private static final Class<?>[] mSetForegroundSignature = new Class[] {
boolean.class};
private static final Class<?>[] mStartForegroundSignature = new Class[] {
int.class, Notification.class};
private static final Class<?>[] mStopForegroundSignature = new Class[] {
boolean.class};
private NotificationManager mNM;
private Method mSetForeground;
private Method mStartForeground;
private Method mStopForeground;
private Object[] mSetForegroundArgs = new Object[1];
private Object[] mStartForegroundArgs = new Object[2];
private Object[] mStopForegroundArgs = new Object[1];
void invokeMethod(Method method, Object[] args) {
try {
method.invoke(this, args);
} catch (InvocationTargetException e) {
// Should not happen.
Log.w("ApiDemos", "Unable to invoke method", e);
} catch (IllegalAccessException e) {
// Should not happen.
Log.w("ApiDemos", "Unable to invoke method", e);
}
}
/**
* This is a wrapper around the new startForeground method, using the older
* APIs if it is not available.
*/
void startForegroundCompat(int id, Notification notification) {
// If we have the new startForeground API, then use it.
if (mStartForeground != null) {
mStartForegroundArgs[0] = Integer.valueOf(id);
mStartForegroundArgs[1] = notification;
invokeMethod(mStartForeground, mStartForegroundArgs);
return;
}
// Fall back on the old API.
mSetForegroundArgs[0] = Boolean.TRUE;
invokeMethod(mSetForeground, mSetForegroundArgs);
mNM.notify(id, notification);
}
/**
* This is a wrapper around the new stopForeground method, using the older
* APIs if it is not available.
*/
void stopForegroundCompat(int id) {
// If we have the new stopForeground API, then use it.
if (mStopForeground != null) {
mStopForegroundArgs[0] = Boolean.TRUE;
invokeMethod(mStopForeground, mStopForegroundArgs);
return;
}
// Fall back on the old API. Note to cancel BEFORE changing the
// foreground state, since we could be killed at that point.
mNM.cancel(id);
mSetForegroundArgs[0] = Boolean.FALSE;
invokeMethod(mSetForeground, mSetForegroundArgs);
}
@Override
public void onCreate() {
mNM = (NotificationManager)getSystemService(NOTIFICATION_SERVICE);
try {
mStartForeground = getClass().getMethod("startForeground",
mStartForegroundSignature);
mStopForeground = getClass().getMethod("stopForeground",
mStopForegroundSignature);
return;
} catch (NoSuchMethodException e) {
// Running on an older platform.
mStartForeground = mStopForeground = null;
}
try {
mSetForeground = getClass().getMethod("setForeground",
mSetForegroundSignature);
} catch (NoSuchMethodException e) {
throw new IllegalStateException(
"OS doesn't have Service.startForeground OR Service.setForeground!");
}
}
@Override
public void onDestroy() {
// Make sure our notification is gone.
stopForegroundCompat(R.string.foreground_service_started);
}
摘自:http://developer.android.com/reference/android/app/Service.html#startForeground(int, android.app.Notification)