我正在使用keylistener在屏幕上移动图像，并且它可以正常工作。但是，每次我使图像向不同方向移动时，图像会暂停200-500毫秒，然后再向那个方向移动。我想知道这是否正常，如果这只是将键盘输入发送到处理器需要多长时间，以及到达那个方向需要多长时间，或者我是否在代码中做错了。谢谢。
public class Fishy extends Panel implements KeyListener, MouseMotionListener {
int x1;// first x location of the shape.
int x2;// second x location of the shape
int y1;// first y location of the shape
int y2;// second y location of the shape
int shapeWidth;// width of the shape
int shapeHeight;// height of the shape
static final int left = 37;
static final int right = 39;
static final int down = 40;
static final int up = 38;
static boolean leftPress;
static boolean rightPress;
static boolean upPress;
static boolean downPress;
static int speed = 3;
static int x;
static int y;
static int size = 50;
static Image LimageFishy = new ImageIcon("E://Picture//Lfish.png").getImage();
static Image RimageFishy = new ImageIcon("E://Picture//Rfish.png").getImage();
static BufferedImage bufferedImageFishy;
// tatic int wolfWidth = wolf.getWidth(null);
// static int wolfHeight = wolf.getHeight(null);
// TREE method of extending classes[]
static Fishy fishy = new Fishy(500, 500, 9);
Fishy(int width, int length, int minusBy) {
super(width, length, minusBy);
}
/* Graphics goes here */
public void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(Color.BLACK);
g.fillRect(0, 0, 500, 500);
size++;
g.drawImage(RimageFishy, x1, y1, size, 50, null);
g.drawString(DraggingShapes.mousePointerLocation, 50, 50);
}
public static void main(String args[]) throws IOException {
JFrame frame = new JFrame("Fishy");
frame.addKeyListener(fishy);
fishy.addMouseMotionListener(fishy);
fishy.x1 = 50;
fishy.y1 = 50;
// bufferedImageFishy = toBufferedImage(imageFishy);
// System.out.println(bufferedImageFishy.getHeight());
// imageFishy = getScaledInstance(bufferedImageFishy, 50, 50, null, true);
frame.add(fishy);
Frame.showFrame(frame, false);
}
/**************************************************/
public static BufferedImage getScaledInstance(BufferedImage img, int targetWidth, int targetHeight, Object hint, boolean higherQuality) {
int type = (img.getTransparency() == Transparency.OPAQUE) ? BufferedImage.TYPE_INT_RGB : BufferedImage.TYPE_INT_ARGB;
BufferedImage ret = (BufferedImage) img;
int w, h;
if (higherQuality) {
// Use multi-step technique: start with original size, then
// scale down in multiple passes with drawImage()
// until the target size is reached
w = img.getWidth();
h = img.getHeight();
} else {
// Use one-step technique: scale directly from original
// size to target size with a single drawImage() call
w = targetWidth;
h = targetHeight;
}
do {
if (higherQuality && w > targetWidth) {
w /= 2;
if (w < targetWidth) {
w = targetWidth;
}
}
if (higherQuality && h > targetHeight) {
h /= 2;
if (h < targetHeight) {
h = targetHeight;
}
}
BufferedImage tmp = new BufferedImage(w, h, type);
Graphics2D g2 = tmp.createGraphics();
g2.setRenderingHint(RenderingHints.KEY_INTERPOLATION, hint);
g2.drawImage(ret, 0, 0, w, h, null);
g2.dispose();
ret = tmp;
} while (w != targetWidth || h != targetHeight);
return ret;
}
/**************************************************/
public static BufferedImage toBufferedImage(Image img) {
if (img instanceof BufferedImage) {
return (BufferedImage) img;
}
// Create a buffered image with transparency
// img.getWidth(null)
// img.getHeight(null);
BufferedImage bimage = new BufferedImage(50, 50, BufferedImage.TYPE_INT_ARGB);
// Draw the image on to the buffered image
Graphics2D bGr = bimage.createGraphics();
bGr.drawImage(img, 0, 0, null);
bGr.dispose();
// Return the buffered image
return bimage;
}
/**************************************************/
@Override
public void keyPressed(KeyEvent e) {
if (up == e.getKeyCode()) {
upPress = true;
}
if (down == e.getKeyCode()) {
downPress = true;
}
if (left == e.getKeyCode()) {
leftPress = true;
}
if (right == e.getKeyCode()) {
rightPress = true;
}
/* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */
if (upPress == true && leftPress == false && rightPress == false) {
fishy.y1 -= speed;
}
if (downPress == true && leftPress == false && rightPress == false) {
fishy.y1 += speed;
}
if (leftPress == true && upPress == false && downPress == false) {
fishy.x1 -= speed;
}
if (rightPress == true && upPress == false && downPress == false) {
fishy.x1 += speed;
}
/* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */
if (leftPress == true && upPress == true) {
fishy.x1 -= speed;
fishy.y1 -= speed;
}
if (leftPress == true && downPress == true) {
fishy.x1 -= speed;
fishy.y1 += speed;
}
if (rightPress == true && upPress == true) {
fishy.x1 += speed;
fishy.y1 -= speed;
}
if (rightPress == true && downPress == true) {
fishy.x1 += speed;
fishy.y1 += speed;
}
System.out.println("PRESSING (Left:" + leftPress + ") (Right:" + rightPress + ") (Up:" + upPress + ") (Down:" + downPress + ")");
repaint();
}
@Override
public void keyReleased(KeyEvent e) {
if (up == e.getKeyCode()) {
upPress = false;
}
if (down == e.getKeyCode()) {
downPress = false;
}
if (left == e.getKeyCode()) {
leftPress = false;
}
if (right == e.getKeyCode()) {
rightPress = false;
}
}
@Override
public void mouseMoved(MouseEvent e) {
DraggingShapes.showPointerLocation(e.getX(), e.getY());
repaint();
}
/*** METHODS THAT WE'RE NOT GOING TO USE ***/
@Override
public void keyTyped(KeyEvent e) {
}
@Override
public void mouseDragged(MouseEvent e) {
}
}