我計劃的想法是創建一個圖片,並具有畫面在圖形窗口移動起來,這也正是rollBall()
方法做什麼。當我在run()
方法中使用rollBall()
方法時,該方法起作用。但問題在於,當我將rollBall()
方法放在keyPressed()
方法中時,它無法運行。創建一個移動的物體時,用戶按下一個鍵(JAVA)
我用acm.jar
庫,因爲它是一個用於創建Java圖形程序更加的有用工具。
有人請指點我正確的方向。
這是我的代碼...
import java.awt.Color;
import java.awt.event.KeyEvent;
import acm.graphics.GImage;
import acm.graphics.GOval;
import acm.program.GraphicsProgram;
import acm.util.RandomGenerator;
public class BallDrop extends GraphicsProgram {
/** width and height of application window in pixels */
public static final int APPLICATION_WIDTH = 900;
public static final int APPLICATION_HEIGHT = 768;
private static final double GRAVITY = 1;
/** Radius of the ball in pixels */
private static final int BALL_RADIUS = 50;
private static final int WIDTH = APPLICATION_WIDTH;
public void run() {
setSize(APPLICATION_WIDTH, APPLICATION_HEIGHT);
addKeyListeners();
}
public void keyPressed(KeyEvent e){
char linkMoveRightKey = e.getKeyChar();
if(linkMoveRightKey == 'z'){
rollBall();
}
}
private void rollBall(){
setup_Ball();
game_Loop();
}
private void setup_Ball(){
pic = new GImage("link.png");
add(pic,gameBallInitialLocationX, gameBallInitialLocationY);
}
private void game_Loop(){
while(pic.getX() > 0){
move_Ball();
pause(DELAY);
}
}
private void move_Ball() {
ballVelocityX = 0;
ballVelocityY -= GRAVITY;
pic.move(ballVelocityX, ballVelocityY);
}
private RandomGenerator rgen = RandomGenerator.getInstance();
private GImage pic;
private int gameBallInitialLocationX = 500;
private int gameBallInitialLocationY = 500;
private int ballVelocityX = (int) rgen.nextDouble(3.0, 5.0);
private int ballVelocityY =10;
private static final int DELAY = 50;
}
從未聽說過'acm'庫中的相應方法,但我一直在使用,在所有這些年來從無到有我自己的包。您是否閱讀手冊,是否需要在使用pic.move(ballVelocityX,ballVelocityY);' – Subs
'移動後刷新任何容器,這是不需要的。 – Nicholas