Android学习笔记之Service

Posted 2020-06-17

与服务通信

用bindservice

而startservice并无通信条件.

service 为android为系统服务，所以程序员无法new出来，只能建立服务，共其他组件使用。

package com.jiahemeikang.helloandroid;

import com.jiahemikang.service.EchoService;
import com.jiahemikang.service.EchoService.EchoServiceBingder;

import android.os.Bundle;
import android.os.IBinder;
import android.app.Activity;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.ServiceConnection;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;

public class MainActivity extends Activity implements OnClickListener,ServiceConnection{

    private TextView tvResult ;
    private Intent serviceIntent;
    private Button btnStarAty1; 
    private Button btnStarService; 
    private Button btnStopService; 
    
    private Button btnBingService; 
    private Button btnUnBingService;
    private Button btnGetNum;
    public EchoService echoService = null;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        serviceIntent = new Intent(this,EchoService.class);
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        tvResult = (TextView)findViewById(R.id.tvResult);
        
        btnStarAty1= (Button)findViewById(R.id.btnStartAty1);
        btnStarService= (Button)findViewById(R.id.btnStartService);
        btnStopService= (Button)findViewById(R.id.btnStopService);
        
        btnStarService.setOnClickListener(this);
        btnStopService.setOnClickListener(this);
        
        
        btnBingService= (Button)findViewById(R.id.bingdingservice);
        btnUnBingService= (Button)findViewById(R.id.unbingdingservice);
        btnBingService.setOnClickListener(this);
        btnUnBingService.setOnClickListener(this);
        
        btnGetNum= (Button)findViewById(R.id.btnGetNum);
        btnGetNum.setOnClickListener(this);
        
        btnStarAty1.setOnClickListener(new View.OnClickListener(){
            @Override
            public void onClick(View v){
                
                Intent i = new Intent(MainActivity.this,Aty1.class);
                i.putExtra("txt","Hello aty1");
                startActivity(i);
                startActivityForResult(i,0);
            }
        });
        
    }

    @Override
    protected void onActivityResult(int a,int b ,Intent i){
        
        if (i!=null) {
            String result = i.getStringExtra("result");
            
            tvResult.setText(result);
        }
    }
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    @Override
    public void onClick(View v) {
        // TODO Auto-generated method stub
        switch (v.getId()) {
        case R.id.btnStartService:
            startService(serviceIntent);
            break;
        case R.id.btnStopService:
            stopService(serviceIntent);
            break;
        case R.id.bingdingservice:
            bindService(serviceIntent,this,Context.BIND_AUTO_CREATE);
            break;
        case R.id.unbingdingservice:
            unbindService(this);
            echoService =null;
            break;
        case R.id.btnGetNum:
            if (echoService!=null) {
                System.out.print("当前服务的 数字为"+echoService.getCountNum());
            }
            break;
        default:
            break;
        }
    }

    
    @Override
    public void onServiceConnected(ComponentName arg0, IBinder binder) {
        System.out.println("onServiceConnected");
        echoService = ((EchoService.EchoServiceBingder)binder).getService();
        
    }

    @Override
    public void onServiceDisconnected(ComponentName arg0) {
        // TODO Auto-generated method stub
        
    }
    
    
    
    //onStart

}

服务代码

package com.jiahemikang.service;

import java.util.Timer;
import java.util.TimerTask;

import android.app.Service;
import android.content.Intent;
import android.os.Binder;
import android.os.IBinder;

public class EchoService extends Service {

    public EchoService() {
        
    }

    @Override
    public IBinder onBind(Intent arg0) {
        System.out.println("onBind");
        return echoServiceBingder;
    }
    
    private Timer timer = null;
    private TimerTask task = null;
    
    public void startTimer(){
        if(timer ==null){
            
            timer = new Timer();
            task = new TimerTask(){

                @Override
                public void run() {
                    // TODO Auto-generated method stub
                    i++;
                    System.out.println("-"+i+"-");
                }};
                timer.schedule(task,1000,1000);
        }
    }
    private int i =0;
    public void StopTimer(){
        if (timer!=null) {
            timer.cancel();
            task.cancel();
            timer =null;
            task =null;
        }
    }
    
    public int getCountNum(){
        return i;
    }
    private final EchoServiceBingder echoServiceBingder = new EchoServiceBingder();
    public class EchoServiceBingder extends Binder{
        public EchoService getService(){
            return EchoService.this;
        }
    }
    
    @Override
    public void onCreate(){
        System.out.println("onCreate");
        startTimer();
        super.onCreate();
    }

    @Override
    public void onDestroy(){
        System.out.println("onDestroy");
        StopTimer();
        super.onDestroy();
        
    }
}