问题描述
我有一个使用图形g用各种物体制作的汽车，我想在按下按钮时移动它。有了这个，我没有问题，但我的路径有问题。当汽车移动时，旧位置不会被清除。
I have a "car" made with various objects using graphics g and I want to move it when a button is pressed. With that, I had no problem, but I have a problem with its path. When the car is moved, the old position is not cleared out.
汽车代码（按下按钮时移动）：
Code of the car (to move when button is pressed):
static void gPostavi2(Graphics g){
Graphics2D g2d = (Graphics2D) g;
for(int x=500; x>89; x--){
//risanje
g2d.setColor(Color.blue);
g2d.fillRect(x+10, 351, 118, 23);
g2d.fillRect(x+12, 321, 30, 40);
g2d.fillRect(x+45, 330, 83, 20);
g2d.setColor(Color.black);
g2d.fillOval(x+19, 362, 20, 20);
g2d.fillOval(x+90, 362, 20, 20);
g2d.drawString("2t", x+70, 344);
try {
Thread.sleep(5);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
在这个类中只有方法为了移动东西，该类扩展了另一个具有非移动对象，按钮，标签......和paintComponent方法的类。
In this class are only methods for moving things around, the class extends another that has non-moving objects, buttons, labels,... and the paintComponent method.
每次for语句出现时我如何清除旧位置？
How can I clear the old position, every time the for statement goes around ?
编辑：更多代码在这里。在主类我只有这个代码：
some more code down here. In the main class I have only this code:
public static void main(String[] args) {
staticnaGrafika.dodajGumbe();
}
在staticnaGrafika我有很多代码，但这是paintComponent的开始：
In staticnaGrafika I have a ton of code, but this is the beginning of paintComponent:
public class staticnaGrafika extends JPanel{
staticnaGrafika(){
setBorder(BorderFactory.createLineBorder(Color.black));
}
public Dimension getPreferredSize(){
return new Dimension(1100, 740);
}
public void paintComponent(Graphics g){
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g;
g2d.setColor(Color.RED);
//opticno stikalo
//preveri, ce ga plosca prekriva pri max. dvigu
g2d.setColor(Color.black);
g2d.fillOval(21, 148, 33, 33);
g2d.setColor(Color.yellow);
g2d.fillOval(22, 149, 31, 31);
g2d.setColor(Color.black);
g2d.fillRect(13, 159, 11, 1); //el. prikljucnice
g2d.fillRect(13, 166, 10, 1);
g2d.drawOval(7, 157, 5, 5);
g2d.drawOval(7, 164, 5, 5);
//naslon; spodnji omejevalec hoda bata
g2d.setColor(Color.black);
g2d.fillRect(5, 350, 13, 43);
g2d.fillRect(5, 380, 63, 13);
g2d.fillRect(262, 350, 408, 13);
g2d.fillRect(262, 350, 13, 43);
g2d.fillRect(212, 380, 63, 13);
这里只画画。下面我有另一个方法，它添加了按钮，actionListeners：
there is just painting in here. Below I have another method, which adds buttons, actionListeners:
public static void dodajGumbe() {
final JFrame f = new JFrame();
//dvig, stop, spust
JButton dvig = new JButton("DVIGNI");
dvig.setBackground(Color.WHITE);
dvig.setFocusPainted(false);
dvig.setBounds(850,15,120,30);
JButton stop = new JButton("STOP");
stop.setBackground(Color.WHITE);
stop.setFocusPainted(false);
stop.setBounds(850,50,120,30);
JButton spust = new JButton("SPUSTI");
spust.setBackground(Color.WHITE);
spust.setFocusPainted(false);
spust.setBounds(850,85,120,30);
//komande bremen
JButton postavi2 = new JButton("nalozi breme");
postavi2.setBackground(Color.WHITE);
postavi2.setFocusPainted(false);
postavi2.setBounds(760,240,120,30);
JButton odvzemi2 = new JButton("razlozi breme");
odvzemi2.setBackground(Color.WHITE);
odvzemi2.setFocusPainted(false);
odvzemi2.setBounds(760,275,120,30);
JButton postavi5 = new JButton("nalozi breme");
postavi5.setBackground(Color.WHITE);
postavi5.setFocusPainted(false);
postavi5.setBounds(760,330,120,30);
JButton odvzemi5 = new JButton("razlozi breme");
odvzemi5.setBackground(Color.WHITE);
odvzemi5.setFocusPainted(false);
odvzemi5.setBounds(760,365,120,30);
Container gumbi = f.getContentPane();
spust.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent arg0) {
dinamicnaGrafika.gSpusti(f.getGraphics());
}});
dvig.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent arg0) {
dinamicnaGrafika.gDvigni(f.getGraphics());
}});
stop.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent arg0) {
dinamicnaGrafika.gStop(f.getGraphics());
}});
postavi2.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent arg0) {
dinamicnaGrafika.gPostavi2(f.getGraphics());
}});
odvzemi2.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent arg0) {
dinamicnaGrafika.gOdvzemi2(f.getGraphics());
}});
postavi5.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent arg0) {
dinamicnaGrafika.gPostavi5(f.getGraphics());
}});
odvzemi5.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent arg0) {
dinamicnaGrafika.gOdvzemi5(f.getGraphics());
}});
gumbi.add(dvig);
gumbi.add(stop);
gumbi.add(spust);
gumbi.add(postavi2);
gumbi.add(odvzemi2);
gumbi.add(postavi5);
gumbi.add(odvzemi5);
f.getContentPane();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.add(new staticnaGrafika());
f.pack();
f.setVisible(true);
}
推荐答案
你永远不应该叫睡觉UI线程上的（）相反，我强烈建议您使用javax.swing.Timer和ActionListener。类似于：
You should never be calling sleep() on the UI thread. Instead, I highly recommend that you use javax.swing.Timer and an ActionListener. Something like:
void paintCar(Graphics2D g2d, int x) {
g2d.setColor(Color.blue);
g2d.fillRect(x+10, 351, 118, 23);
g2d.fillRect(x+12, 321, 30, 40);
g2d.fillRect(x+45, 330, 83, 20);
g2d.setColor(Color.black);
g2d.fillOval(x+19, 362, 20, 20);
g2d.fillOval(x+90, 362, 20, 20);
g2d.drawString("2t", x+70, 344);
}
int x = 0;
public MyConstructor() {
new Timer(5, this).start();
}
public void actionPerformed(ActionEvent ae) {
x++;
repaint();
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g;
paintCar(g2d, x);
}
这篇关于重绘/刷新JFrame的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！