我正忙于摆弄 Java 的 Graphics2D 和绘图，虽然它可以工作，但我不确定如何从该图形创建 BufferedImage，我似乎需要这样做才能将其保存在某个地方。
我有一些非常基础的东西，因为我想了解它是如何工作的
import javax.swing.*;
import javax.imageio.*;
import java.awt.*;
import java.awt.image.*;
import java.io.*;
public class myFrame {
public static void main(String[] args) {
JFrame lv_frame = new JFrame();
lv_frame.setTitle("Drawing");
lv_frame.setSize(300, 300);
lv_frame.setDefaultCloseOperation(JInternalFrame.DISPOSE_ON_CLOSE);
lv_frame.add(new drawingPanel(5, 5));
lv_frame.setVisible(true);
}
}
class drawingPanel extends JPanel {
public drawingPanel(int x, int y) {
}
public void draw(Graphics graphic) {
Graphics2D graphic2D = (Graphics2D) graphic;
graphic2D.fillArc(0, 0, 50, 50, 0, 45);
graphic2D.fillArc(0, 0, 50, 50, 135, 45);
BufferedImage image = new BufferedImage(100, 100, BufferedImage.TYPE_INT_BGR);
try {
graphic2D = image.createGraphics();
File output = new File("output.png");
ImageIO.write(image, "png", output);
} catch(IOException log) {
System.out.println(log);
}
}
public void paintComponent(Graphics graphic) {
super.paintComponent(graphic);
draw(graphic);
}
}
这工作正常，除了我得到一个空白的 png 作为我的 output.png 并且我不确定为什么虽然我很确定我的代码是非常错误的
工作版本
import javax.swing.*;
import javax.imageio.*;
import java.awt.*;
import java.awt.image.*;
import java.io.*;
public class myFrame {
public static void main(String[] args) {
JFrame lv_frame = new JFrame();
lv_frame.setTitle("Drawing");
lv_frame.setSize(300, 300);
lv_frame.setDefaultCloseOperation(JInternalFrame.DISPOSE_ON_CLOSE);
lv_frame.add(new drawingPanel());
lv_frame.setVisible(true);
}
}
class drawingPanel extends JPanel {
public void paintComponent(Graphics graphic) {
super.paintComponent(graphic);
draw(graphic);
saveImage();
}
public void draw(Graphics graphic) {
Graphics2D graphic2D = (Graphics2D) graphic;
Color color = Color.decode("#DDDDDD");
graphic2D.setPaint(color);
graphic2D.fillArc(0, 0, 50, 50, 0, 45);
graphic2D.fillArc(0, 0, 50, 50, 135, 45);
}
public void saveImage() {
BufferedImage image = new BufferedImage(100, 100, BufferedImage.TYPE_INT_BGR);
Graphics2D graphic2D = image.createGraphics();
try {
File output = new File("output.png");
draw(graphic2D);
ImageIO.write(image, "png", output);
} catch(IOException log) {
System.out.println(log);
}
}
}
最佳答案
您正在用从 image.createGraphics() 获得的对象覆盖 Graphics2D 对象，它在您刚创建时是空白的。
将 draw 方法简化为:
public void draw(Graphics graphic) {
Graphics2D graphic2D = (Graphics2D) graphic;
graphic2D.fillArc(0, 0, 50, 50, 0, 45);
graphic2D.fillArc(0, 0, 50, 50, 135, 45);
}
然后从另一个方法调用它，在您实际的 Image 的 Graphics2D 上执行绘画:
public void saveAsImage(){
BufferedImage image = new BufferedImage(100, 100, BufferedImage.TYPE_INT_BGR);
try {
Graphics2D graphic = image.createGraphics();
File output = new File("output.png");
draw(graphic); // actual drawing on your image
ImageIO.write(image, "png", output);
} catch(IOException log) {
System.out.println(log);
}
}
关于Java Graphics2D 绘图到 BufferedImage，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/35507152/