Android在单独的线程上执行BluetoothAdapter.LeScanCallback [英] Android execute BluetoothAdapter.LeScanCallback on seperate thread

问题描述

在Android中，BluetoothAdapter.LeScanCallback在主线程上运行。

In Android, BluetoothAdapter.LeScanCallback runs on main thread.

private BluetoothAdapter.LeScanCallback mLeScanCallback =
        new BluetoothAdapter.LeScanCallback() {
            @Override
            public void onLeScan(final BluetoothDevice device, final int rssi, byte[] scanRecord) {
                //The code here is executed on main thread
                Log.e("LeScanCallback", Thread.currentThread().getName());//Prints main
            }
        };

我可以通过执行以下操作使代码在独立线程上运行：

I can make the code run on a seperate thread by doing the following:

private BluetoothAdapter.LeScanCallback mLeScanCallback =
            new BluetoothAdapter.LeScanCallback() {
                @Override
                public void onLeScan(final BluetoothDevice device, final int rssi, byte[] scanRecord) {
                    new Thread(new Runnable() {
                        @Override
                        public void run() {
                            //The code here is executed on on new thread everytime 
                            Log.e("LeScanCallback", Thread.currentThread().getName());//Prints Thread-xxxx
                        }
                    }).start();
                }
            };

但是这会为每个回调创建一个新的线程。我想要回调中的代码在不是主线程的单个线程上运行。

But this creates a new thread for every callback. I want the code inside the callback to run on one single thread that is not the main thread. What is the right way of doing this?

推荐答案

您可以创建一个线程和looper：

You can create a thread and looper:

import android.os.Looper;
import android.os.Handler;
public class LooperThread extends Thread {
       public Handler handler;
       public void run(){
            Looper.prepare();
            handler = new Handler();
            looper.loop(); 
            /*
                 if you want to stop thread you can create you own exception, throw it and catch. Example: 
                 try
                 {
                       looper.loop();
                 } catch(MyException e){

                 }
                 And now thread is stopping (and not handling runnables from handler.post()
                 In other thread write this: 
                 thread.handler.post(new Runnable(){
                          throw new MyException(); // And now exception will be caught and thread will be stopping.
                 });
            */
       }
}



private BluetoothAdapter.LeScanCallback mLeScanCallback =
            new BluetoothAdapter.LeScanCallback() {
                private LooperThread thread = new LooperThread();
                {
                      thread.start(); // start thread once
                }
                @Override
                public void onLeScan(final BluetoothDevice device, final int rssi, byte[] scanRecord) {
                    if(thread.handler != null)
                        thread.handler.post(new Runnable() {
                        @Override
                        public void run() {
                            // And now this code is running on seperate thread. (Not creating new)
                            Log.e("LeScanCallback", Thread.currentThread().getName());//Prints Thread-xxxx
                        }
                    });
                }
            };   

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