基于按键旋转图像 [英] Rotating an image based on key presses

问题描述

我试图修改现有代码以基于按键旋转图像.到目前为止，我已经做到了以下几点，但我陷入了困境.我第一次使用了仿射变换.当图像应按按RIGHT键的次数旋转时，图像仅旋转一次.

I was trying to modify an existing code to rotate an image based on key presses. so far i've managed to do the following and I'm stuck. i've made use of Affine transform for the first time. The image rotates only once when it's supposed to rotate as many times as the RIGHT key is pressed.

package aircraftPackage;

import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.MediaTracker;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.JFrame;

public class RotateImage extends JFrame implements KeyListener {
    private static final long serialVersionUID = 1L;
    private Image TestImage;
    private BufferedImage bf;
    private int cordX = 100;
    private int cordY = 100;
    private double currentAngle;

    public RotateImage(Image TestImage) {
     this.TestImage = TestImage;
     MediaTracker mt = new MediaTracker(this);
     mt.addImage(TestImage, 0);
     try {
       mt.waitForID(0);
     }
     catch (Exception e) {
       e.printStackTrace();
     }
        setTitle("Testing....");
        setSize(500, 500);
        imageLoader();
        setVisible(true);
    }
public void rotate() {
     //rotate 5 degrees at a time
     currentAngle+=5.0;
     if (currentAngle >= 360.0) {
       currentAngle = 0;
     }
     repaint();
   }


    public void imageLoader() {
        try {
            String testPath = "test.png";
            TestImage = ImageIO.read(getClass().getResourceAsStream(testPath));

        } catch (IOException ex) {
            ex.printStackTrace();
        }

        addKeyListener(this);
    }

    public void update(Graphics g){
           paint(g);
    }

    public void paint(Graphics g){

        bf = new BufferedImage( this.getWidth(),this.getHeight(), BufferedImage.TYPE_INT_RGB);

    try{
    animation(bf.getGraphics());
    g.drawImage(bf,0,0,null);
    }catch(Exception ex){

    }
}

    public void animation(Graphics g) {
        super.paint(g);
        Graphics2D g2d = (Graphics2D)g;
        AffineTransform origXform = g2d.getTransform();
        AffineTransform newXform = (AffineTransform)(origXform.clone());
        //center of rotation is center of the panel
        int xRot = this.getWidth()/2;
        int yRot = this.getHeight()/2;
        newXform.rotate(Math.toRadians(currentAngle), xRot, yRot);
        g2d.setTransform(newXform);
        //draw image centered in panel
        int x = (getWidth() - TestImage.getWidth(this))/2;
        int y = (getHeight() - TestImage.getHeight(this))/2;
        g2d.drawImage(TestImage, x, y, this);
        g2d.setTransform(origXform);
        g.drawImage(TestImage, cordX, cordY, this);
    }

    public static void main(String[] args) {

        new RotateImage(null);
    }

    public void keyPressed(KeyEvent ke) {
            final RotateImage ri = new RotateImage(TestImage);

        switch (ke.getKeyCode()) {
        case KeyEvent.VK_RIGHT: {
            cordX += 5;

           ri.rotate();
        }
            break;
        case KeyEvent.VK_LEFT: {
            cordX -= 5;
        }
            break;
        case KeyEvent.VK_DOWN: {
            cordY += 5;
        }
            break;
        case KeyEvent.VK_UP: {
            cordY -= 3;
        }
            break;
        }
        repaint();
    }

    public void keyTyped(KeyEvent ke) {
    }

    public void keyReleased(KeyEvent ke) {
    }
}

如果有人可以纠正我犯错的地方，这将是有帮助的. 谢谢

would be helpful if anyone could correct me on where im making the mistake. Thanks

推荐答案

您正在每个事件键上创建新的旋转图像的问题，因此好像无法正常工作 尝试将此行的位置更改为每个关键事件均不可修改

the problem you are creating new rotate image on each event key so it looks like not working try to change the place of this line to be none modifiable on each key event

public static void main(String[] args) {

        new RotateImage(null);
    }

    public void keyPressed(KeyEvent ke) {
            final RotateImage ri = new RotateImage(TestImage);

更新:

原因是因为构造函数的值为null，所以您应该传递图像

the reason is because the value of constructor is null you should pass image

new RotateImage(null);

在您的代码上修改

1)将其设为静态

private static Image TestImage;

2)定义

private static RotateImage ri;

3)像这样调用main

3)call in main like this

public static void main(String[] args) {
         ri = new RotateImage(TestImage);
    }

第4步(已删除)

更新:

在堆栈溢出时阅读这些问题 另一个问题

UPDATE2:

这是可以正常工作的完整代码(向右键)，不要将图像包含在同一包中，并且其类型相同..png这是代码

here is the full code it works perfectly ( the right key ) dont foget to include you image in the same package and its the same type .png here is the code

package aircraftPackage;

import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.MediaTracker;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.JFrame;

public class RotateImage extends JFrame implements KeyListener {
    private static final long serialVersionUID = 1L;
    private static Image TestImage;
    private static RotateImage ri;
    private BufferedImage bf;
    private int cordX = 100;
    private int cordY = 100;
    private double currentAngle;

    public RotateImage(Image TestImage) {
     this.TestImage = TestImage;
     MediaTracker mt = new MediaTracker(this);
     mt.addImage(TestImage, 0);
     try {
       mt.waitForID(0);
     }
     catch (Exception e) {
       e.printStackTrace();
     }
        setTitle("Testing....");
        setSize(500, 500);
        imageLoader();
        setVisible(true);
    }
public void rotate() {
     //rotate 5 degrees at a time
     currentAngle+=5.0;
     if (currentAngle >= 360.0) {
       currentAngle = 0;
     }
     repaint();
   }


    public void imageLoader() {
        try {
            String testPath = "test.png";
            TestImage = ImageIO.read(getClass().getResourceAsStream(testPath));

        } catch (IOException ex) {
            ex.printStackTrace();
        }

        addKeyListener(this);
    }

    public void update(Graphics g){
           paint(g);
    }

    public void paint(Graphics g){

        bf = new BufferedImage( this.getWidth(),this.getHeight(), BufferedImage.TYPE_INT_RGB);

    try{
    animation(bf.getGraphics());
    g.drawImage(bf,0,0,null);
    }catch(Exception ex){

    }
}

    public void animation(Graphics g) {
        super.paint(g);
        Graphics2D g2d = (Graphics2D)g;
        AffineTransform origXform = g2d.getTransform();
        AffineTransform newXform = (AffineTransform)(origXform.clone());
        //center of rotation is center of the panel
        int xRot = this.getWidth()/2;
        int yRot = this.getHeight()/2;
        newXform.rotate(Math.toRadians(currentAngle), xRot, yRot);
        g2d.setTransform(newXform);
        //draw image centered in panel
        int x = (getWidth() - TestImage.getWidth(this))/2;
        int y = (getHeight() - TestImage.getHeight(this))/2;
        g2d.drawImage(TestImage, x, y, this);
        g2d.setTransform(origXform);
        g.drawImage(TestImage, cordX, cordY, this);
    }

    public static void main(String[] args) {
         ri = new RotateImage(TestImage);

    }

    public void keyPressed(KeyEvent ke) {

        switch (ke.getKeyCode()) {
        case KeyEvent.VK_RIGHT: {
            cordX += 5;

           ri.rotate();
        }
            break;
        case KeyEvent.VK_LEFT: {
            cordX -= 5;
            ri.rotate();
        }
            break;
        case KeyEvent.VK_DOWN: {
            cordY += 5;
            ri.rotate();
        }
            break;
        case KeyEvent.VK_UP: {
            cordY -= 3;
            ri.rotate();
        }
            break;
        }
        repaint();
    }

    public void keyTyped(KeyEvent ke) {
    }

    public void keyReleased(KeyEvent ke) {
    }
}

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