我试图用按钮移动形状，但我没有得到它。这是我的抽奖课
class MyCanvas extends JComponent {
public void paint(Graphics g) {
g.setColor(Color.RED);
g.fill3DRect(20, 20, 200, 200,true);
}
}
class MyCanvas1 extends JComponent {
public void paint(Graphics g) {
g.setColor(Color.RED);
g.drawRect(20, 20, 200, 200);
}
}
我通过以下代码成功绘图 - ＆gt;
public class ButtonListener implements ActionListener
{
public void actionPerformed(ActionEvent e) {
if(check)
{
if(e.getSource()==btnNewButton)
{
MyCanvas can=new MyCanvas();
me s=new me();
can.setSize(400, 500);
panel_3.add(can);
panel_3.repaint();
addComponent(can);
s.can;
choice=true;
}
}
else
{
if(e.getSource()==btnNewButton)
{
panel_3.removeAll();
MyCanvas1 can=new MyCanvas1();
can.setSize(500, 500);
panel_3.add(can);
panel_3.repaint();
addComponent(can);
}
}
它对我来说很好。现在我有另外4个按钮，我想通过点击按钮移动形状。我尝试了一些方法，但没有一个能为我工作。任何建议我怎么做。我应该创建任何新的动作事件或类。
答案 0 :(得分：2)
了解绘画如何在Swing中发挥作用，请参阅Painting in AWT and Swing和Performing Custom Painting。
建议您覆盖paintComponent而不是paint并始终确保拨打super.paintComponent
public class MyCanvas extends JComponent {
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(Color.RED);
g.fill3DRect(20, 20, 200, 200,true);
}
}
有很多方法可以实现这一点，就个人而言，我只是使用Graphics2D and Shapes APIs，但有些事情告诉我，对你来说不够好，所以。 ..
不是试图使用基于组件的形状（并且必须与布局管理器对抗），而是创建一个描述＆＃34; drawable＆＃34;元素，可以画的东西......
public interface Drawable {
public Rectangle getBounds();
public void setBounds(Rectangle bounds);
public Color getColor();
public void setColor(Color color);
public void draw(Graphics2D g2d);
}
这描述了可以绘制的内容，颜色在哪里以及颜色
接下来，维护List个Drawables并使用paintComponent方法绘制它们......
public class MyCanvas extends JComponent {
private List<Drawable> drawables;
public MyCanvas() {
drawables = new ArrayList<>(25);
}
public Dimension getPreferredSize() {
return new Dimension(400, 400);
}
public void add(Drawable drawable) {
drawables.add(drawable);
repaint();
}
public void remove(Drawable drawable) {
drawables.remove(drawable);
repaint();
}
public int getDrawableCount() {
return drawables.size();
}
public Drawable getDrawableAt(int index) {
return drawables.get(index);
}
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D)g.create();
for (Drawable d : drawables) {
d.draw(g2d);
}
g2d.dispose();
}
}
现在你有一些可以画画的东西和可以画它们的东西......
制作一些东西。我从一个抽象的Drawable开始，它涵盖了所有常见的东西，让生活更轻松......
public abstract class AbstractDrawable {
private Rectangle bounds;
private Color color
public AbstractDrawable(Rectangle bounds, Color color) {
setBounds(bounds);
setColor(color);
}
public Rectangle getBounds() {
return bounds;
}
public void setBounds(Dimension bounds) {
this.bounds = bounds;
}
public Color getColor() {
return color;
}
public void setColor(Color color) {
this.color = color;
}
public abstract void draw(Graphics2D g2d);
}
你可以疯了......
public class DrawableRectangle {
public AbstractDrawable(Rectangle bounds, Color color) {
super(bounds, color);
}
public abstract void draw(Graphics2D g2d) {
g2d.setColor(getColor());
g2d.fill(getBounds());
}
}
和/或...
public class Drawable3DRectangle {
public AbstractDrawable(Rectangle bounds, Color color) {
super(bounds, color);
}
public abstract void draw(Graphics2D g2d) {
g2d.setColor(getColor());
Rectangle bounds = getBounds();
g2d.fill3DRect(bounds.x, bounds.y, bounds.width, bounds.height);
}
}
把它们放在一起......
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class DrawableShapes {
public static void main(String[] args) {
new DrawableShapes();
}
public DrawableShapes() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private MyCanvas canvas;
public TestPane() {
setLayout(new BorderLayout());
canvas = new MyCanvas();
add(canvas);
canvas.add(new Drawable3DRectangle(new Rectangle(20, 20, 100, 100), Color.RED));
canvas.add(new DrawableRectangle(new Rectangle(20, 140, 100, 100), Color.RED));
}
}
}
好的，所以这画了两个drawables，但是如何移动它们？
基本上，您获取对要移动的Drawable的引用，例如......
Drawable drawable = canvas.getDrawableAt(0);
然后你修改它的位置......
drawable.getBounds().x += 5;
drawable.getBounds().y += 5;
然后重新绘制MyCanvas实例...
canvas.repaint();
答案 1 :(得分：0)
我为你写了一个快速代码来获取这个想法 您可以使用Component setLocation（int x，int y）来完成此操作;获取当前x和y位置可以使用JComponent getX（）和getY（）方法。
例如comp.setLocation（comp.getX（），comp.getY（））;
public class Move extends JFrame implements ActionListener {
JComponent b = new JButton("Move me");
JButton a = new JButton("Move that");
Random rd = new Random();
public Move() throws HeadlessException {
setLayout(new FlowLayout());
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
add(a);
add(b);
a.addActionListener(this);
setVisible(true);
}
@Override
public void actionPerformed(ActionEvent e) {
repaint();
}
public static void main(String[] args) {
new Move();
}
@Override
public void paint(Graphics g) {
super.paint(g);
int r = rd.nextInt(400);
b.setLocation(b.getX(), r);
}
}