java Android处理程序，不在ui线程中执行post（）

Question

从一开始，我就认为Handler的方法post()和postDelayed()在与UI线程不同的线程中进行操作，我决定在其上创建一个TCPsocket，但它不起作用

我收到NetworkOnMainThreadException被抛出的消息

有没有什么方法可以执行post()和postDelayed()非UI线程中的任务

public class ServerHandler extends Handler {

private Socket serverSocket;   

public ServerHandler(){
    super(new MyHandlerThread("MyHandlerThread").getLooper());
}

@Override
public void handleMessage(Message msg) {
    super.handleMessage(msg);
}

public void connectServer()
{
    post(serverConnection);
}

public void writeMessage(String msg){
    try {
        serverSocket.getOutputStream().write(msg.getBytes());
        Log.d("MyLog","Message sent!");
    }
    catch (IOException io){
        Log.d("MyLog","SendMessage error");
    }
}

private Runnable serverConnection = new Runnable() {
    @Override
    public void run() {

        try {
            serverSocket = new Socket("152.168.21.24", 5001);

            Log.d("MyLog","Server connected!");

            while(true){
                Log.d("MyLog","Listening server");
                byte[] buffer = new byte[256];
                int bytesReceived = serverSocket.getInputStream().read(buffer);
                if(bytesReceived==-1) {
                    throw new IOException("Server disconnected");
                }
                else {
                  String msg = new String(buffer,0,bytesReceived);
                  Log.d("MyLog","Message received: " + msg);

                }
            }
        }

        catch (IOException io){
            Log.d("MyLog","Server connection error " + io.getMessage());
            connectServer();
        }
    }
};

}

Answer 1

Handler#post()在Looper线程上发布消息和可运行文件。Handler的默认构造函数将自身绑定到创建它的循环器线程。如果它不在活套线程上，那么它将抛出一个异常。因此，要在工作线程上使用处理程序，必须首先创建一个线程并使用Looper循环它。然后将给定的Looper传递给Handler的构造函数

幸运的是，已经有一个实用程序类为您完成了大部分工作。它叫HandlerThread。只要创建一个HandlerThread，并在需要线程的循环器时调用getLooper

编辑：默认处理程序构造函数不选择主线程。如果当前线程已经是活套线程，它会选择当前线程