Kotlin：停止内联线程

Question

我已经创建了一些内联线程，但我现在不确定如何停止它们。我有一个线程打开蓝牙套接字连接，一个关闭，一个读取使用自定义列表视图适配器显示数据的数据。我现在想通过单击按钮停止在屏幕上发布数据。但是，我不确定如何停止这些线程。我是否必须将线程移动到单独的可调用 class 继承自线程基 class 的对象？

connectButton.setOnClickListener {
            //new thread needed to connect to device and keep rest of app running
            Thread(Runnable {       //connect bluetooth thread
                //cancel discovery in case it was turned on
                btAdapter?.cancelDiscovery()
                try {
                    //connect the socket
                    socket.connect()
                    //run thread on UI to update socket states
                    runOnUiThread(Runnable { conStat(socket) })
                    //new thread needed to read stream and keep rest of app running
                    Thread(Runnable{        //read bluetooth thread
                        //keep reading stream as long as it is open
                        while(true) {
                            readBytes = try {
                                inStream.read(inBuffer)
                            } catch (e: IOException) {
                                Log.d("IN_STREAM: ", "input stream disconnected")
                                break
                            }
                            //return stream information to UI thread as a list view
                            runOnUiThread(Runnable {
                                data.add(inBuffer.copyOf())
                                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()
        }

        //cancel button closes the socket connection and returns to main activity
        cancelButton.setOnClickListener {
            //close socket connection
            Thread(Runnable {       //close bluetooth thread
                try {
                    socket.close()
                } catch (e: IOException) {
                    Log.i("SOCKET: ", "Could not close socket")
                }
                //return to main activity
                runOnUiThread(Runnable {
                    conStat(socket)
                    val intent = Intent(this, MainActivity::class.java)
                    startActivity(intent)
                })
            }).start()
        }

        exportButton.setOnClickListener { 
            //how to stop threads?
        }

Answer 1

强制停止线程只是一个坏主意，这就是 Thread.stop 被弃用的原因。
所以你可以使用一个标志，比如
```
val shouldContinue = AtomicBoolean(true)
```
在数据读取线程中，将"keep reading stream as long as it is open"下的while (true)替换为while (shouldContinue.get())；在取消按钮监听器中添加 shouldContinue.set(false).

使用 var shouldContinue = true 而不是 AtomicBoolean 可能有效，但不保证一定有效。因此它可能在某些设备上失败，但在您的设备或 Android 模拟器中不会失败，这将是 "fun" 调试。
使用 AsyncTask and FutureTask 代替线程可能会更好。甚至是 Kotlin 协同程序，但这可能应该留到将来使用...

Kotlin：停止内联线程

Kotlin: Stop In-Line Thread

multithreading

android

bluetooth

kotlin