Android IPC机制ACtivity绑定Service通信代码实例

Binder通信过程类似于TCP/IP服务连接过程binder四大架构Server(服务器)，Client(客户端)，ServiceManager(DNS)以及Binder驱动(路由器)

其中Server，Client，ServiceManager运行于用户空间，驱动运行于内核空间。这四个角色的关系和互联网类似：Server是服务器，Client是客户终端，SMgr是域名服务器（DNS），驱动是路由器。

book.java

package com.example.android_binder_testservice;

import android.os.Parcel;
import android.os.Parcelable;

public class Book implements Parcelable {
  private String bookName;
  private String author;
  private int publishDate;

  public Book() {

  }

  public Book(String bookName, String author, int publishDate) {
    super();
    this.bookName = bookName;
    this.author = author;
    this.publishDate = publishDate;
  }

  public String getBookName() {
    return bookName;
  }

  public void setBookName(String bookName) {
    this.bookName = bookName;
  }

  public String getAuthor() {
    return author;
  }

  public void setAuthor(String author) {
    this.author = author;
  }

  public int getPublishDate() {
    return publishDate;
  }

  public void setPublishDate(int publishDate) {
    this.publishDate = publishDate;
  }

  @Override
  public int describeContents() {
    return 0;
  }

  @Override
  public void writeToParcel(Parcel out, int flags) {
    out.writeString(bookName);
    out.writeString(author);
    out.writeInt(publishDate);

  }

  public static final Parcelable.Creator<Book> CREATOR = new Creator<Book>() {
    @Override
    public Book[] newArray(int size) {
      return new Book[size];
    }

    @Override
    public Book createFromParcel(android.os.Parcel source) {
      return new Book(source);
    }
  };

  public Book(Parcel in) {
    bookName = in.readString();
    author = in.readString();
    publishDate = in.readInt();
  }
}

上面是一个 实现了parcelable的实体类，就是将book序列化，在putExtra到Service时会被写入内存加快程序速度

mainActivity.java

package com.example.android_binder_testservice;

import android.os.Bundle;
import android.util.Log;
import android.app.Activity;
import android.content.Intent;
import android.view.Menu;
import android.view.View;
import android.widget.Button;

public class MainActivity extends Activity {
  Button startServiceButton;// 启动服务按钮
  Button shutDownServiceButton;// 关闭服务按钮
  Button startBindServiceButton;// 启动绑定服务按钮
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    getWidget();
    regiestListener();
  }
  public void getWidget(){
    startServiceButton = (Button) findViewById(R.id.startService);
    startBindServiceButton = (Button) findViewById(R.id.bindService);
    shutDownServiceButton = (Button) findViewById(R.id.stopService);
  }
  public void regiestListener() {
    startServiceButton.setOnClickListener(startService);
    shutDownServiceButton.setOnClickListener(shutdownService);
    startBindServiceButton.setOnClickListener(startBinderService);
  }
  /** 启动服务的事件监听 */
  public Button.OnClickListener startService = new Button.OnClickListener() {
    public void onClick(View view) {
      /** 单击按钮时启动服务 */
      Intent intent = new Intent(MainActivity.this,
          CountService.class);
      startService(intent);

      Log.v("MainStadyServics", "start Service");
    }
  };
  /** 关闭服务 */
  public Button.OnClickListener shutdownService = new Button.OnClickListener() {
    public void onClick(View view) {
      /** 单击按钮时启动服务 */
      Intent intent = new Intent(MainActivity.this,
          CountService.class);
      /** 退出Activity是，停止服务 */
      stopService(intent);
      Log.v("MainStadyServics", "shutDown serveice");
    }
  };
  /** 打开绑定服务的Activity */
  public Button.OnClickListener startBinderService = new Button.OnClickListener() {
    public void onClick(View view) {
      /** 单击按钮时启动服务 */
      Intent intent = new Intent(MainActivity.this, UseBrider.class);
      startActivity(intent);
      Log.v("MainStadyServics", "start Binder Service");
    }
  };

}

mainActivity中当使用startService()启动Service时会调用Service的onStartCommand（）

当使用bindService（）则会调用onBind（）方法，可能会觉了看的又看怎么没看到bindService（）这个方法呢

重点在

Intent intent = new Intent(MainActivity.this, UseBrider.class);
startActivity(intent);

继续上代码

UseBrider.java

/** 通过bindService和unBindSerivce的方式启动和结束服务 */
public class UseBrider extends FragmentActivity {
  /** 参数设置 */
  CountService countService;

  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(new UseBriderFace(this));

    Intent intent = new Intent(UseBrider.this, CountService.class);
    intent.putExtra("book", new Book("name", "an", 1999));

　　　　/** 进入Activity开始服务

　　　　　* conn
　　　　　*/
    bindService(intent, conn, Context.BIND_AUTO_CREATE);

  }

  private ServiceConnection conn = new ServiceConnection() {
    /*
     * 这个方法会获取到CountService的onBind方法中返回的Binder对象
     * 然后就可以对服务进行某种操作了
     */
    public void onServiceConnected(ComponentName name, IBinder service) {
      // TODO Auto-generated method stub
      countService = ((CountService.ServiceBinder) service).getService();
      countService.callBack();
    }

    /** 无法获取到服务对象时的操作 */
    public void onServiceDisconnected(ComponentName name) {
      // TODO Auto-generated method stub
      countService = null;
    }

  };

  protected void onDestroy() {
    super.onDestroy();
    this.unbindService(conn);
    Log.v("MainStadyServics", "out");
  }
}

UseBriderFace.java

public class UseBriderFace extends View{
      /**创建参数*/
    public UseBriderFace(Context context){
      super(context);
    }
    public void onDraw(Canvas canvas){
      canvas.drawColor(Color.WHITE);//画白色背景
        /**绘制文字*/
      Paint textPaint = new Paint();
      textPaint.setColor(Color.RED);
      textPaint.setTextSize(30);
      canvas.drawText("使用绑定服务", 10, 30, textPaint);
      textPaint.setColor(Color.GREEN);
      textPaint.setTextSize(18);
      canvas.drawText("使用绑定服务后，这个Activity关闭后", 20, 60, textPaint);
      canvas.drawText("绑定的服务也会关闭", 5, 80, textPaint);

    }
  }

UseBriderFace.java类其实就是用java定义的布局可以用xml文件代替

countService.java

package com.example.android_binder_testservice;

/**引入包*/
import android.app.Service;// 服务的类
import android.os.IBinder;
import android.os.Parcel;
import android.os.RemoteException;
import android.os.Binder;
import android.content.Intent;
import android.util.Log;

/** 计数的服务 */
public class CountService extends Service {
  private String TAG = CountService.class.getSimpleName();
  /** 创建参数 */
  boolean threadDisable;
  int count;
  Book book;
/*
 * 当通过bindService()启动CountService时会调用这个方法并返回一个ServiceBinder对象
 * 这个Binder对象封装着一个CountService实例，
 * 客户端就可以通过ServiceBinder对服务端进行一些操作
 */
  public IBinder onBind(Intent intent) {
    Log.i(TAG, "onBind");
    book = intent.getParcelableExtra("book");
    return new ServiceBinder();
  }

  @Override
  public int onStartCommand(Intent intent, int flags, int startId) {
    Log.i(TAG, "onStartCommand");
    return super.onStartCommand(intent, flags, startId);
  }

  @Override
  public boolean onUnbind(Intent intent) {
    Log.i(TAG, "onUnbind");
    return super.onUnbind(intent);
  }

  @Override
  public void onRebind(Intent intent) {
    Log.i(TAG, "onRebind");
    super.onRebind(intent);
  }

  public void onCreate() {
    super.onCreate();
    /** 创建一个线程，每秒计数器加一，并在控制台进行Log输出 */
    new Thread(new Runnable() {
      public void run() {
        while (!threadDisable) {
          try {
            Thread.sleep(1000);
          } catch (InterruptedException e) {

          }
          count++;
          Log.v("CountService", "Count is" + count);
        }
      }
    }).start();
    Log.i(TAG, "onCreate");
  }

  public void onDestroy() {
    super.onDestroy();
    /** 服务停止时，终止计数进程 */
    this.threadDisable = true;
    Log.i(TAG, "onDestroy");
  }

  public int getConunt() {
    return count;
  }
  public void callBack(){
    Log.i(TAG, "hello,i am a method of CountService");
  }

  class ServiceBinder extends Binder {
    public CountService getService() {

      return CountService.this;
    }
  }
}

代码解释有了，想不出来了

源码下载地址：http://git.oschina.net/zwh_9527/Binder

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