Android Handler、Loop 的简单使用

package lib.com.myapplication;
import android.os.Bundle;
import android.os.Handler;
import android.os.Looper;
import android.os.Message;
import android.support.v7.app.AppCompatActivity;

public class MainActivity extends AppCompatActivity {

    private Handler handler1 ;
    private Handler handler2 ;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        new MyThread1().start();
        new MyThread2().start();
    }

    class MyThread1 extends Thread {

        @Override
        public void run() {
            super.run();

            Looper.prepare();

            handler1 = new Handler(){
                @Override
                public void handleMessage(Message msg) {
                    super.handleMessage(msg);
                    System.out.println( "threadName--" + Thread.currentThread().getName() + "messageWhat-"+ msg.what );
                }
            };

            try {
                sleep( 3000 );
            } catch (InterruptedException e) {
                e.printStackTrace();
            }

            handler2.sendEmptyMessage( 2 ) ;

            Looper.loop();
        }
    }

    class MyThread2 extends Thread {
        @Override
        public void run() {
            super.run();
            Looper.prepare();

            handler2 = new Handler(){
                @Override
                public void handleMessage(Message msg) {
                    super.handleMessage(msg);
                    System.out.println( "threadName--" + Thread.currentThread().getName() + "messageWhat-"+ msg.what );
                }
            };

            try {
                sleep( 4000 );
            } catch (InterruptedException e) {
                e.printStackTrace();
            }

            handler1.sendEmptyMessage( 5 ) ;

            Looper.loop();
        }
    }
}