
LP[4][1] = -1;
LP[4][2] = -1;
LP[5][0] = 1;
LP[5][1] = 1;
LP[5][2] = -1;
LP[6][0] = 1;
LP[6][1] = 1;
LP[6][2] = 1;
LP[7][0] = -1;
LP[7][1] = 1;
LP[7][2] = 1;
LP[8][0] = -1;
LP[8][1] = -1;
LP[8][2] = 1;
LP[9][0] = 1;
LP[9][1] = -1;
LP[9][2] = 1;
LP[10][0] = 1;
LP[10][1] = 1;
LP[10][2] = 1;
LP[11][0] = -1;
LP[11][1] = -1;
LP[11][2] = 1;
LP[12][0] = -1;
LP[12][1] = -1;
LP[12][2] = -1;
LP[13][0] = 1;
LP[13][1] = -1;
LP[13][2] = 1;
LP[14][0] = 1;
LP[14][1] = -1;
LP[14][2] = -1;
LP[15][0] = 1;
LP[15][1] = 1;
LP[15][2] = 1;
LP[16][0] = -1;
LP[16][1] = 1;
LP[16][2] = -1;
LP[17][0] = -1;
LP[17][1] = 1;
LP[17][2] = 1;
LP[18][0] = -1;
LP[18][1] = -1;
LP[18][2] = -1;
pos_camz = 0;
rot_camx = 0;
rot_camy = 0;
rot_radx = 3.1415*rot_camx/180;
rot_rady = 3.1415*rot_camy/180;
nclip = 0.275;
kx = 8.52/getWidth();
ky = 5.46/getHeight();
}
// Drawing instructions…
public void paint(Graphics g) {
super.paint(g);
Graphics2D g1 = (Graphics2D)g;
g1.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g.setColor(Color.black);
xpoint = (double)(LP[0][0])/2;
ypoint = 10 + (double)(LP[0][1])/2;
zpoint = (double)(LP[0][2])/2;
pxscr = (int)(
((xpoint - pos_camx)*Math.cos(rot_radx) + (ypoint + pos_camy)*Math.sin(rot_radx))*nclip
/((ypoint - pos_camy)*Math.cos(rot_radx) + (pos_camx- xpoint)*Math.sin(rot_radx) + 0.0000000012)*100/kx
+ getWidth()/2);
pyscr = (int)(
getHeight()/2-
(((ypoint + pos_camy)*Math.sin(rot_rady) + (zpoint - pos_camz)*Math.cos(rot_rady))*nclip
/((ypoint - pos_camy)*Math.cos(rot_radx) + (pos_camx + xpoint)*Math.sin(rot_radx) + 0.0000000012)*100/ky)
);
for (int i=1; i<19;i++){
xpoint = (double)(LP[i][0])/2;
ypoint = 10 + (double)(LP[i][1])/2;
zpoint = (double)(LP[i][2])/2;
nxscr = (int)(
((xpoint - pos_camx)*Math.cos(rot_radx) + (ypoint + pos_camy)*Math.sin(rot_radx))*nclip
/((ypoint - pos_camy)*Math.cos(rot_radx)+(pos_camx + xpoint)*Math.sin(rot_radx)+0.0000000012)*100/kx
+getWidth()/2);
nyscr = (int)(
getHeight()/2-
(((ypoint + pos_camy)*Math.sin(rot_rady)+(zpoint - pos_camz)*Math.cos(rot_rady))*nclip
/((ypoint - pos_camy)*Math.cos(rot_radx)+(pos_camx + xpoint)*Math.sin(rot_radx)+0.0000000012)*100/ky)
);
g1.drawLine(pxscr,pyscr,nxscr,nyscr);
pxscr = nxscr;
pyscr = nyscr;
}
g.drawString("(" + pxscr + "," + pyscr + ")",20,40);
g.drawString("" + pos_camx + ")",20,60);
g.drawString("" + pos_camy,20,80);
g.drawString("" + rot_camx,20,100);
long currentTime = System.currentTimeMillis();
if (currentTime > nextSecond) {
nextSecond += 1000;
framesInLastSecond = framesInCurrentSecond;
framesInCurrentSecond = 0;
}
framesInCurrentSecond++;
g.drawString(framesInLastSecond + " fps", 20, 20);
}
// The standard Applet “GO” function…
public void start() {
Thread th = new Thread(this);
th.start();
}
}
# 1 楼答案
现在我想我明白你的问题了。您已经使用了一个扩展JApplet的类，并试图将其更改为JPanel，而保持init（）方法和所有内容不变。Swing不是那样工作的。您需要重新编写JApplet类型类，去掉特定于applet的方法，如init（）和start（），而可能在类的构造函数中初始化该代码。例如，您需要了解如何使用JPanel的paintComponent方法和Swing计时器在Swing中创建图形和动画，这种方法很可能会成功