下面列出了android.view.KeyEvent#ACTION_DOWN 实例代码，或者点击链接到github查看源代码，也可以在右侧发表评论。
@Override
public boolean dispatchKeyEvent(@NonNull KeyEvent event) {
if (event.getKeyCode() == KeyEvent.KEYCODE_BACK) {
if (event.getAction() == KeyEvent.ACTION_UP) {
if (mIsMultiChoiceModeEnabled) {
setMultiChoiceModeEnabled(false);
setupOkButtonVisibility();
} else {
if (isTopDirectory(mCurrentDirectory)) {
finish();
} else {
readUpDirectory();
}
}
} else if (event.getAction() == KeyEvent.ACTION_DOWN && (event.getFlags() & KeyEvent.FLAG_LONG_PRESS) == KeyEvent.FLAG_LONG_PRESS) {
finish();
}
return true;
}
return super.dispatchKeyEvent(event);
}
/**
* You can call this function yourself to have the scroll view perform
* scrolling from a key event, just as if the event had been dispatched to
* it by the view hierarchy.
*
* @param event The key event to execute.
* @return Return true if the event was handled, else false.
*/
public boolean executeKeyEvent(KeyEvent event) {
boolean handled = false;
if (event.getAction() == KeyEvent.ACTION_DOWN) {
switch (event.getKeyCode()) {
case KeyEvent.KEYCODE_DPAD_LEFT:
handled = arrowScroll(FOCUS_LEFT);
break;
case KeyEvent.KEYCODE_DPAD_RIGHT:
handled = arrowScroll(FOCUS_RIGHT);
break;
case KeyEvent.KEYCODE_TAB:
if (Build.VERSION.SDK_INT >= 11) {
// The focus finder had a bug handling FOCUS_FORWARD and FOCUS_BACKWARD
// before Android 3.0. Ignore the tab key on those devices.
if (KeyEventCompat.hasNoModifiers(event)) {
handled = arrowScroll(FOCUS_FORWARD);
} else if (KeyEventCompat.hasModifiers(event, KeyEvent.META_SHIFT_ON)) {
handled = arrowScroll(FOCUS_BACKWARD);
}
}
break;
}
}
return handled;
}
/**
* You can call this function yourself to have the scroll view perform
* scrolling from a key event, just as if the event had been dispatched to
* it by the view hierarchy.
*
* @param event The key event to execute.
* @return Return true if the event was handled, else false.
*/
public boolean executeKeyEvent(KeyEvent event) {
boolean handled = false;
if (event.getAction() == KeyEvent.ACTION_DOWN) {
switch (event.getKeyCode()) {
case KeyEvent.KEYCODE_DPAD_LEFT:
handled = arrowScroll(FOCUS_LEFT);
break;
case KeyEvent.KEYCODE_DPAD_RIGHT:
handled = arrowScroll(FOCUS_RIGHT);
break;
case KeyEvent.KEYCODE_TAB:
if (Build.VERSION.SDK_INT >= 11) {
// The focus finder had a bug handling FOCUS_FORWARD and FOCUS_BACKWARD
// before Android 3.0. Ignore the tab key on those devices.
if (KeyEventCompat.hasNoModifiers(event)) {
handled = arrowScroll(FOCUS_FORWARD);
} else if (KeyEventCompat.hasModifiers(event, KeyEvent.META_SHIFT_ON)) {
handled = arrowScroll(FOCUS_BACKWARD);
}
}
break;
}
}
return handled;
}
/**
* You can call this function yourself to have the scroll view perform
* scrolling from a key event, just as if the event had been dispatched to
* it by the view hierarchy.
*
* @param event The key event to execute.
* @return Return true if the event was handled, else false.
*/
public boolean executeKeyEvent(KeyEvent event) {
boolean handled = false;
if (event.getAction() == KeyEvent.ACTION_DOWN) {
switch (event.getKeyCode()) {
case KeyEvent.KEYCODE_DPAD_LEFT:
handled = arrowScroll(FOCUS_LEFT);
break;
case KeyEvent.KEYCODE_DPAD_RIGHT:
handled = arrowScroll(FOCUS_RIGHT);
break;
case KeyEvent.KEYCODE_TAB:
if (Build.VERSION.SDK_INT >= 11) {
// The focus finder had a bug handling FOCUS_FORWARD and FOCUS_BACKWARD
// before Android 3.0. Ignore the tab key on those devices.
if (KeyEvent.metaStateHasNoModifiers(event.getMetaState())) {
handled = arrowScroll(FOCUS_FORWARD);
} else if (KeyEvent.metaStateHasNoModifiers(event.getMetaState())) {
handled = arrowScroll(FOCUS_BACKWARD);
}
}
break;
}
}
return handled;
}
public static View.OnKeyListener getSoftInPutHideListener(final Context context) {
View.OnKeyListener onKeyList = new View.OnKeyListener() {
@Override
public boolean onKey(View v, int keyCode, KeyEvent event) {
if ((event.getAction() == KeyEvent.ACTION_DOWN) && (keyCode == KeyEvent.KEYCODE_ENTER)) {
EditTextUtil.hideSoftInPut((EditText) v, context);
return true;
}
return false;
}
};
return onKeyList;
}
/**
* 监听后退退出
*
* @param keyCode 按键码
* @param event 时间
* @return 是否处理完成
*/
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_BACK && event.getAction() == KeyEvent.ACTION_DOWN) {
if ((System.currentTimeMillis() - time > 1000)) {
Toast.makeText(this, getResources().getString(R.string.main_finish_tip),
Toast.LENGTH_SHORT).show();
time = System.currentTimeMillis();
} else {
moveTaskToBack(false);
}
return true;
}
else {
return super.onKeyDown(keyCode, event);
}
}
/**
* You can call this function yourself to have the scroll view perform
* scrolling from a key event, just as if the event had been dispatched to
* it by the view hierarchy.
*
* @param event The key event to execute.
* @return Return true if the event was handled, else false.
*/
public boolean executeKeyEvent(KeyEvent event) {
boolean handled = false;
if (event.getAction() == KeyEvent.ACTION_DOWN) {
switch (event.getKeyCode()) {
case KeyEvent.KEYCODE_DPAD_LEFT:
handled = arrowScroll(FOCUS_LEFT);
break;
case KeyEvent.KEYCODE_DPAD_RIGHT:
handled = arrowScroll(FOCUS_RIGHT);
break;
case KeyEvent.KEYCODE_TAB:
if (Build.VERSION.SDK_INT >= 11) {
// The focus finder had a bug handling FOCUS_FORWARD and FOCUS_BACKWARD
// before Android 3.0. Ignore the tab key on those devices.
if (event.hasNoModifiers()) {
handled = arrowScroll(FOCUS_FORWARD);
} else if (event.hasModifiers(KeyEvent.META_SHIFT_ON)) {
handled = arrowScroll(FOCUS_BACKWARD);
}
}
break;
}
}
return handled;
}
boolean translateAndSendNativeEvents(KeyEvent event) {
if (mNativeImeAdapterAndroid == 0) return false;
int action = event.getAction();
if (action != KeyEvent.ACTION_DOWN &&
action != KeyEvent.ACTION_UP) {
// action == KeyEvent.ACTION_MULTIPLE
// TODO(bulach): confirm the actual behavior. Apparently:
// If event.getKeyCode() == KEYCODE_UNKNOWN, we can send a
// composition key down (229) followed by a commit text with the
// string from event.getUnicodeChars().
// Otherwise, we'd need to send an event with a
// WebInputEvent::IsAutoRepeat modifier. We also need to verify when
// we receive ACTION_MULTIPLE: we may receive it after an ACTION_DOWN,
// and if that's the case, we'll need to review when to send the Char
// event.
return false;
}
mViewEmbedder.onImeEvent(false);
return nativeSendKeyEvent(mNativeImeAdapterAndroid, event, event.getAction(),
getModifiers(event.getMetaState()), event.getEventTime(), event.getKeyCode(),
event.isSystem(), event.getUnicodeChar());
}
private boolean isDpadEvent(KeyEvent event) {
if (event.getAction() == KeyEvent.ACTION_DOWN) {
switch (event.getKeyCode()) {
case KeyEvent.KEYCODE_DPAD_CENTER:
case KeyEvent.KEYCODE_DPAD_DOWN:
case KeyEvent.KEYCODE_DPAD_UP:
case KeyEvent.KEYCODE_DPAD_LEFT:
case KeyEvent.KEYCODE_DPAD_RIGHT:
return true;
}
}
return false;
}
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_BACK
&& event.getAction() == KeyEvent.ACTION_DOWN) {
if ((System.currentTimeMillis() - exitTime) > 2000) {
ShowToast.Short("再按一次退出程序");
exitTime = System.currentTimeMillis();
} else {
finish();
}
return true;
}
return super.onKeyDown(keyCode, event);
}
@Override
public boolean dispatchKeyEvent(KeyEvent event) {
if (player == null || event.getAction() != KeyEvent.ACTION_DOWN) {
return super.dispatchKeyEvent(event);
}
switch (event.getKeyCode()) {
case KeyEvent.KEYCODE_MEDIA_FAST_FORWARD:
case KeyEvent.KEYCODE_DPAD_RIGHT:
fastForward();
break;
case KeyEvent.KEYCODE_MEDIA_REWIND:
case KeyEvent.KEYCODE_DPAD_LEFT:
rewind();
break;
case KeyEvent.KEYCODE_MEDIA_PLAY_PAUSE:
player.setPlayWhenReady(!player.getPlayWhenReady());
break;
case KeyEvent.KEYCODE_MEDIA_PLAY:
player.setPlayWhenReady(true);
break;
case KeyEvent.KEYCODE_MEDIA_PAUSE:
player.setPlayWhenReady(false);
break;
case KeyEvent.KEYCODE_MEDIA_NEXT:
next();
break;
case KeyEvent.KEYCODE_MEDIA_PREVIOUS:
previous();
break;
default:
return false;
}
show();
return true;
}
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if(keyCode == KeyEvent.KEYCODE_BACK && event.getAction() == KeyEvent.ACTION_DOWN){
if((System.currentTimeMillis()-exitTime) > 2000){
Toast.makeText(getApplicationContext(), "再按一次退出程序", Toast.LENGTH_SHORT).show();
exitTime = System.currentTimeMillis();
}
else{
MobclickAgent.onKillProcess(this);
System.exit(0);
}
return true;
}
return super.onKeyDown(keyCode, event);
}
@Override
public boolean sendKeyEvent(KeyEvent event) {
if (this.textbox.getText().length() == 0 && event.getAction() == KeyEvent.ACTION_DOWN && event.getKeyCode() == KeyEvent.KEYCODE_DEL) {
if (TextInputProxyEditTextbox.this._mcpeKeyWatcher != null) {
TextInputProxyEditTextbox.this._mcpeKeyWatcher.onDeleteKeyPressed();
}
return false;
}
return super.sendKeyEvent(event);
}
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if (event.getAction() == KeyEvent.ACTION_DOWN) {
if (keyCode == KeyEvent.KEYCODE_BACK) {
if (webView.canGoBack()) {
webView.goBack();
} else {
finish();
}
return true;
}
}
return super.onKeyDown(keyCode, event);
}
@Override
public boolean onKeyEvent(KeyEvent event, EventId eventId) {
if (event.getAction() == KeyEvent.ACTION_DOWN) {
// Mainly to prevent hints from being activated when typing, attempting to perform
// shortcuts, etc. Doesn't cancel in-progress hint, user can use normal actions to
// cancel (e.g. Ctrl).
cancelA11yHint();
}
return false;
}
@Override
public boolean sendKeyEvent(KeyEvent event) {
if (event.getAction() == KeyEvent.ACTION_DOWN
&& event.getKeyCode() == KeyEvent.KEYCODE_DEL) {
// Un-comment if you wish to cancel the backspace:
// return false;
}
return super.sendKeyEvent(event);
}
@Override
public boolean onKey(View v, int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_BACK && event.getAction() == KeyEvent.ACTION_DOWN &&
isExpanded()) {
boolean keyboardHidden = Utils.hideInputMethod(v);
if (keyboardHidden) return true;
collapse();
return true;
}
return false;
}
public boolean onKeyDown(int keyCode, KeyEvent event) {
if (event.getAction() == KeyEvent.ACTION_DOWN) {
switch (keyCode) {
case KeyEvent.KEYCODE_BACK:
if (webview.canGoBack()) {
webview.goBack();
}
return true;
}
}
//return super.onKeyDown(keyCode, event);
return false;
}
@Override
public boolean onKey(View v, final int keyCode, KeyEvent event) {
LOGI("VolumePanel", "onKey(" + keyCode + ")");
// Don't handle ANYTHING when a call is in progress!
if (mCallState != TelephonyManager.CALL_STATE_IDLE)
return super.onKey(v, keyCode, event);
switch (keyCode) {
// Handle the DOWN + MULTIPLE action (holding down).
case KeyEvent.KEYCODE_VOLUME_UP:
case KeyEvent.KEYCODE_VOLUME_DOWN:
final int adjust = ((keyCode == KeyEvent.KEYCODE_VOLUME_UP) ?
AudioManager.ADJUST_RAISE : AudioManager.ADJUST_LOWER);
switch (event.getAction()) {
case KeyEvent.ACTION_DOWN:
// If another key was pressed while holding on to
// one volume key, we'll need to abort mission.
if (mKeyCodeDown != 0) {
mIgnoreNextKeyUp = true;
mHandler.removeMessages(MSG_VOLUME_LONG_PRESS);
return super.onKey(v, keyCode, event);
}
mKeyCodeDown = event.getKeyCode();
mKeyTimeDown = System.currentTimeMillis();
event.startTracking();
// NOTE: we'll allow long press events if we've set an action.
boolean callIdle = (mCallState == TelephonyManager.CALL_STATE_IDLE);
if (!noLongPress || hasLongPressAction(keyCode)) {
mHandler.sendMessageDelayed(mHandler.obtainMessage(
MSG_VOLUME_LONG_PRESS, event), ((callIdle && hasLongPressAction(keyCode)) ?
mLongPressTimeout : mLongPressTimeout / 2));
}
break;
case KeyEvent.ACTION_UP:
case KeyEvent.ACTION_MULTIPLE:
boolean hasLongPress = mHandler.hasMessages(MSG_VOLUME_LONG_PRESS);
mHandler.removeMessages(MSG_VOLUME_LONG_PRESS);
boolean ignoreNextKeyUp = mIgnoreNextKeyUp;
mIgnoreNextKeyUp = false;
mKeyCodeDown = 0;
// We've been told to let this one go.
if (ignoreNextKeyUp || event.isCanceled()) {
mKeyTimeDown = 0;
return true;
}
if ((hasLongPress || noLongPress) && (System.currentTimeMillis() -
mKeyTimeDown) < mLongPressTimeout) {
mVolumeDirty = true;
mKeyTimeDown = 0;
if (!firstReveal || (firstReveal && isShowing())) {
adjustVolume(adjust);
show();
} else {
reveal();
}
}
break;
}
break;
case KeyEvent.KEYCODE_VOLUME_MUTE:
switch (event.getAction()) {
case KeyEvent.ACTION_UP:
boolean mute = isMuted(STREAM_RING);
mAudioManager.setStreamMute(STREAM_RING, !mute);
mAudioManager.setStreamMute(STREAM_NOTIFICATION, !mute);
mVolumeDirty = true;
show();
break;
}
break;
}
return super.onKey(v, keyCode, event);
}
@Override
public boolean onKey (View view, int keyCode, KeyEvent keyEvent) {
if (ignoreNoGamepadButtons && !keyEvent.isGamepadButton(keyCode)) {
return false;
}
AndroidController controller = controllerMap.get(keyEvent.getDeviceId());
if(controller != null) {
if(controller.getButton(keyCode) && keyEvent.getAction() == KeyEvent.ACTION_DOWN) {
return true;
}
synchronized(eventQueue) {
AndroidControllerEvent event = eventPool.obtain();
event.controller = controller;
if(keyEvent.getAction() == KeyEvent.ACTION_DOWN) {
if (keyCode == KeyEvent.KEYCODE_DPAD_UP) {
event.type = AndroidControllerEvent.POV;
controller.pov |= 0x00000001;
event.povDirection = controller.getPov(0);
} else if (keyCode == KeyEvent.KEYCODE_DPAD_DOWN) {
event.type = AndroidControllerEvent.POV;
controller.pov |= 0x00000010;
event.povDirection = controller.getPov(0);
} else if (keyCode == KeyEvent.KEYCODE_DPAD_RIGHT) {
event.type = AndroidControllerEvent.POV;
controller.pov |= 0x00000100;
event.povDirection = controller.getPov(0);
} else if (keyCode == KeyEvent.KEYCODE_DPAD_LEFT) {
event.type = AndroidControllerEvent.POV;
controller.pov |= 0x00001000;
event.povDirection = controller.getPov(0);
} else {
event.type = AndroidControllerEvent.BUTTON_DOWN;
event.code = keyCode;
}
} else {
if (keyCode == KeyEvent.KEYCODE_DPAD_UP) {
event.type = AndroidControllerEvent.POV;
controller.pov &= 0x00001110;
event.povDirection = controller.getPov(0);
} else if (keyCode == KeyEvent.KEYCODE_DPAD_DOWN) {
event.type = AndroidControllerEvent.POV;
controller.pov &= 0x00001101;
event.povDirection = controller.getPov(0);
} else if (keyCode == KeyEvent.KEYCODE_DPAD_RIGHT) {
event.type = AndroidControllerEvent.POV;
controller.pov &= 0x00001011;
event.povDirection = controller.getPov(0);
} else if (keyCode == KeyEvent.KEYCODE_DPAD_LEFT) {
event.type = AndroidControllerEvent.POV;
controller.pov &= 0x00000111;
event.povDirection = controller.getPov(0);
} else {
event.type = AndroidControllerEvent.BUTTON_UP;
event.code = keyCode;
}
}
eventQueue.add(event);
}
if (keyCode == KeyEvent.KEYCODE_BACK && !Gdx.input.isCatchBackKey()) {
return false;
}
return true;
} else {
return false;
}
}