Question

求Java 实现绘制图形并移动代码

在屏幕上绘制一个黑色正方形，当用户按确定键时，此正方形随机向一方向持续移动，且当正方形碰撞到屏幕边缘时向反方向移动。当用户再次按确定键时正方形停止移动。（两个类实现，MIDlet类和普通类）

Answer 1

代码如下：import javax.microedition.lcdui.Canvas;
import javax.microedition.lcdui.Display;
import javax.microedition.lcdui.Graphics;
import javax.microedition.midlet.MIDlet;
import javax.microedition.midlet.MIDletStateChangeException;public class Zfx extends MIDlet {
private Display display;
public Zfx() {
display=Display.getDisplay(this);
Zfxc qs=new Zfxc();
display.setCurrent(qs);
}
protected void destroyApp(boolean arg0) throws MIDletStateChangeException {
}
protected void pauseApp() {
}
protected void startApp() throws MIDletStateChangeException {
}
}
class Zfxc extends Canvas implements Runnable{
private int x,y,x1,y1,i;
private boolean flag;
Zfxc(){
init();
}
private void init(){
Thread thread=new Thread(this);
thread.start();
}
protected void paint(Graphics g) {
g.setColor(255,255,255);
g.fillRect(0, 0, this.getWidth(), this.getHeight());
g.setColor(0);
g.fillRect(x, y, 10, 10);
}
private void logic(){
if(x<=0){
x1=1;
}else if(x>=this.getWidth()-10){
x1=2;
}
if(x1==1){
x+=3;
}else if(x1==2){
x-=3;
}
if(y<=0){
y1=1;
}else if(y>=this.getHeight()-10){
y1=2;
}
if(y1==1){
y+=3;
}else if(y1==2){
y-=3;
}
}
protected void keyPressed(int keyCode) {
if(keyCode==-5){
if(i==0){
flag=true;
i=1;
}else if(i==1){
flag=false;
i=0;
}
}
}
public void run() {
while(true){
if(flag){
logic();
}
repaint();
try {
Thread.sleep(80);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}