我正在做一个项目，我需要一些帮助来画我正在画的圆圈以响应我的计时器。我想使用插入的滑块使它们变慢和变快。随附的代码如下。 （我知道我的代码将是一团糟，我正在使用教授提供的一些源代码来在屏幕上显示滑块。我很难让滑块/定时器与我的圈子聊天。）
import java.util.ArrayList;
import java.util.Random;
import java.awt.*;
import java.awt.event.*;
import javax.swing. *;
import javax.swing.event.*;
import SpeedControlPanel.SlideListener;
public class DotsPanel extends JPanel
{
private final int SIZE = 6; // radius of each dot
private static final long serialVersionUID = 1L;
private ArrayList<Point> pointList;
private Timer timer;
private JLabel lLabel;
private JSlider sSlider;
private JPanel pPanel;
private Circle bouncingBall;
int sSliderHt;
private int moveX, moveY;
AnimationListener animationList;
//-----------------------------------------------------------------
// Constructor: Sets up this panel to listen for mouse events.
//-----------------------------------------------------------------
public DotsPanel()
{
timer = new Timer(30, new AnimationListener());
this.setLayout(new BorderLayout());
bouncingBall = new Circle(SIZE);
Random rand = new Random();
pointList = new ArrayList<Point>();
addMouseListener (new DotsListener());
addMouseMotionListener( new DotsListener());
setBackground(Color.black);
setPreferredSize(new Dimension(500, 300));
lLabel= new JLabel("Timer Delay");
lLabel.setAlignmentX(Component.LEFT_ALIGNMENT);
sSlider = new JSlider(JSlider.HORIZONTAL, 0, 200, 30);
sSlider.setMajorTickSpacing(40);
sSlider.setMinorTickSpacing(10);
sSlider.setPaintTicks(true);
sSlider.setPaintLabels(true);
sSlider.setAlignmentX(Component.LEFT_ALIGNMENT);
sSlider.addChangeListener(new SlideListener());
pPanel= new JPanel();
pPanel.add(lLabel);
pPanel.add(sSlider);
add(pPanel, BorderLayout.SOUTH);
animationList = new AnimationListener();
animationList.timer.start();
/*int[] xArray = new int[1000];
int[] yArray = new int[1000];
for(int i = 0; i < xArray.length; i++)
{
xArray[i] = rand.nextInt(10) + 1;
yArray[i] = rand.nextInt(10) + 1;
}*/
}
//-----------------------------------------------------------------
// Draws all of the dots stored in the list.
//-----------------------------------------------------------------
public void paintComponent(Graphics page)
{
Random rand = new Random();
int R = rand.nextInt(256);
int G = rand.nextInt(256);
int B = rand.nextInt(256);
super.paintComponent(page);
page.setColor(new Color(R%255, (G*3)%255, (B+128)%255));
for (Point spot : pointList)
//page.fillOval(spot.x-SIZE, spot.y-SIZE, SIZE*2, SIZE*2);
page.fillOval(spot.x, spot.y, SIZE*2, SIZE*2);
page.drawString("Count: " + pointList.size(), 5, 15);
}
private class AnimationListener implements ActionListener {
int xRand[];
int yRand[];
Random rand;
public AnimationListener() {
rand = new Random();
xRand = new int[1000];
yRand = new int[1000];
//Filling random values between 0 to 10
for (int i = 0; i < 1000; i++) {
xRand[i] = rand.nextInt(10) + 1;
yRand[i] = rand.nextInt(10) + 1;
}
}
private Timer timer = new Timer(50, this);
@Override
public void actionPerformed(ActionEvent e) {
//Put here for the bounce off of the wall
Rectangle window = getBounds();
for (int i = 0; i < pointList.size(); i++) {
Point spot = pointList.get(i);
spot.x += xRand[i];
spot.y += yRand[i];
if (spot.x <= 0) {
xRand[i] = Math.abs(xRand[i]);
} else if (spot.x >= window.width - (SIZE*2)) {
xRand[i] = -Math.abs(xRand[i]);
}
if (spot.y <= 0) {
yRand[i] = Math.abs(yRand[i]);
} else if (spot.y >= window.height - (SIZE*2)) {
yRand[i] = -Math.abs(yRand[i]);
}
}
bouncingBall.move(moveX, moveY);
// change direction if ball hits a side
int x = bouncingBall.getX();
int y = bouncingBall.getY();
if (x < 0 || x >= WIDTH - SIZE)
{
moveX = moveX * -1;
}
if (y <= 0 || y >= HEIGHT - SIZE)
{
moveY = moveY * -1;
}
sSliderHt =sSlider.getSize().height;
repaint();
repaint();
}
}
//*****************************************************************
// Represents the listener for mouse events.
//*****************************************************************
private class DotsListener implements MouseListener, MouseMotionListener
{
//--------------------------------------------------------------
// Adds the current point to the list of points and redraws
// the panel whenever the mouse button is pressed.
//--------------------------------------------------------------
public void mousePressed(MouseEvent event)
{
pointList.add(event.getPoint());
repaint();
}
public void mouseDragged(MouseEvent event) {
pointList.add(event.getPoint());
repaint();
}
//--------------------------------------------------------------
// Provide empty definitions for unused event methods.
//--------------------------------------------------------------
public void mouseClicked(MouseEvent event) {}
public void mouseReleased(MouseEvent event) {}
public void mouseEntered(MouseEvent event) {}
public void mouseExited(MouseEvent event) {}
}
private class SlideListener implements ChangeListener
{
// ------------------------------------------------
// Called when the state of the slider has changed;
// resets the delay on the timer.
// ------------------------------------------------
public void stateChanged (ChangeEvent event)
{
//int sSliderHt =sSlider.getSize().height;
timer.setDelay(sSlider.getValue());
}
}
}
我想使用插入的滑块使它们变慢和变快。
因此，在我看来，您已经具有使每次计时器启动时每个圆圈移动随机距离的逻辑。
因此，只需使用滑块即可更改计时器触发的时间间隔。然后，每当计时器触发时，您便会根据您的随机距离设置新的圆圈位置。
其他问题：
paintComponent（...）方法仅用于绘画。它不应设置类的属性。例如，您不应在该方法中生成随机值。您无法控制何时调用paintComponent（）并且不想随意更改要绘制的对象的属性。
不要使用数组来保存随机值。首先，您不知道要添加多少个对象，因此您不想设置大小限制。而是使用ArrayList。
创建一个自定义对象以包含要控制的所有属性。这样，您就可以在自定义对象中绘制每个圆圈的大小/位置/颜色等。
有关使用上述建议的示例，请参见：get width and height of JPanel outside of the class。