我正在构建一个PongClone,但我遇到了一个bug。 **我认为该错误是由JPanel引起的。
我试过Image而不是BufferedImage。我在paintComponent方法之外尝试了drawImage。我创建到另一个面板,然后在主面板中添加该面板。
菜单类
package me.pong;
import javax.swing.*;
public class TestMenu {
JFrame frame;
public void createFrame () {
TestMain main = new TestMain ();
frame = new JFrame("TEST");
frame.setSize (800, 450);
frame.setDefaultCloseOperation (JFrame.EXIT_ON_CLOSE);
frame.getContentPane ().add (main.panel);
frame.setVisible (true);
}
}
MainClass
package me.pong;
import javax.swing.*;
import java.awt.*;
import java.awt.image.BufferedImage;
public class TestMain extends JPanel {
JPanel panel = new JPanel ();
BufferedImage img;
Graphics g;
public static void main (String[] args) {
TestMain testMain = new TestMain ();
TestMenu menu = new TestMenu ();
menu.createFrame ();
testMain.drawGraphics ();
}
public void drawGraphics(){
panel.add (new TestMain ());
img = new BufferedImage(800, 450, BufferedImage.TYPE_INT_RGB);
g = img.createGraphics ();
g.drawString ("TEST STRING 2", 250,250);
}
@Override
protected void paintComponent (Graphics g) {
super.paintComponent (g);
g.clearRect (0,0,800,450);
g.drawImage (img, 0,0,null);
g.setColor (Color.white);
g.drawString ("TEST STRING", 500,250);
g.setColor (Color.black);
g.drawRect (150,100,10,70);
}
}
我希望Image填充组件,但实际输出是小盒子。 Just like that
编辑:删除代码并添加MCVE / SSCCE代码(我不知道)。还是一样的。如果我在框架内添加图像,它可以工作,但其他方式则不然。我知道我错过了什么,但我不知道那是什么。
**是。由JPanel引起的问题,但我不知道如何解决它。
在自定义绘制类中作为面板声明的额外面板不仅是不必要的,而且是问题的根源。请参阅代码中的进一步注释
import javax.swing.*;
import java.awt.*;
import java.awt.image.BufferedImage;
public class TestMain extends JPanel {
JFrame frame;
// Not needed or useful!
//JPanel panel = new JPanel();
BufferedImage img;
Graphics g;
public static void main(String[] args) {
TestMain testMain = new TestMain();
testMain.createFrame();
testMain.drawGraphics();
}
public void createFrame() {
TestMain main = new TestMain();
frame = new JFrame("TEST");
frame.setSize(400, 250);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//frame.getContentPane().add(main.panel);
frame.getContentPane().add(main);
frame.setVisible(true);
}
public void drawGraphics() {
//panel.add(new TestMain());
add(new TestMain());
img = new BufferedImage(800, 450, BufferedImage.TYPE_INT_RGB);
g = img.createGraphics();
g.drawString("TEST STRING 2", 250, 250);
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.clearRect(0, 0, 800, 450);
// all JComponent instances are image observers
//g.drawImage(img, 0, 0, null);
g.drawImage(img, 0, 0, this);
g.setColor(Color.WHITE);
// NEW! Otherwise invisible
g.setColor(Color.RED);
g.drawString("TEST STRING", 200, 100);
g.setColor(Color.BLACK);
g.drawRect(150, 100, 10, 70);
}
}
作为旁白:
BufferedImage
最简单的方法是通过JLabel
在ImageIcon
中显示它。