broadcast

问题 I am developing an app receiving UPD broadcast packet from Wi-Fi camera. It used to be good before I found the problem in receiving UPD broadcast packet at Google Pixel 2 / Pixel 2 XL. To figure out the reason, I made 2 test apps: one is UPD broadcast sender( https://senatech.box.com/s/gmhr391pbl32lqai0mhkffyk6j0ckle5 ), the other is UDP broadcast receiver( https://senatech.box.com/s/abamuor47nlafocs035nfuj90d0uvx0m ). I have tested them on some android devices and found that Google Pixel 2 /

问题 Let's say that I want to send an udp message to every host in my subnet (and then receive an udp message from any host in my subnet): at the moment I do: IPAddress broadcast = IPAddress.Parse("192.168.1.255"); but of course I want this to be done dinamically in the event that the subnet is different from 192.168.1/24. I've tried with: IPAddress broadcast = IPAddress.Broadcast; but IPAddress.Broadcast represents "255.255.255.255" which can't be used to send messages (it throws an exception)..

问题 I am trying to control universal music playback (play/pause, skip etc.) by emulating headset music controls. Is there a way to broadcast the ACTION_MEDIA_BUTTON intent? I tried the regular way with sendBroadcast() but it didn't work. Is this possible? 回答1: Try this long eventtime = SystemClock.uptimeMillis(); Intent downIntent = new Intent(Intent.ACTION_MEDIA_BUTTON, null); KeyEvent downEvent = new KeyEvent(eventtime, eventtime, KeyEvent.ACTION_DOWN, KeyEvent.KEYCODE_MEDIA_PLAY_PAUSE, 0);

问题 I want to broadcast data from one device using Bluetooth to numerous nearby devices. Now, I know Bluetooth broadcasting exists, but is it possible using Android's existing API? If not, are there any other 3rd party APIs available out there which are capable of it? Another question regarding Bluetooth broadcasting: Can you start listening to an ongoing broadcast and receive data from it, even if you weren't listening since the broadcast has started? For example, let device A be the broadcaster

问题 I want to broadcast data from one device using Bluetooth to numerous nearby devices. Now, I know Bluetooth broadcasting exists, but is it possible using Android's existing API? If not, are there any other 3rd party APIs available out there which are capable of it? Another question regarding Bluetooth broadcasting: Can you start listening to an ongoing broadcast and receive data from it, even if you weren't listening since the broadcast has started? For example, let device A be the broadcaster

问题 I am trying to generate a numpy array with elements as two other numpy arrays, as below. W1b1 = np.zeros((256, 161)) W2b2 = np.zeros((256, 257)) Wx = np.array([W1b1, W2b2], dtype=np.object) this gives an error: ValueError: could not broadcast input array from shape (256,161) into shape (256). However, if I take entirely different dimensions for of W1b1 and W2b2 then I do not get an error, as below. A1 = np.zeros((256, 161)) A2 = np.zeros((257, 257)) A3 = np.array([A1, A2], dtype=np.object) I

问题 I am currently trying to make a broadcast receiver which will invoke after android device boots and then will run a background service. I have tried many examples but don't know where I'm going wrong. I am following this example: https://github.com/commonsguy/cw-advandroid/tree/master/SystemEvents/OnBoot I have imported this whole project in my workspace and tried to run. But the receiver didn't invoked or so. Please help me out. My Testing Device is: Motorolla Xoom with ICS 4.0.3 EDIT

问题 I am currently trying to make a broadcast receiver which will invoke after android device boots and then will run a background service. I have tried many examples but don't know where I'm going wrong. I am following this example: https://github.com/commonsguy/cw-advandroid/tree/master/SystemEvents/OnBoot I have imported this whole project in my workspace and tried to run. But the receiver didn't invoked or so. Please help me out. My Testing Device is: Motorolla Xoom with ICS 4.0.3 EDIT

问题 I am trying to create multiple proximity alerts but I cant get it to work... I think that the broadcast receiver gets overwritten and thus is handling only the last broadcast. So if I had two points close by only the one whose intent was created last will generate an alert... I read that I should use request codes but I have no idea on how to do that... My method for setting up the pending intents and the broadcast receiver... private void addProximityAlert(double latitude, double longitude,

问题 I need to disable IPv6. For that the java documentation indicates setting jvm property java.net.preferIPv4Stack=true . But I don't understand how to do it from the code itself. Many forums demonstrated doing it from the command prompt, but I need to do it at runtime. 回答1: You can use System.setProperty("java.net.preferIPv4Stack" , "true"); This is equivalent to passing it in the command line via -Djava.net.preferIPv4Stack=true 回答2: Another approach, if you're desperate and don't have access