Java:图形二维
Java: Graphics2D
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
public class SimpleGui3C implements ActionListener {
JFrame frame;
public static void main(String[] args) {
SimpleGui3C gui = new SimpleGui3C();
gui.go();
}
public void go() {
frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JButton button = new JButton("Change Colors");
button.addActionListener(this);
MyDrawPanel drawPanel = new MyDrawPanel();
frame.getContentPane().add(BorderLayout.SOUTH, button);
frame.getContentPane().add(BorderLayout.CENTER, drawPanel);
frame.setSize(300, 300);
frame.setVisible(true);
}
public void actionPerformed(ActionEvent event) {
frame.repaint();
}
}
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
class MyDrawPanel extends JPanel {
public void paintComponet(Graphics g) {
Graphics2D g2d = (Graphics2D) g;
int red = (int) (Math.random() * 256);
int green = (int) (Math.random() * 256);
int blue = (int) (Math.random() * 256);
Color startColor = new Color(red, green, blue);
red = (int) (Math.random() * 256);
green = (int) (Math.random() * 256);
blue = (int) (Math.random() * 256);
Color endColor = new Color(red, green, blue);
GradientPaint gradient = new GradientPaint(70, 70, startColor, 150, 150, endColor);
g2d.setPaint(gradient);
g2d.fillOval(70, 70, 100, 100);
}
}
所以我一直试图连续2个小时解决这个问题,但似乎无法解决问题。这个 "program" 应该有一个椭圆形,屏幕底部出现一个按钮,允许我使用 netbeans 随机化 oval.I 的颜色,每当我点击 运行 我得到这个:
有人能解决我的问题吗?如果这是一个愚蠢的问题,很抱歉浪费你的时间。
拼写很重要:paintComponet != paintComponent
始终在重写方法前加上 @Override
。如果你这样做了,编译器会警告你错误。
所以改变这个:
public void paintComponet(Graphics g) {
Graphics2D g2d = (Graphics2D) g;
int red = (int) (Math.random() * 256);
int green = (int) (Math.random() * 256);
int blue = (int) (Math.random() * 256);
Color startColor = new Color(red, green, blue);
red = (int) (Math.random() * 256);
green = (int) (Math.random() * 256);
blue = (int) (Math.random() * 256);
Color endColor = new Color(red, green, blue);
GradientPaint gradient = new GradientPaint(70, 70, startColor, 150, 150, endColor);
g2d.setPaint(gradient);
g2d.fillOval(70, 70, 100, 100);
}
对此:
@Override // don't forget this
protected void paintComponent(Graphics g) { // spelling matters. Also make it protected
// !!!! don't forget this!
super.paintComponent(g); // to have the JPanel do housekeeping painting
Graphics2D g2d = (Graphics2D) g;
int red = (int) (Math.random() * 256);
int green = (int) (Math.random() * 256);
int blue = (int) (Math.random() * 256);
Color startColor = new Color(red, green, blue);
red = (int) (Math.random() * 256);
green = (int) (Math.random() * 256);
blue = (int) (Math.random() * 256);
Color endColor = new Color(red, green, blue);
GradientPaint gradient = new GradientPaint(70, 70, startColor, 150, 150, endColor);
g2d.setPaint(gradient);
g2d.fillOval(70, 70, 100, 100);
}
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
public class SimpleGui3C implements ActionListener {
JFrame frame;
public static void main(String[] args) {
SimpleGui3C gui = new SimpleGui3C();
gui.go();
}
public void go() {
frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JButton button = new JButton("Change Colors");
button.addActionListener(this);
MyDrawPanel drawPanel = new MyDrawPanel();
frame.getContentPane().add(BorderLayout.SOUTH, button);
frame.getContentPane().add(BorderLayout.CENTER, drawPanel);
frame.setSize(300, 300);
frame.setVisible(true);
}
public void actionPerformed(ActionEvent event) {
frame.repaint();
}
}
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
class MyDrawPanel extends JPanel {
public void paintComponet(Graphics g) {
Graphics2D g2d = (Graphics2D) g;
int red = (int) (Math.random() * 256);
int green = (int) (Math.random() * 256);
int blue = (int) (Math.random() * 256);
Color startColor = new Color(red, green, blue);
red = (int) (Math.random() * 256);
green = (int) (Math.random() * 256);
blue = (int) (Math.random() * 256);
Color endColor = new Color(red, green, blue);
GradientPaint gradient = new GradientPaint(70, 70, startColor, 150, 150, endColor);
g2d.setPaint(gradient);
g2d.fillOval(70, 70, 100, 100);
}
}
所以我一直试图连续2个小时解决这个问题,但似乎无法解决问题。这个 "program" 应该有一个椭圆形,屏幕底部出现一个按钮,允许我使用 netbeans 随机化 oval.I 的颜色,每当我点击 运行 我得到这个:
拼写很重要:paintComponet != paintComponent
始终在重写方法前加上 @Override
。如果你这样做了,编译器会警告你错误。
所以改变这个:
public void paintComponet(Graphics g) {
Graphics2D g2d = (Graphics2D) g;
int red = (int) (Math.random() * 256);
int green = (int) (Math.random() * 256);
int blue = (int) (Math.random() * 256);
Color startColor = new Color(red, green, blue);
red = (int) (Math.random() * 256);
green = (int) (Math.random() * 256);
blue = (int) (Math.random() * 256);
Color endColor = new Color(red, green, blue);
GradientPaint gradient = new GradientPaint(70, 70, startColor, 150, 150, endColor);
g2d.setPaint(gradient);
g2d.fillOval(70, 70, 100, 100);
}
对此:
@Override // don't forget this
protected void paintComponent(Graphics g) { // spelling matters. Also make it protected
// !!!! don't forget this!
super.paintComponent(g); // to have the JPanel do housekeeping painting
Graphics2D g2d = (Graphics2D) g;
int red = (int) (Math.random() * 256);
int green = (int) (Math.random() * 256);
int blue = (int) (Math.random() * 256);
Color startColor = new Color(red, green, blue);
red = (int) (Math.random() * 256);
green = (int) (Math.random() * 256);
blue = (int) (Math.random() * 256);
Color endColor = new Color(red, green, blue);
GradientPaint gradient = new GradientPaint(70, 70, startColor, 150, 150, endColor);
g2d.setPaint(gradient);
g2d.fillOval(70, 70, 100, 100);
}