一般來說，Activity呼叫Service 分為兩種：程序內呼叫和程序間呼叫。程序內呼叫時比較常用的一種，在程序內呼叫中我們常常使用的是bindService來啟動Service（關於這種啟動方式的好處，才疏學淺就不再這賣弄了）。下面就這兩種呼叫方式分別進行簡單介紹：

1.通過bindService來啟動Service，並呼叫Service中的方法。

1.一個簡單的Service：

package gu.chuan.hang;

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

public class MyService extends Service {

    @Override
    public IBinder onBind(Intent intent) {
        // TODO Auto-generated method stub
        return new MyBinder();
    }

    public class MyBinder extends Binder{
        public MyService getMyService(){
            return
 
 MyService.this;
        }
    }
    /**
     * 在Service中定義這個方法，用於測試
     * @return
     */
    public String getAuthorName(){
        return "guchuanhang";
    }
}

2.在Activity中繫結Service並測試效果：

package gu.chuan.hang;

import android.app.Activity;
import android.content.ComponentName;
import android.content.Context;
import
 
 android.content.Intent;
import android.content.ServiceConnection;
import android.os.Bundle;
import android.os.IBinder;
import android.widget.Toast;

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        Intent myServiceIntent = new Intent(MainActivity.this, MyService.class);
        bindService(myServiceIntent, mServiceConnection,
                Context.BIND_AUTO_CREATE);
    }

    ServiceConnection mServiceConnection = new ServiceConnection() {
        @Override
        public void onServiceConnected(ComponentName name, IBinder service) {
            MyService myService = ((MyService.MyBinder) service).getMyService();
            String authorName = myService.getAuthorName();
            Toast.makeText(MainActivity.this, "author name is: " + authorName,
                    Toast.LENGTH_LONG).show();
        }

        @Override
        public void onServiceDisconnected(ComponentName name) {
        }

    };
}

3.截個圖吧，更清楚一點：

2.程序間啟動Service並呼叫Service中的方法

1.首先定義一個aidl檔案（副檔名為.aidl）：

package gu.chuan.hang.remoteservice.aidl;
interface AuthorInfo{
 String getAuthorName();
}

2.定義一個實現了aidl的服務：

package gu.chuan.hang.remoteservice.aidl;

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

public class MyService extends Service{

    @Override
    public IBinder onBind(Intent intent) {
        return new MyStub();
    }
    private class MyStub extends AuthorInfo.Stub{

        @Override
        public String getAuthorName() throws RemoteException {
            return "guchuanhang";
        }

    }


}

3.在同一個app中模擬程序間呼叫的效果，給Service設定remote屬性：

<service android:name="gu.chuan.hang.remoteservice.aidl.MyService"
            android:process=":remote"
            android:exported="false" 
            >
        </service>

4.啟動並呼叫Service中的方法：

public class MainActivity extends Activity {
       @Override
       public void onCreate(Bundle savedInstanceState){
           super.onCreate(savedInstanceState);
           Intent intent=new Intent(this,MyService.class);
           startService(intent);
           bindService(intent, mServiceConnection, Context.BIND_AUTO_CREATE);
       } 

       private ServiceConnection  mServiceConnection=new ServiceConnection(){
        @Override
        public void onServiceConnected(ComponentName name, IBinder service) {
            AuthorInfo authorInfo=AuthorInfo.Stub.asInterface(service);
            try {
                String authorName=authorInfo.getAuthorName();
            Toast.makeText(MainActivity.this, "author name is: "+authorName, Toast.LENGTH_LONG).show();
            } catch (RemoteException e) {
                e.printStackTrace();
            }



        }
        @Override
        public void onServiceDisconnected(ComponentName name) {
        }
       };

}

3.附上Demo下載地址：