java - Android 多线程

Question

我正在尝试制作一个连接到服务器的 Android 应用程序(通过 Socket)，并且我相信我需要在不同的线程中执行此操作。但是，显然，我无法从另一个线程访问或修改 Android UI。我该怎么办？

package me.nrubin29.quiz.student;

import android.app.Activity;
import android.widget.Toast;

import java.io.EOFException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.net.Socket;

public class Connection {

    private Socket socket;
    private Thread reader;
    private ObjectInputStream inputStream;
    private ObjectOutputStream outputStream;

    public void initConnection(final Activity activity, final String ip, final String port, final String name) {
        new Thread(new Runnable() {
            public void run() {
                try {
                    Toast.makeText(activity.getApplicationContext(), "Starting connection to " + ip + ":" + Integer.parseInt(port), Toast.LENGTH_SHORT).show();

                    socket = new Socket(ip, Integer.parseInt(port));

                    Toast.makeText(activity.getApplicationContext(), "Connected!", Toast.LENGTH_SHORT).show();

                    outputStream = new ObjectOutputStream(socket.getOutputStream());

                    inputStream = new ObjectInputStream(socket.getInputStream());

                    outputStream.writeObject(name);

                    reader = new Thread(new Runnable() {
                        public void run() {
                            while (true) {
                                try {
                                    Object in = inputStream.readObject();
                                    System.out.println(in);
                                }
                                catch (EOFException e) { Toast.makeText(activity.getApplicationContext(), e.getMessage(), Toast.LENGTH_SHORT).show(); }
                                catch (Exception e) { e.printStackTrace(); }
                            }
                        }
                    });

                    reader.start();
                }
                catch (Exception e) { e.printStackTrace(); }
            }
        }).start();
    }
}

Answer 1

您可以使用runOnUiThread

activity.runOnUiThread(new Runnable() //run on ui thread
{
   @Override
   public void run() 
   { 
              // update ui
   }
});

http://developer.android.com/reference/android/app/Activity.html#runOnUiThread(java.lang.Runnable)

public final void runOnUiThread (Runnable action)

Added in API level 1
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.

Parameters
action  the action to run on the UI thread