lin*_*ite 4 java swing paintcomponent
import java.awt.*;
import java.awt.event.*;
import java.util.*;
import javax.swing.*;
public class Circle extends JPanel {
private final ArrayList<Point> point = new ArrayList<>();
public Circle() {
addMouseListener(new MouseAdapter() {
public void mousePressed(MouseEvent event) {
point.add(event.getPoint());
repaint();
}
});
addMouseMotionListener(new MouseMotionAdapter() {
public void mouseDragged(MouseEvent event) {
point.add(event.getPoint());
repaint();
}
});
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(new Color(0, 0, 128));
for (Point p : point)
g.fillOval(p.x, p.y, 15, 15);
}
public static void main(String[] args) {
JFrame f = new JFrame();
f.add(new Circle());
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setSize(800, 600);
f.setVisible(true);
}
}
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这是示例程序.
绘制它显示丑陋的差距:

我看了很多关于java paint的教程,但每次他们的解释都像上面的示例程序一样.Java如何像Microsoft Paint一样制作流畅的笔刷样式?
您需要在每个点之间绘制线而不是椭圆.这是一个稍微修改过的paintComponent方法:
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
g2.setColor(new Color(0, 0, 128));
g2.setStroke(new BasicStroke(15f,
BasicStroke.CAP_ROUND,
BasicStroke.JOIN_ROUND));
for (int i = 1; i < point.size(); i++)
g2.draw(new Line2D.Float(point.get(i-1), point.get(i)));
}
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结果:
