Kotlin: runOnUiThread未解决的引用
Kotlin: runOnUiThread未解决的引用
提问于 2019-08-02 16:45:22
我试图使用Activity.runOnUiThread(Runnable)，但是Android似乎认为这个功能不存在。我已经确定"android.app.Activity“是导入的。
我试图使用线程连接到蓝牙设备并读取数据。我列出了配对设备，并单击其中一个配对设备将我带到第二个屏幕上，在那里我可以连接/断开从所选设备上的套接字。连接和断开正在工作。
我现在正试图从readThread内部类将数据流发送回UI线程，但我无法让runOnUiThread工作。无论我做什么，runOnUiThread都不被认可。
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线程(Runnable{})，而不是为每个线程拥有单独的类实例。runOnUiThread现在正在无问题地工作。我已经在下面发布了我的更新代码，但这还没有完全发挥作用。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
}
}回答 4
Stack Overflow用户
回答已采纳
发布于 2019-08-02 16:54:50
必须将inner添加到manageConnection类中，然后只需使用runOnUiThread {}
Stack Overflow用户
发布于 2019-08-02 16:59:30
SecondActivity.runOnUiThread(...)是不正确的，因为您在类上调用方法，而runOnUiThread()方法不是静态的。您需要在Activity类的实例上调用此方法，而不是在类本身上调用。
Stack Overflow用户
发布于 2019-08-02 18:39:19
请在这里查看runOnUiThread签名：
/**
* Runs the specified action on the UI thread. If the current thread is the UI
* thread, then the action is executed immediately. If the current thread is
* not the UI thread, the action is posted to the event queue of the UI thread.
*
* @param action the action to run on the UI thread
*/
public final void runOnUiThread(Runnable action) {
if (Thread.currentThread() != mUiThread) {
mHandler.post(action);
} else {
action.run();
}
}很明显，它不是静态方法，因此不能将此方法作为静态方法调用如下：
SomeActivity.runOnUiThread {}解决方法可以是将SecondActivity作为一个实例传递，然后轻松地对活动实例执行您想做的任何事情。
class myClass(val activity : Activity){
fun someMethod(){
activity.runOnUithread{}
}
}页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/57330607
复制相关文章
相似问题
腾讯云开发者
