android应用与服务的通信之学生查询系统案例源码

1.清单文件

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="cn.caicai.appservice"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk android:minSdkVersion="8" />

    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name" >
        <activity
            android:label="@string/app_name"
            android:name=".Cai_appserviceActivity" >
            <intent-filter >
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <!--自定义服务申明 -->
        <service android:name=".studentservice"></service>
    </application>

</manifest>

2.应用界面

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="学号：" />


    <EditText
        android:id="@+id/studentid"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content" />

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:onClick="search"
        android:text="查询" />

    <TextView
        android:id="@+id/result"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

</LinearLayout>

3.服务类文件   //查询的数据可以改为从数据库调用

package cn.caicai.appservice;

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

public class studentservice extends Service {
    private String[] name = { "小白", "小王", "小软" };
    private IBinder binder=new studentbinder();
    public String query(int no) {
        if (no > 0 && no < 4) {
            return name[no - 1];
        }
        return null;
    }
    @Override
    public IBinder onBind(Intent intent) {
        return binder;
    }

    private class studentbinder extends Binder implements istudent{
        @Override
        public String querystudent(int no) {            
            return query(no);
        }
    
    }
}

4.接口文件

package cn.caicai.appservice;

public interface istudent {
 public String querystudent(int no);
}

5.应用类文件

package cn.caicai.appservice;

import android.app.Activity;
import android.content.ComponentName;
import android.content.Intent;
import android.content.ServiceConnection;
import android.os.Bundle;
import android.os.IBinder;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;

public class Cai_appserviceActivity extends Activity {

    public TextView result; //结果显示
    public EditText studentid;//学号
    private studentserviceconn conn=new studentserviceconn();//自定义服务连接对象
    private istudent studentbinder; //接口变量
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        result=   (TextView) findViewById(R.id.result);
        studentid=  (EditText) findViewById(R.id.studentid);
        Intent service=new Intent(this,studentservice.class);
        bindService(service, conn, BIND_AUTO_CREATE); //通过意图连接服务，不可用startservice启动
    }
    public void search(View v){//点击查询按钮事件
        String id=studentid.getText().toString();
        String name=studentbinder.querystudent(Integer.valueOf(id));//通过服务内部对象调用服务方法
        result.setText(name);
    }
    
    @Override
    protected void onDestroy() {
        unbindService(conn);//销毁服务连接
        super.onDestroy();
    }

    private class studentserviceconn implements ServiceConnection{

        @Override
        public void onServiceConnected(ComponentName name, IBinder service) {
            studentbinder=(istudent)service;    //获取服务内部对象        
        }

        @Override
        public void onServiceDisconnected(ComponentName name) {
            studentbinder=null;        //销毁服务内部对象
        }
        
    }
}