Kotlin：runOnUiThread 未解决的参考

Question

我正在尝试使用 Activity.runOnUiThread(Runnable)，但 Android Studio 似乎认为该函数不存在。我已确保导入“android.app.Activity”。

我正在尝试使用线程连接到蓝牙设备并读取数据。我列出了已配对的设备，单击其中一个已配对的设备会将我带到第二个屏幕，然后我可以在其中连接/断开与所选设备的插座。连接和断开连接正常。

我现在尝试将数据流从 readThread 内部类发送回 UI 线程，但无法让 runOnUiThread 工作。无论我做什么，runOnUiThread 都无法被识别。

package com.example.idxdatalogger

import android.bluetooth.BluetoothAdapter
import android.bluetooth.BluetoothDevice
import android.bluetooth.BluetoothSocket
import android.os.Bundle
import android.os.Handler
import android.os.Looper
import android.os.Message
import android.util.Log
import android.view.View
import android.app.Activity
import androidx.appcompat.app.AppCompatActivity
import kotlinx.android.synthetic.main.activity_second.*
import java.io.IOException
import java.io.InputStream
import java.util.*



class SecondActivity : AppCompatActivity() {
    var btAdapter: BluetoothAdapter? = null

    var data = arrayListOf<String>()

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_second)

        btAdapter = BluetoothAdapter.getDefaultAdapter()

        val position = (intent.getStringExtra("position"))!!.toInt()
        val uuid = UUID.fromString(intent.getStringExtra("UUID"))

        //textView.text = position.toString()
        //textView2.text = uuid.toString()

        val pairedDevices: Set<BluetoothDevice> = btAdapter!!.bondedDevices

        btDeviceLabel.text = pairedDevices.elementAt(position).name.toString()

        var inStream = connectStream(uuid, position, pairedDevices.elementAt(position), btAdapter)

        conStat(inStream)

        connectButton.setOnClickListener {
            inStream.start()
            conStat(inStream)
        }

        cancelButton.setOnClickListener {
            inStream.cancel()
            conStat(inStream)
            inStream = connectStream(uuid, position, pairedDevices.elementAt(position), btAdapter)
        }

    }

    /*
    change text and button visiblity for connect/disconnect buttons
     */
    fun conStat(inStream: connectStream) {
        if (inStream.socket!!.isConnected) {
            socketStatus.text = getString(R.string.connectionOpened)
            connectButton.visibility = View.INVISIBLE
            cancelButton.visibility = View.VISIBLE
        } else {
            socketStatus.text = getString(R.string.connectionClosed)
            connectButton.visibility = View.VISIBLE
            cancelButton.visibility = View.INVISIBLE
        }

    }

    class connectStream(
        private val uuid: UUID,
        private val position: Int,
        private val device: BluetoothDevice,
        private val adapter: BluetoothAdapter?
    ) : Thread() {
        val socket: BluetoothSocket? = device.createRfcommSocketToServiceRecord(uuid)

        override fun run() {

            adapter?.cancelDiscovery()

            try {
                socket?.connect()

                manageConnection().readThread(socket!!).start()
            } catch (e: IOException) {
                Log.i("SOCKET: ", "Failed to connect")
                Log.i("UUID: ", uuid.toString())
                Log.i("Device: ", device.name)
                Log.i("Address: ", device.address)
            }
        }

        fun cancel() {
            try {
                socket?.close()
            } catch (e: IOException) {
                Log.i("SOCKET: ", "Could not close socket")
            }
        }

    }

    class manageConnection() {
        private val MESSAGE_READ: Int = 0
        inner class readThread(socket: BluetoothSocket) : Thread() {
            private val inStream: InputStream = socket.inputStream
            private val inBuffer: ByteArray = ByteArray(1024)

            override fun run() {
                var readBytes: Int

                while (true) {
                    readBytes = try { inStream.read(inBuffer)
                    } catch (e: IOException) {
                        Log.d("IN_STREAM: ", "Input stream disconnected")
                        break
                    }
                    SecondActivity.runOnUiThread(Runnable {

                    })
                }
            }
        }
    }
}

编辑：

重写我的程序以使用 Thread(Runnable{})，而不是为每个线程使用单独的类实例。runOnUiThread 现在可以正常工作。我已在下面发布了更新的代码，但这尚未完全发挥作用。现在，我们可以认为这个问题已经解决了。

package com.example.idxdatalogger

import android.bluetooth.BluetoothAdapter
import android.bluetooth.BluetoothDevice
import android.bluetooth.BluetoothSocket
import android.util.Log
import android.view.View
import android.app.Activity
import android.content.Context
import android.content.Intent
import android.content.res.Configuration
import android.os.*
import android.view.LayoutInflater
import android.view.ViewGroup
import android.widget.BaseAdapter
import android.widget.TextView
import android.widget.Toast
import androidx.appcompat.app.AppCompatActivity
import kotlinx.android.synthetic.main.activity_second.*
import java.io.IOException
import java.io.InputStream
import java.util.*

/*

 */
class SecondActivity : AppCompatActivity() {
    var btAdapter: BluetoothAdapter? = null
    var data = arrayListOf<String>()

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_second)

        btAdapter = BluetoothAdapter.getDefaultAdapter()

        val position = (intent.getStringExtra("position"))!!.toInt()
        val uuid = UUID.fromString(intent.getStringExtra("UUID"))

        val pairedDevices: Set<BluetoothDevice> = btAdapter!!.bondedDevices
        val device = pairedDevices.elementAt(position)

        btDeviceLabel.text = pairedDevices.elementAt(position).name.toString()

        val socket: BluetoothSocket? = device.createRfcommSocketToServiceRecord(uuid)

        //var inStream = connectStream(uuid, position, pairedDevices.elementAt(position), btAdapter)
        conStat(socket!!)


        val inStream: InputStream = socket.inputStream
        val inBuffer: ByteArray = ByteArray(1024)

        var readBytes : Int

        connectButton.setOnClickListener {
            //connect to device
            Thread(Runnable {
                kotlin.run {
                    btAdapter?.cancelDiscovery()
                    try {
                        socket.connect()
                        runOnUiThread(Runnable { conStat(socket) })
                        //read stream
                        Thread(Runnable{
                            while(true) {
                                readBytes = try {
                                    inStream.read(inBuffer)
                                } catch (e: IOException) {
                                    Log.d("IN_STREAM: ", "input stream disconnected")
                                    break
                                }
                                //return stream information to UI thread
                                runOnUiThread(Runnable {
                                    data.add(inBuffer.toString())
                                    dataList.adapter = dataListAdapter(this,data)
                                    dataList.visibility = View.VISIBLE
                                })
                            }
                        }).start()
                    } catch (e: IOException) {
                        Log.i("SOCKET: ", "Failed to connect")
                        Log.i("UUID: ", uuid.toString())
                        Log.i("Device: ", pairedDevices.elementAt(position).name)
                        Log.i("Address: ", pairedDevices.elementAt(position).address)
                    }
                }
            }).start()

        }

        cancelButton.setOnClickListener {
            //close socket connection
            Thread(Runnable {
                try {
                    socket.close()
                } catch (e: IOException) {
                    Log.i("SOCKET: ", "Could not close socket")
                }
                runOnUiThread(Runnable {
                    conStat(socket)
                    val intent = Intent(this, MainActivity::class.java)
                    startActivity(intent)
                })
            }).start()
        }
    }

    /*
    change text and button visiblity for connect/disconnect buttons
     */
    fun conStat(socket : BluetoothSocket) {
        if (socket.isConnected) {
            socketStatus.text = getString(R.string.connectionOpened)
            connectButton.visibility = View.INVISIBLE
            cancelButton.visibility = View.VISIBLE
        } else {
            socketStatus.text = getString(R.string.connectionClosed)
            connectButton.visibility = View.VISIBLE
            cancelButton.visibility = View.INVISIBLE
        }
    }

Answer 1

SecondActivity.runOnUiThread(...)是不正确的，因为您正在调用类上的方法并且runOnUiThread()方法不是静态的。您需要在类的实例上调用此方法Activity，而不是在类本身上。

Answer 2

你必须添加inner到你的manageConnection班级然后你就可以使用runOnUiThread {}