Android中子线程和UI线程之间通信的方式

多线程中的交互：Handler

Handler :可以发送Message,和接收Message【通过message.what = 0来设置message的类型】

Message:可以放置Bundle【用于传送基本数据类型，String和实现了Serizlizable接口的应用类型】

1、将子线程中的数据通过handler发送到了handMessage方法中

import android.app.Activity;
import android.content.Intent;
import android.os.Handler;
import android.os.Message;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
 
import java.util.ArrayList;
 
//在onCreate()方法中添加一条线程（子线程传递一个list到UI线程）
public class MainActivity extends Activity {
    private Button btn_join;
    private ArrayList<String> userList;
    Message message =new Message();
    Message message1 =new Message();
    private int temp = 0;
    Bundle bundle1 =new Bundle();
    Handler handler =new Handler(){
        //接收handler发过来的消息
        @Override
        public void handleMessage(Message msg) {
            message1 = msg;
            switch (msg.what) {
                case 1://接收message.what==1的消息
                    btn_join.setText(temp+"");
                    break;
                default:
                    break;
            }
        };
    };
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        btn_join = (Button)findViewById(R.id.button1);
        btn_join.setOnClickListener(new View.OnClickListener() {
            /**
             * 1.将实现Serializable的类User添加到ArrayList<User>的对象userList中
             * 2.intent.putExtra("Users",userList);传递
             */
            @Override
            public void onClick(View arg0) {
                Intent intent = new Intent(MainActivity.this,Secound.class);
                Bundle bundle = new Bundle();
                intent.putExtra("Users",userList);
                startActivity(intent);
            }
        });
        new Thread(new Runnable() {
            @Override
            public void run() {
                for(int i = 1;i<=10;i++){
                    try {
                        Thread.sleep(1000);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                    bundle1.putSerializable("user",userList);
                    message.setData(bundle1);//发送bundle
                    message.setTarget(handler);
                    message.what = 1;
                    handler.sendMessage(message);
                    temp++;
                }
            }
        }).start();
    }
}

2、使用Handler.post(Runnable runnable)

final Handler handler1 = new Handler();
        new Thread(){//开启子线程
            @Override
            public void run() {
                //子线程中执行
                handler1.post(new Runnable() {
                    @Override
                    public void run() {
                        //执行Ui线程
                    }
                });
            }
        }.start();

3、使用runUiThread(Runnable runnable)

new Thread(){
            @Override
            public void run() {
                //子线程中执行
               runOnUiThread(new Runnable() {
                   @Override
                   public void run() {
                       //Ui线程中执行
                   }
               });
            }
        }.start();