我正在努力尝试在java中进行一些七段显示，但我找不到一种方法来保持GUI对象的更新，而不会闪烁。以下是代码：
import java.awt.*;
import javax.swing.*;
public class PPP extends JFrame{
static digit atp_hundred = new digit(); //Amount to pay
static digit atp_ten = new digit();
static digit atp_unit = new digit();
static digit atp_tenth = new digit();
static digit atp_hundreth = new digit();
static digit ltr_ten = new digit(); //Litres
static digit ltr_unit = new digit();
static digit ltr_tenth = new digit();
static digit ppl_hundred = new digit(); //Pence per litre
static digit ppl_ten = new digit();
static digit ppl_unit = new digit();
static digit ppl_tenth = new digit();
public static void init() {
PPP frame = new PPP();
frame.setSize(1280,800);
frame.setVisible(true);
frame.addWindowListener(new java.awt.event.WindowAdapter() {
public void windowClosing(java.awt.event.WindowEvent windowEvent) {
System.exit(0);
}
});
}
public static void main(String arg[]){
init();
while (true) {
for (int i = 0; i < 10; i++) {
atp_hundred.value = i;
atp_hundred.update();
try {
Thread.sleep(1000);
} catch (Exception e) {
}
}
}
}
public PPP(){
super();
}
public void update(Graphics g) {
paint(g);
}
public void paint(Graphics g){
//this.redraw();
g.setFont(new Font("Copperplate Gothic Light", Font.PLAIN, 30));
String title = "Pete's Petrol Pump Simulation vAlpha0.1";
g.setColor(Color.white);
g.clearRect(0,0,1280,800);
g.setColor(Color.black);
g.drawString(title, (int)(640 - (g.getFontMetrics().getStringBounds(title, g).getWidth() / 2)), 75);
g.drawRoundRect(20,100,625,400,5,5);
g.setFont(new Font("Gill Sans MT", Font.PLAIN, 20));
g.drawString("Amount to Pay: ", 40, 160);
atpCreate(g, 180, 110);
//update(g);
//repaint();
//System.out.println((g.getFontMetrics().getStringBounds("Amount to Pay", g).getWidth()));
}
public void atpCreate(Graphics g, int x, int y) {
atp_hundred.create(x, y);
drawPolygons(g, atp_hundred);
atp_ten.create(x+50,y);
drawPolygons(g, atp_ten);
atp_unit.create(x+100, y);
drawPolygons(g, atp_unit);
g.drawOval(x+145, y+60, 10,10);
atp_tenth.create(x+160, y);
drawPolygons(g, atp_tenth);
atp_hundreth.create(x+210, y);
drawPolygons(g, atp_hundreth);
}
public void drawPolygons(Graphics g, digit d) {
if (d.top) {
g.setColor(Color.green);
g.fillPolygon(d.ptop);
} else {
g.setColor(Color.black);
g.drawPolygon(d.ptop);
}
if (d.topleft) {
g.setColor(Color.green);
g.fillPolygon(d.ptopleft);
} else {
g.setColor(Color.black);
g.drawPolygon(d.ptopleft);
}
if (d.topright) {
g.setColor(Color.green);
g.fillPolygon(d.ptopright);
} else {
g.setColor(Color.black);
g.drawPolygon(d.ptopright);
}
if (d.mid) {
g.setColor(Color.green);
g.fillPolygon(d.pmid);
} else {
g.setColor(Color.black);
g.drawPolygon(d.pmid);
}
if (d.botleft) {
g.setColor(Color.green);
g.fillPolygon(d.pbotleft);
} else {
g.setColor(Color.black);
g.drawPolygon(d.pbotleft);
}
if (d.botright) {
g.setColor(Color.green);
g.fillPolygon(d.pbotright);
} else {
g.setColor(Color.black);
g.drawPolygon(d.pbotright);
}
if (d.bot) {
g.setColor(Color.green);
g.fillPolygon(d.pbot);
} else {
g.setColor(Color.black);
g.drawPolygon(d.pbot);
}
g.setColor(Color.black);
}
}
class digit {
int value = 0;
boolean top = false;
boolean topleft = false;
boolean topright = false;
boolean mid = false;
boolean botleft = false;
boolean botright = false;
boolean bot = false;
public void update() {
switch(value) {
case 0: top = false;
topleft = false;
topright = false;
mid = false;
botleft = false;
botright = false;
bot = false;
break;
case 1: top = false;
topleft = false;
topright = true;
mid = false;
botleft = false;
botright = true;
bot = false;
break;
case 2: top = true;
topleft = false;
topright = true;
mid = true;
botleft = true;
botright = false;
bot = true;
break;
case 3: top = true;
topleft = false;
topright = true;
mid = true;
botleft = false;
botright = true;
bot = true;
break;
case 4: top = false;
topleft = true;
topright = true;
mid = true;
botleft = false;
botright = true;
bot = false;
break;
case 5: top = true;
topleft = true;
topright = false;
mid = true;
botleft = false;
botright = true;
bot = true;
break;
case 6: top = true;
topleft = true;
topright = false;
mid = true;
botleft = true;
botright = true;
bot = true;
break;
case 7: top = true;
topleft = false;
topright = true;
mid = false;
botleft = false;
botright = true;
bot = false;
break;
case 8: top = true;
topleft = true;
topright = true;
mid = true;
botleft = true;
botright = true;
bot = true;
break;
case 9: top = true;
topleft = true;
topright = true;
mid = true;
botleft = false;
botright = true;
bot = true;
break;
}
}
Polygon ptop = new Polygon();
Polygon ptopleft = new Polygon();
Polygon ptopright = new Polygon();
Polygon pmid = new Polygon();
Polygon pbotleft = new Polygon();
Polygon pbotright = new Polygon();
Polygon pbot = new Polygon();
public void create(int x, int y) {
ptop.addPoint(x+10, y);
ptop.addPoint(x+30, y);
ptop.addPoint(x+35, y+5);
ptop.addPoint(x+30, y+10);
ptop.addPoint(x+10, y+10);
ptop.addPoint(x+5, y+5);
ptopleft.addPoint(x+5, y+5);
ptopleft.addPoint(x+10, y+10);
ptopleft.addPoint(x+10, y+30);
ptopleft.addPoint(x+5, y+35);
ptopleft.addPoint(x, y+30);
ptopleft.addPoint(x, y+10);
ptopright.addPoint(x+35, y+5);
ptopright.addPoint(x+40, y+10);
ptopright.addPoint(x+40, y+30);
ptopright.addPoint(x+35, y+35);
ptopright.addPoint(x+30, y+30);
ptopright.addPoint(x+30, y+10);
pmid.addPoint(x+10, y+30);
pmid.addPoint(x+30, y+30);
pmid.addPoint(x+35, y+35);
pmid.addPoint(x+30, y+40);
pmid.addPoint(x+10, y+40);
pmid.addPoint(x+5, y+35);
pbotleft.addPoint(x+5, y+35);
pbotleft.addPoint(x+10, y+40);
pbotleft.addPoint(x+10, y+60);
pbotleft.addPoint(x+5, y+65);
pbotleft.addPoint(x, y+60);
pbotleft.addPoint(x, y+40);
pbotright.addPoint(x+35, y+35);
pbotright.addPoint(x+40, y+40);
pbotright.addPoint(x+40, y+60);
pbotright.addPoint(x+35, y+65);
pbotright.addPoint(x+30, y+60);
pbotright.addPoint(x+30, y+40);
pbot.addPoint(x+10, y+60);
pbot.addPoint(x+30, y+60);
pbot.addPoint(x+35, y+65);
pbot.addPoint(x+30, y+70);
pbot.addPoint(x+10, y+70);
pbot.addPoint(x+5, y+65);
}
}
大多数代码只是添加点，并为七段显示设置类型，但是如果有变化，我找不到更新它的好方法。
由于