我正在用Java编写一个游戏，现在它是Swing + JOGL - 一个带有GLCanvas的JFrame。
我使用keyPressed等事件（jframe.addKeyListener(...)）来处理输入，但它似乎无法正常工作：
我做错了什么？
在Java中有更好的处理键盘输入的方法吗？
（我宁愿切换到另一个库，比如LWJGL ......除非我别无选择）。
答案 0 :(得分：5)
为了减少依赖关系，我会选择“内置”键盘处理。如果你知道你在做什么，它的工作正常。我将从我的游戏中粘贴一些代码：
它使用自定义重复延迟/速率处理密钥重复，并且没有关于组件键盘焦点所在的问题。
public class GameKeyController implements KeyEventDispatcher {
private final int MAX_REPEAT_RATE = 100; // Hz
private final LocalGame game;
private final GamingContext context;
private final Account account;
Timer keyRepeatTimer;
Map<Move, TimerTask> repeatingTasks = new EnumMap<Move, TimerTask>(Move.class);
public GameKeyController(LocalGame game, GamingContext context,
Account account) {
this.game = game;
this.context = context;
this.account = account;
}
public boolean dispatchKeyEvent(KeyEvent e) {
assert EventQueue.isDispatchThread();
int kc = e.getKeyCode();
if (e.getID() == KeyEvent.KEY_PRESSED) {
// If repeat is activated, ignore KEY_PRESSED events.
// Should actually not occur, since KEY_RELEASED *should* have been
// intercepted since last KEY_PRESSED.
if (kc == account.getInt(KC_MOVE_LEFT) && !isRepeating(LEFT)) move(LEFT);
if (kc == account.getInt(KC_MOVE_RIGHT) && !isRepeating(RIGHT)) move(RIGHT);
if (kc == account.getInt(KC_SOFT_DROP) && !isRepeating(SOFT_DROP)) move(SOFT_DROP);
// Regular moves
if (kc == account.getInt(KC_ROT_CW)) move(ROT_CW);
if (kc == account.getInt(KC_ROT_CW2)) move(ROT_CW);
if (kc == account.getInt(KC_ROT_CCW)) move(ROT_CCW);
if (kc == account.getInt(KC_ROT_CCW2)) move(ROT_CCW);
if (kc == account.getInt(KC_HARD_DROP)) move(HARD_DROP);
if (kc == account.getInt(KC_SLIDE_DROP)) move(SLIDE_DROP);
if (kc == account.getInt(KC_FULL_LEFT)) move(FULL_LEFT);
if (kc == account.getInt(KC_FULL_RIGHT)) move(FULL_RIGHT);
if (kc == account.getInt(KC_HOLD)) move(HOLD);
if (kc == account.getInt(KC_SEND_TO_ME)) useSpecial(0);
if (kc == account.getInt(KC_SEND_TO_1)) useSpecial(1);
if (kc == account.getInt(KC_SEND_TO_2)) useSpecial(2);
if (kc == account.getInt(KC_SEND_TO_3)) useSpecial(3);
if (kc == account.getInt(KC_SEND_TO_4)) useSpecial(4);
if (kc == account.getInt(KC_SEND_TO_5)) useSpecial(5);
if (kc == account.getInt(KC_SEND_TO_6)) useSpecial(6);
if (kc == account.getInt(KC_SEND_TO_7)) useSpecial(7);
if (kc == account.getInt(KC_SEND_TO_8)) useSpecial(8);
if (kc == account.getInt(KC_SEND_TO_9)) useSpecial(9);
// Reported bug: Key repeat "lags on releases", that is, the key
// continues to repeat a few ms after it has been released.
// The following two lines gives one "upper" approximation of
// when someone really wants to release the key.
if (kc == account.getInt(KC_MOVE_RIGHT)) stopRepeating(LEFT);
if (kc == account.getInt(KC_MOVE_LEFT)) stopRepeating(RIGHT);
}
if (e.getID() == KeyEvent.KEY_RELEASED) {
if (kc == account.getInt(KC_MOVE_LEFT)) stopRepeating(LEFT);
if (kc == account.getInt(KC_MOVE_RIGHT)) stopRepeating(RIGHT);
if (kc == account.getInt(KC_SOFT_DROP)) stopRepeating(SOFT_DROP);
}
return false;
}
private synchronized void stopRepeating(Move m) {
if (!isRepeating(m))
return;
repeatingTasks.get(m).cancel();
repeatingTasks.remove(m);
}
private synchronized boolean isRepeating(Move m) {
return repeatingTasks.get(m) != null;
}
private synchronized void move(Move move) {
assert EventQueue.isDispatchThread();
context.notIdleSinceStart();
PlayfieldEvent pfe = game.move(move);
// Fake wall kicks
if ((move == ROT_CW || move == ROT_CCW) &&
account.getBool(USE_FAKE_WALL_KICKS) && !pfe.pfChanged) {
// Try RIGHT and ROT, then LEFT and ROT.
Playfield pf = game.getPlayfield();
if (pf.isFakeRotPossible(true, move == ROT_CW)) {
game.move(RIGHT);
game.move(move);
} else if (pf.isFakeRotPossible(false, move == ROT_CW)) {
game.move(LEFT);
game.move(move);
}
}
// Initiate key repeats
int delay = account.getInt(KEY_REPEAT_DELAY);
int rate = account.getInt(KEY_REPEAT_RATE);
if (delay > 0 && rate > 0 && isRepeatable(move))
startRepeating(move);
}
private boolean isRepeatable(Move m) {
return m == LEFT || m == RIGHT || m == SOFT_DROP;
}
private synchronized void startRepeating(Move move) {
assert EventQueue.isDispatchThread();
if (isRepeating(move))
return;
long delay = account.getInt(KEY_REPEAT_DELAY);
int rate = account.getInt(KEY_REPEAT_RATE);
Move repeatMove = move;
if (rate >= MAX_REPEAT_RATE) {
rate = MAX_REPEAT_RATE;
repeatMove = move == LEFT ? FULL_LEFT
: move == RIGHT ? FULL_RIGHT
: move == SOFT_DROP ? SLIDE_DROP
: null; // not a repeatable move!
}
long period = (long) (1000.0 / rate);
if (move == SOFT_DROP)
delay = period;
final Move m = repeatMove;
TimerTask tt = new TimerTask() {
// Should only be executed by keyRepeatTimer thread.
public void run() {
// Remove the if-branch below and you get old school GB behavior
// With the if-branch it's more TDS-ish.
// TODO: Make this depend on an account-setting
if (m == SOFT_DROP && game.getPlayfield().isTetOnSurface()) {
stopRepeating(SOFT_DROP);
return;
}
game.move(m);
// Attempt to make it more responsive to key-releases.
// Even if there are multiple this-tasks piled up (due to
// "scheduleAtFixedRate") we don't want this thread to take
// precedence over AWT thread.
Thread.yield();
}
};
repeatingTasks.put(move, tt);
keyRepeatTimer.scheduleAtFixedRate(tt, delay, period);
}
public synchronized void init() {
if (!isInited()) {
keyRepeatTimer = new Timer("Key Repeat Timer");
KeyboardFocusManager.getCurrentKeyboardFocusManager().addKeyEventDispatcher(this);
}
}
public synchronized boolean isInited() {
return keyRepeatTimer != null;
}
public synchronized void uninit() {
if (isInited()) {
KeyboardFocusManager.getCurrentKeyboardFocusManager().removeKeyEventDispatcher(this);
keyRepeatTimer.cancel();
keyRepeatTimer = null;
}
}
private void useSpecial(int target) {
context.notIdleSinceStart();
context.useSpecial(target);
}
}
答案 1 :(得分：1)
本文中global event listeners的一些提示包括使用KeyboardFocusManager捕获关键事件，并可能有助于从失去焦点中恢复过来。
关于3+键，由于KeyEvent考虑修饰符而不考虑其API中的多个（常规）键，因此这将是棘手的。您可能必须自己管理新闻状态，因为如果您获得KEY_PRESSED，则存储该键并构建当前按下的键集。但是如果按下3个或更多按键时根本没有得到任何事件，我不确定你能做多少。
编辑：此外，JGame库有一个JOGL目标。看看它如何处理关键事件可能会有所帮助。我知道它可以同时处理至少2个键。