I found this example of how to read from a Bluetooth socket using a separate read thread on the Android developer website. The read thread is defined in the private inner class "ConnectedThread".
class MyBluetoothService(
// handler that gets info from Bluetooth service
private val handler: Handler) {
private inner class ConnectedThread(private val mmSocket: BluetoothSocket) : Thread() {
private val mmInStream: InputStream = mmSocket.inputStream
private val mmOutStream: OutputStream = mmSocket.outputStream
private val mmBuffer: ByteArray = ByteArray(1024) // mmBuffer store for the stream
override fun run() {
var numBytes: Int // bytes returned from read()
// Keep listening to the InputStream until an exception occurs.
while (true) {
// Read from the InputStream.
numBytes = try {
mmInStream.read(mmBuffer)
} catch (e: IOException) {
Log.d(TAG, "Input stream was disconnected", e)
break
}
// Send the obtained bytes to the UI activity.
val readMsg = handler.obtainMessage(
MESSAGE_READ, numBytes, -1,
mmBuffer)
readMsg.sendToTarget()
}
}
//Other functions like write, cancel that I omitted from this example
}
So I added a function in MyBluetoothService to start the read thread:
@JvmStatic
fun read(){
val reader = ConnectedThread(myBluetoothSocket)
Reader.start()
}
But this gives an immediate error:
Constructor of inner class ConnectedThread can be called only with receiver of containing class
How should I start the thread from the example code?
Your ConnectedThread is an inner class of MyBluetoothService so it can't be instantiated outside an instance of MyBluetoothService.
Change it like this (remove private inner):
class ConnectedThread(private val mmSocket: BluetoothSocket) : Thread() {
You'll have to get access to the service some other way, or alternatively create a factory method in your service that instantiates the thread and returns that.
But your function is static, so it has no instance of the service.
I tested it, and this is true. Thank you.