因此，当我尝试通过 TCP 与我的两台平板电脑和支持 Wifi 的外部设备进行通信时，我遇到了一个奇怪的问题。
我会尽力描述问题。该系统的工作原理如下(所有通信均通过无线网络进行):
- 设备 向平板电脑 A 发送 TCP 通信
- tablet A(master)显示消息并将消息重复给 tablet B(slave)-这很好用
- 平板电脑 A 向 平板电脑 B 发送另一条消息(操作 消息)，平板电脑 B 接收该消息没有问题
- 当平板电脑 B 执行操作时，它会向平板电脑 A 发送一条操作消息 - 这就是问题所在，消息确实不会即使发送了也不会被消费。如果我转到另一个
activity并返回到上一个，则消息被消耗
运行 Android 6.0.1 的 Lenovo YT3 平板电脑会出现这种情况
SocketListenerService
private var thread: Thread? = null
private var socketListener: SocketListener? = null
private var broadcastManager: LocalBroadcastManager? = null
val listener = object : SimpleServer.ServerReceivedListener {
override fun onLineReceived(line: String) {
val response = Intent(SOCKET_RESPONSE)
response.putExtra(RESPONSE_MESSAGE, line)
broadcastManager!!.sendBroadcast(response)
}
}
private val incomingServer = SimpleServer(listener)
override fun onCreate() {
super.onCreate()
broadcastManager = LocalBroadcastManager.getInstance(this)
}
override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {
if (intent != null) {
socketListener = SocketListener()
thread = Thread(socketListener)
thread!!.start()
}
return super.onStartCommand(intent, flags, startId)
}
override fun onDestroy() {
super.onDestroy()
socketListener!!.shutDown()
thread!!.interrupt()
incomingServer.closeServer()
}
override fun onBind(intent: Intent): IBinder? {
return null
}
private inner class SocketListener : Runnable {
@Volatile private var done = false
internal fun shutDown() {
done = true
}
override fun run() {
while (!done) {
incomingServer.serve()
}
}
}
companion object {
val SOCKET_RESPONSE = "socket_response"
val RESPONSE_MESSAGE = "response_message"
val port = 9888
}
简单服务器
interface ServerReceivedListener {
fun onLineReceived(line: String)
}
private var server: ServerSocket? = null
private var client: Socket? = null
private var listener: ServerReceivedListener? = null
init {
try {
server = ServerSocket(SocketListenerService.port)
this.listener = listener
} catch (err: Exception) {
err.printStackTrace()
}
}
fun serve() {
var line: String?
try {
if (!server!!.isClosed) {
client = server?.accept()
val r = BufferedReader(InputStreamReader(client!!.getInputStream(), "UTF-8"))
line = r.readLine()
while (line != null) {
if (line.length >= 4)
listener!!.onLineReceived(line)
else
listener!!.onLineReceived("@")
line = r.readLine()
}
}
} catch (e: IOException) {
if (!e.message!!.contains("Socket closed"))
e.printStackTrace()
}
}
fun closeServer() {
try {
if (client != null)
client!!.close()
server!!.close()
} catch (e: IOException) {
e.printStackTrace()
}
}
BroadcastBeceiver 依次从 Intent 获取消息并使用接口(interface)将其发送到 activity
我似乎无法理解为什么当消费 activity 重新启动时，slave 的通信只被 master 消费(?)
最佳答案
这是一个套接字问题。现在我有两个线程在两个端口上监听并且通信正常
关于android - 设备间的双向通信，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/45193160/