我正在尝试将一个对象(在本例中为蓝色圆圈)从一个位置移动到另一个位置。这将位于 8*8 网格上。
gBoard.setColor(Color.LIGHT_GRAY);
gBoard.fillRect(0,0,400,400);
for (int k=000; k<=300; k+=100){
for (int l=000; l<=300; l+=100){
gBoard.clearRect(k,l,50,50);
}
}
for (int k=50; k<=350; k+=100){
for (int l=50; l<=350; l+=100){
gBoard.clearRect(k,l,50,50);
}
}
上面的代码显示我已经成功创建了 8*8 网格，这意味着我可以将对象放置在需要的位置。
gBoard.setColor(Color.BLUE);
int x = 0;
int y = 0;
gBoard.fillOval(x,y,50,50);
上面的代码显示我已将对象放入网格中，但是这会进入 public void 方法还是一个单独的方法，因为该对象不会处于常量地点。该物体会不断移动。 public void 更合适还是最好为接口(interface)使用单独的方法？
最佳答案
建议:
- 使用 GridLayout 创建添加到 JPanel 的 JLabel 网格
- 使用采用 Icon 的 JLabel 构造函数为每个 JLabel 提供一个适当大小的空 ImageIcon。
- 同时创建另一个包含彩色磁盘的 ImageIcon
- 通过在 JLabel 上调用
setIcon(...)将图标移动到相应的 JLabel - 通过调用
setIcon(...)并传入空图标或空白图标，从 JLabel 中删除图标。
例如，
import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.GridLayout;
import java.awt.RenderingHints;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.image.BufferedImage;
import javax.swing.BorderFactory;
import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
@SuppressWarnings("serial")
public class ColoredOvals extends JPanel {
public static final int CELL_WIDTH = 50;
public static final int SIDE = 8;
private JLabel[][] grid = new JLabel[SIDE][SIDE];
private Icon emptyIcon;
private Icon colorIcon;
public ColoredOvals() {
// so lines appear between cells
setBackground(Color.BLACK);
// empty icon is 50x50 in size, and with clear color
emptyIcon = createIcon(new Color(0, 0, 0, 0));
// icon with a RED disk
colorIcon = createIcon(Color.RED);
// create a grid layout to hold the JLabels
// the 1, 1 is for the empty space between cells to show the black line
setLayout(new GridLayout(SIDE, SIDE, 1, 1));
// line around the entire JPanel (if desired)
setBorder(BorderFactory.createLineBorder(Color.BLACK));
// mouse listener that moves the icon to the selected cell:
MouseListener mouseListener = new MouseAdapter() {
@Override
public void mousePressed(MouseEvent e) {
clearGrid(); // all labels hold blank icon
JLabel label = (JLabel) e.getSource();
label.setIcon(colorIcon); // selected JLabel holds disk
}
};
// iterate through the grid 2D array, creating JLabels and adding
// blank icon as well as a MouseListener
for (int i = 0; i < grid.length; i++) {
for (int j = 0; j < grid[i].length; j++) {
grid[i][j] = new JLabel(emptyIcon); // blank icon
grid[i][j].setOpaque(true);
grid[i][j].setBackground(Color.WHITE);
add(grid[i][j]);
grid[i][j].addMouseListener(mouseListener);
}
}
}
public void clearGrid() {
for (JLabel[] jLabels : grid) {
for (JLabel jLabel : jLabels) {
jLabel.setIcon(emptyIcon);
}
}
}
// code to create blank icon or disk icon of color of choice
private Icon createIcon(Color color) {
BufferedImage img = new BufferedImage(CELL_WIDTH, CELL_WIDTH, BufferedImage.TYPE_INT_ARGB);
Graphics2D g2 = img.createGraphics();
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g2.setColor(color);
int gap = 2;
g2.fillOval(gap, gap, CELL_WIDTH - 2 * gap, CELL_WIDTH - 2 * gap);
g2.dispose();
return new ImageIcon(img);
}
private static void createAndShowGui() {
ColoredOvals mainPanel = new ColoredOvals();
JFrame frame = new JFrame("ColoredOvals");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> createAndShowGui());
}
}
选项 2——如果您想要磁盘更加自由的运动，那么:
- 将 MouseListener 和 MouseMotionListener 添加到 JPanel 本身
- 在此组合监听器中(两者均使用 MouseAdapter)，更改两个 int 字段(例如 centerX 和 centerY)保存的值，然后调用
repaint(); - 重写paintComponent方法，注意在重写中调用super的方法
- 在覆盖中，在鼠标监听器更改的字段指定的位置绘制磁盘。
例如:
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
@SuppressWarnings("serial")
public class ColoredOvals2 extends JPanel {
public static final int CELL_WIDTH = 50;
public static final int SIDE = 8;
private static final Color BG = Color.WHITE;
private static final Color DISK_COLOR = Color.BLUE;
private int centerX = 0;
private int centerY = 0;
public ColoredOvals2() {
setBackground(BG);
MouseAdapter myMouse = new MouseAdapter() {
@Override
public void mousePressed(MouseEvent e) {
moveDisk(e);
}
@Override
public void mouseDragged(MouseEvent e) {
moveDisk(e);
}
private void moveDisk(MouseEvent e) {
centerX = e.getX();
centerY = e.getY();
repaint();
}
};
addMouseListener(myMouse);
addMouseMotionListener(myMouse);
}
@Override
public Dimension getPreferredSize() {
if (isPreferredSizeSet()) {
return super.getPreferredSize();
}
int w = SIDE * CELL_WIDTH;
int h = w;
return new Dimension(w, h);
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g2.setColor(DISK_COLOR);
int x = centerX - CELL_WIDTH / 2;
int y = centerY - CELL_WIDTH / 2;
int w = CELL_WIDTH;
int h = CELL_WIDTH;
g2.fillOval(x, y, w, h);
}
private static void createAndShowGui() {
ColoredOvals2 mainPanel = new ColoredOvals2();
JFrame frame = new JFrame("ColoredOvals2");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> createAndShowGui());
}
}
关于java - 如何将对象形状从一个位置移动到另一个位置？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/49834416/