我正在尝试初始化突破游戏，以便游戏从在指定位置添加到画布的桨开始，然后用鼠标移动相同的桨。
所以，1. 创建桨并添加到画布上 2. 移动桨，因为它跟踪鼠标的位置。
问题：添加到画布的桨保持原位，但另一个未添加到画布的桨根据事件侦听器移动。一个桨保持静止，另一个跟踪鼠标。我已将 add(paddle) 语句移至鼠标
ENV：Mac OSX 10.8.4，JVM 1.6（随 OSX 一起安装）
java中是否有某种设置需要设置为在鼠标事件时刷新桨？还是环境问题？
/*
* File: Breakout.java
* -------------------
* Name:
* Section Leader:
*
* This file will eventually implement the game of Breakout.
*/
import acm.graphics.*;
import acm.program.*;
import acm.util.*;
import java.applet.*;
import java.awt.*;
import java.awt.event.*;
public class Breakout extends GraphicsProgram {
/** Width and height of application window in pixels */
public static final int APPLICATION_WIDTH = 400;
public static final int APPLICATION_HEIGHT = 600;
/** Dimensions of game board
* Should not be used directly (use getWidth()/getHeight() instead).
* * */
private static final int WIDTH = APPLICATION_WIDTH;
private static final int HEIGHT = APPLICATION_HEIGHT;
/** Dimensions of the paddle */
private static final int PADDLE_WIDTH = 60;
private static final int PADDLE_HEIGHT = 10;
/** Offset of the paddle up from the bottom */
private static final int PADDLE_Y_OFFSET = 30;
/** Number of bricks per row */
private static final int NBRICKS_PER_ROW = 10;
/** Number of rows of bricks */
private static final int NBRICK_ROWS = 10;
/** Separation between bricks */
private static final int BRICK_SEP = 4;
/** Width of a brick */
private static final int BRICK_WIDTH =
(WIDTH - (NBRICKS_PER_ROW - 1) * BRICK_SEP) / NBRICKS_PER_ROW;
/** Height of a brick */
private static final int BRICK_HEIGHT = 8;
/** Radius of the ball in pixels */
private static final int BALL_RADIUS = 10;
/** Offset of the top brick row from the top */
private static final int BRICK_Y_OFFSET = 70;
/** Number of turns */
private static final int NTURNS = 3;
/** ADDED KNM Private Instance Variables */
private GRect paddle;
/* Method: run() */
/** Runs the Breakout program. */
public void run() {
/* You fill this in, along with any subsidiary methods */
init();
}
public void init(){
addMouseListeners();
setSize(APPLICATION_WIDTH,APPLICATION_HEIGHT);
prepTiles();
prepPaddle();
}
private void prepTiles(){
for (int i = 1; i <= NBRICK_ROWS; i++){
int x_pos_start = 0;//(CANVAS_MIDDLE - BRICK_WIDTH/2) - (NBRICKS_PER_ROW/2 - 2)*BRICK_WIDTH;
int y_pos = BRICK_Y_OFFSET + (i-1)*(BRICK_HEIGHT+BRICK_SEP);
Color BRICK_COLOR = getBRICK_COLOR(i);
//case for color fills
for(int y = 1; y <= NBRICKS_PER_ROW; y++ ){
//adjust to beginning of row then add bricks
int x_pos = x_pos_start + ((y-1)*(BRICK_WIDTH+BRICK_SEP));
G3DRect grect = new G3DRect(x_pos, y_pos, BRICK_WIDTH, BRICK_HEIGHT);
grect.setFilled(true);
grect.setColor(BRICK_COLOR);
add(grect);
}
}
}
public void prepPaddle(){
double x_pos = APPLICATION_WIDTH/2 - PADDLE_WIDTH/2;
double y_pos = APPLICATION_HEIGHT - PADDLE_HEIGHT - PADDLE_Y_OFFSET;
paddle = new GRect(x_pos, y_pos, PADDLE_WIDTH, PADDLE_HEIGHT);
paddle.setFilled(true);
paddle.setColor(Color.DARK_GRAY);
add(paddle); // want to keep this.
}
public void mouseMoved(MouseEvent e){
// add(paddle); // I tried moveing the statement here but, that doesn't create the paddle until the mouse hovers above the application canvas.
paddle.setLocation(e.getX() - PADDLE_WIDTH/2, paddle.getY());
if (paddle.getX() <= 0) paddle.setLocation(0, paddle.getY());
if (paddle.getX() + PADDLE_WIDTH >= getWidth()) paddle.setLocation(getWidth() - PADDLE_WIDTH, paddle.getY());
}
private Color getBRICK_COLOR(int i_row){
switch (i_row){
case 1 :
case 2 : return Color.RED;
case 3 :
case 4 : return Color.ORANGE;
case 5 :
case 6 : return Color.yellow;
case 7 :
case 8 : return Color.green;
case 9 :
case 10: return Color.cyan;
default: return Color.black;
}
}
}