旺仔练习：service的普通方式和绑定方式的启动和停止（解绑出现异常，尚未解决）

package com.hanqi.dianhuabohaoqi;

import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.ServiceConnection;
import android.os.IBinder;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

public class usingservice extends AppCompatActivity {
    Button bt_1,bt_2,bt_3,bt_4;
    Intent intentservice;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_usingservice);
        bt_1=(Button)findViewById(R.id.bt_1);
        bt_2=(Button)findViewById(R.id.bt_2);
        bt_3=(Button)findViewById(R.id.bt_3);
        bt_4=(Button)findViewById(R.id.bt_4);
        bt_1.setOnClickListener(new start_service());
        bt_2.setOnClickListener(new start_service());
        bt_3.setOnClickListener(new start_service());
        bt_4.setOnClickListener(new start_service());
        intentservice=new Intent(this,EchoService.class);

    }
   class start_service implements View.OnClickListener
   {
       ServiceConnection sc;
       public void onClick(View v)
       {
           if (sc==null){
               sc= new ServiceConnection() {
                   @Override
                   public void onServiceConnected(ComponentName name, IBinder service) {
                       //接收代理对象进行强转
                       EchoService.MyBind echo=(EchoService.MyBind)service;

                       Toast.makeText(usingservice.this, "绑定service成功连接，接收返回对象="+echo.gettest(), Toast.LENGTH_SHORT).show();
                   }

                   @Override
                   public void onServiceDisconnected(ComponentName name) {

                   }
               };
           }

           switch (v.getId())
           {
               case R.id.bt_1://启动service
                   startService(intentservice);
                   break;
               case R.id.bt_2://停止service
                   stopService(intentservice);
                   break;
               case R.id.bt_3://绑定方式启动service
                   bindService(intentservice,sc , Context.BIND_AUTO_CREATE);
                   break;
               case R.id.bt_4://解除绑定
                   if (sc!=null){
                   unbindService(sc);
                       sc=null;
                   }else
                   {
                       Toast.makeText(usingservice.this, "清先绑定服务", Toast.LENGTH_SHORT).show();
                   }
                   break;
           }
       }
   }
}

package com.hanqi.dianhuabohaoqi;

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

public class EchoService extends Service {
    public EchoService() {
        Log.e("TAG","service被构造");
    }


    @Override
    public void onCreate() {
        Log.e("TAG","启动service");
        super.onCreate();
    }

    @Override
    public void onDestroy() {
        Log.e("TAG","停止service");
        super.onDestroy();
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        Log.e("TAG","onStartCommand被调用");
        return super.onStartCommand(intent, flags, startId);
    }
    @Override
    public boolean onUnbind(Intent intent) {
        Log.e("TAG","onUnbind被调用");
        return super.onUnbind(intent);
    }
    //内部类
    public class MyBind extends Binder
    {
      //定义数据交互的方法
        public int gettest()
        {
            return 123;
        }
    };

    @Override
    public IBinder onBind(Intent intent) {
        Log.e("TAG","onBind被调用");
       // throw new UnsupportedOperationException("Not yet implemented");
        return new MyBind();

    }
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context="com.hanqi.dianhuabohaoqi.usingservice">
    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/bt_1"
        android:text="启动service"/>
    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/bt_2"
        android:text="停止service"/>
    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/bt_3"
        android:text="绑定service"/>
    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/bt_4"
        android:text="解除绑定service"/>

</LinearLayout>