import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.os.SystemClock;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;
import android.widget.TextView;


public class MainActivity extends AppCompatActivity {

private static final String TAG = "MainActivity";
@Override
protected void onCreate(Bundle savedInstanceState) {
    
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    final TextView textView = (TextView)findViewById(R.id.tv);

    //创建Handler
    final Handler handler = new Handler(){
        @Override
        public void handleMessage(Message msg) {
            super.handleMessage(msg);

            
            //处理消息
            Log.d(TAG,"handleMessage:"+msg.what);

            if (msg.what == 1002){
                textView.setText("imooc");
                // Log.d(TAG,"handleMessage:"+msg.arg1);

            }

        }
    };
	//这里为界面实现上的一个按钮操作
    findViewById(R.id.button).setOnClickListener(new View.OnClickListener(){
        @Override
        public void onClick(View v) {
            //有可能做大量耗时操作
            
            new Thread(new Runnable() {
                @Override
                public void run() {
                    try {
                        Thread.sleep(2000);
                    }catch (InterruptedException e){
                        e.printStackTrace();
                    }

                    
                    handler.sendEmptyMessage(1001);

                    Message message = Message.obtain();
                    message.what = 1002;
                    message.arg1 = 1003;
                    message.arg2 = 1004;
                    message.obj = MainActivity.this;

                    handler.sendMessage(message);

                    
                    handler.sendMessageAtTime(message, SystemClock.uptimeMillis()+3000);
                    handler.sendMessageDelayed(message,2000);

                    final Runnable runnable = new Runnable() {

                        @Override
                        public void run() {
                            int a = 1+2+3;
                        }
                    };
                    handler.post(runnable);

                    runnable.run();

                    handler.postDelayed(runnable,2000);

                }
            }).start();


        }
    });

    handler.sendEmptyMessage(1001);


}
}

handler.sendEmptyMessage();
handler.sendMessage();

//参数一为消息内容，参数二为发送的时间为现在的时间加3秒
handler.sendMessageAtTime(消息内容, SystemClock.uptimeMillis()+3000);

//用到sendMessage时间时为一整套的内容
代码如下：

                Message message = Message.obtain();
                message.what = 1002;
                message.arg1 = 1003;
                message.arg2 = 1004;
                message.obj = MainActivity.this;

                handler.sendMessage(message);

//一般用到handler.post()时为

handler.post(runnable);

//比如说

                   final Runnable runnable = new Runnable() {

                    @Override
                    public void run() {
                        int a = 1+2+3;
                    }
                };
                handler.post(runnable);

                runnable.run();

如此便完成了网络操作中的Handler通信以及常见的发送信息的方法。