[英]Java for-loop problem
問題是我試圖使某些瓷磚被遮擋,以使玩家無法在它們上面行走。 但是,它只讀取了第一個圖塊,它是board[0][0]
,其他所有內容均未選中。
我究竟做錯了什么? :(
這是我的代碼:
import java.applet.*;
import java.applet.Applet;
import java.awt.*;
import java.awt.Canvas.*;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.event.*;
public class gen extends Applet implements KeyListener {
Image[] tiles;
Image player;
int x;
int y;
int px;
int py;
boolean left;
boolean right;
boolean down;
boolean up;
int[][] board;
final int NUM_TILES = 5;
public final int BLOCKED = 1;
public void init() {
// Load board
board = loadBoard();
tiles = new Image[NUM_TILES];
for(int i = 0;i < NUM_TILES;i++) {
tiles[i] = getImage(getClass().getResource(String.format("tile%d.png", i)));
}
for (int y=0;y< NUM_TILES;y++) {
board[1][1] = BLOCKED;
board[1][2] = BLOCKED;
board[1][3] = BLOCKED;
}
player = getImage(getClass().getResource("player.png")); // our player
addKeyListener(this);
px = 0;
py = 0;
}
public void keyPressed(KeyEvent e) {
if (e.getKeyCode() == KeyEvent.VK_LEFT) {
left = true;
px = px - 32;
}
if (e.getKeyCode() == KeyEvent.VK_RIGHT) {
right = true;
px = px + 32;
}
if (e.getKeyCode() == KeyEvent.VK_DOWN) {
down = true;
py = py + 32;
}
if (e.getKeyCode() == KeyEvent.VK_UP) {
up = true;
py = py - 32;
}
repaint();
}
public void keyReleased(KeyEvent e) {
} // ignore
public void keyTyped(KeyEvent e) {
} // ignore
public void paint(Graphics g) {
x = 0;
y = 0;
// here's a sample map!
// but we're loading from a text file!
// so... why is this needed?
for (int row = 0; row < board.length; row++) {
for (int col = 0; col < board[row].length; col++) {
int index = board[row][col];
g.drawImage(tiles[index], 32 * col, 32 * row, this);
if (board[row][col] == BLOCKED) {
System.out.println("\n"+board[row][col] + "is BLOCKED!\n");
}else{System.out.println("\n"+board[row][col] + "is NOT Blocked!\n");}
}
}
g.drawImage(player, px, py, this);
try {
System.out.println("ON BLOCKED TILE?: " + blocked(px,py) + "\n");
}catch(ArrayIndexOutOfBoundsException e) {}
} // end paint method
public void update(Graphics g) {
paint(g);
}
private int[][] loadBoard() {
int[][] board = {
{ 0, 1, 2, 3, 4, 4, 3, 4 },
{ 0, 1, 2, 3, 4, 4, 3, 4 },
{ 2, 2, 4, 2, 2, 1, 1, 0 },
{ 0, 1, 2, 3, 4, 4, 3, 4 },
{ 0, 0, 0, 2, 3, 4, 4, 2 },
{ 2, 2, 4, 2, 2, 1, 1, 0 },
{ 0, 1, 2, 3, 4, 4, 3, 4 },
{ 0, 0, 0, 2, 3, 4, 4, 2 }
};
return board;
}
public boolean blocked(int tx, int ty) {
return board[tx][ty] == BLOCKED;
}
} // end whole thing
您的代碼中的問題之一是在此行上您以32的倍數的px,py調用被阻止:
blocked(px, py)
但是,您將這些數字用作數組的索引,這將導致ArrayIndexOutOfBoundsException
:
public boolean blocked(int tx, int ty)
{
return board[tx][ty] == BLOCKED;
}
您嘗試通過忽略來“修復”它:
try
{
System.out.println("ON BLOCKED TILE?: " + blocked(px,py) + "\n");
}
catch(ArrayIndexOutOfBoundsException e) {}
所以我懷疑它僅適用於(0,0),因為(32,32)超出范圍。 您的代碼中還存在其他錯誤,但這對您來說是一個好的開始。
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