USB 读卡器回车符问题
问题描述：Activity onKeyUp 回调无法无法受到回车符的KeyCode
问题原因：Activity 中 Button 按钮拦截了KEYCODE_ENTRER事件
修改方案：Button 增加 android:focusable=”false” 属性
@UiThread
public class View implements Drawable.Callback, KeyEvent.Callback,
AccessibilityEventSource {
public boolean onKeyDown(int keyCode, KeyEvent event) {
if (KeyEvent.isConfirmKey(keyCode)) {
if ((mViewFlags & ENABLED_MASK) == DISABLED) {
return true;
}
if (event.getRepeatCount() == 0) {
// Long clickable items don't necessarily have to be clickable.
final boolean clickable = (mViewFlags & CLICKABLE) == CLICKABLE
|| (mViewFlags & LONG_CLICKABLE) == LONG_CLICKABLE;
if (clickable || (mViewFlags & TOOLTIP) == TOOLTIP) {
// For the purposes of menu anchoring and drawable hotspots,
// key events are considered to be at the center of the view.
final float x = getWidth() / 2f;
final float y = getHeight() / 2f;
if (clickable) {
setPressed(true, x, y);
}
checkForLongClick(
ViewConfiguration.getLongPressTimeout(),
x,
y,
// This is not a touch gesture -- do not classify it as one.
TOUCH_GESTURE_CLASSIFIED__CLASSIFICATION__UNKNOWN_CLASSIFICATION);
return true;
}
}
}
return false;
}
public boolean onKeyUp(int keyCode, KeyEvent event) {
if (KeyEvent.isConfirmKey(keyCode)) {
if ((mViewFlags & ENABLED_MASK) == DISABLED) {
return true;
}
if ((mViewFlags & CLICKABLE) == CLICKABLE && isPressed()) {
setPressed(false);
if (!mHasPerformedLongPress) {
// This is a tap, so remove the longpress check
removeLongPressCallback();
if (!event.isCanceled()) {
return performClickInternal();
}
}
}
}
return false;
}
}
public class KeyEvent extends InputEvent implements Parcelable {
/** Whether key will, by default, trigger a click on the focused view.
* @hide
*/
@UnsupportedAppUsage
public static final boolean isConfirmKey(int keyCode) {
switch (keyCode) {
case KeyEvent.KEYCODE_DPAD_CENTER:
case KeyEvent.KEYCODE_ENTER:
case KeyEvent.KEYCODE_SPACE:
case KeyEvent.KEYCODE_NUMPAD_ENTER:
return true;
default:
return false;
}
}
}
