处理信息Message-Handler

package com.hanqi.zuoye;

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

import java.util.Random;

public class xianchengActivity extends AppCompatActivity {

    Button bt, b1,b2,b3;
    TextView tv ,tv2;

    Random r=new Random();
    //定义Handler
       Handler h=new Handler(){
        @Override
        public void handleMessage(Message msg) {
            super.handleMessage(msg);
            //处理消息
            if(msg.what==1){
                String str = msg.obj.toString();
                tv.setText("+"+str+"+");
            }
            if(msg.what==2){
                tv.setText("这是空消息");
            }
        }
    };
    int ii=10;
    Handler h2=new Handler(){
        @Override
        public void handleMessage(Message msg) {
            super.handleMessage(msg);
            switch (msg.what){
                case 1:
                    if(ii==20){
                        return;
                    }
                    ii++;
                    tv2.setText(ii+"");
                    //继续发送消息
                    h2.sendEmptyMessageDelayed(1, 1000);
                    h2.removeMessages(2);
                    break;
                case 2:
                    if(ii==1){return;}
                    ii--;
                    tv2.setText(ii + "");
                    //继续发送消息
                    h2.sendEmptyMessageDelayed(2, 1000);
                    h2.removeMessages(1);
                    break;
                case 3:
                    h2.removeMessages(1);
                   h2.removeMessages(2);
                    break;
            }
        }
    };
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_xiancheng);
        bt=(Button)findViewById(R.id.bt);
        b1=(Button)findViewById(R.id.b1);
        b2=(Button)findViewById(R.id.b2);
        b3=(Button)findViewById(R.id.b3);
        tv=(TextView)findViewById(R.id.tv);
        tv2=(TextView)findViewById(R.id.tv2);
    }

    public void bt1(View v){
        for( int i=0;i<10;i++){

            new Thread(

            ){
                @Override
                public void run() {
                    try {
                        Thread.sleep(r.nextInt(1000));
                       }
                    catch (Exception e){

                    }
                    runOnUiThread(new Runnable() {
                        @Override
                        public void run() {
                            bt.setText("城市1");
                        }
                    });

                    return;
                }
            }.start();
            new Thread(){
                @Override
                public void run() {

                    try {
                        Thread.sleep(r.nextInt(1000));
                    }
                    catch (Exception e){

                    } runOnUiThread(new Runnable() {
                        @Override
                        public void run() {
                            bt.setText("城市2");
                        }
                    });

                    return;
                }
            }.start();
        }
    }
    public void bt2(View v){
        //启动线程
        new Thread(
        ){
            @Override
            public void run() {
                //发送消息
                //创建Message
                Message m = Message.obtain();
                m.what=1;//id
                m.obj="我传递的信息";

                //发送即时消息
                h.sendMessage(m);
                m = Message.obtain();
                m.what=1;//id
                m.obj="我传递的信息2";

                //发送延时消息
                h.sendMessageDelayed(m,3000);

                //发送空消息
                //只发送一个what，用于判断，无需message实例
                h.sendEmptyMessage(2);

                //延时空消息
                h.sendEmptyMessageDelayed(2,3000);

            }
        }.start();
    }
    public void bt3(View v){
        //if(v.getId()==R.id.b1){}
        switch (v.getId()){
            case  R.id.b1:
                //发送消息
                h2.sendEmptyMessage(1);


               b1.setEnabled(false);
                b2.setEnabled(true);
                b3.setEnabled(true);
                if(ii==20){
                    b1.setEnabled(false);
                    b3.setEnabled(false);
                }
                break;

            case  R.id.b2:
                //发送消息
                h2.sendEmptyMessage(2);

                b1.setEnabled(true);
                b2.setEnabled(false);
                b3.setEnabled(true);
                if(ii==1){
                    b2.setEnabled(false);
                    b3.setEnabled(false);
                }
                break;
            case  R.id.b3:
                //发送消息
                h2.sendEmptyMessage(3);

                b1.setEnabled(true);
                b2.setEnabled(true);
                b3.setEnabled(false);
                break;
        }

    }
}