Android组件间交互

四大组件相信大家都不陌生了吧，今天咱们就组件间通信做个说明：

首先：

　　主要今天的目的是为了说明Android 提供的一个ResultReceiver类，这个类相信大家都不陌生吧》？但是你们层深入了解过么，这个类不可谓不强大，辣么，咱们就看看怎么使他吧，

　　实例：Activity和service通信，484很屌，我也这么觉得，然并卵。

　　这里直接就来源码看看吧！！！！

　　牛逼的不行不行，

 /*
  * Copyright (C) 2009 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 package android.os;

 import com.android.internal.os.IResultReceiver;

 /**
  * Generic interface for receiving a callback result from someone.  Use this
  * by creating a subclass and implement {@link #onReceiveResult}, which you can
  * then pass to others and send through IPC, and receive results they
  * supply with {@link #send}.
  */
 public class ResultReceiver implements Parcelable {
     final boolean mLocal;
     final Handler mHandler;

     IResultReceiver mReceiver;

     class MyRunnable implements Runnable {
         final int mResultCode;
         final Bundle mResultData;

         MyRunnable(int resultCode, Bundle resultData) {
             mResultCode = resultCode;
             mResultData = resultData;
         }

         public void run() {
             onReceiveResult(mResultCode, mResultData);
         }
     }

     class MyResultReceiver extends IResultReceiver.Stub {
         public void send(int resultCode, Bundle resultData) {
             if (mHandler != null) {
                 mHandler.post(new MyRunnable(resultCode, resultData));
             } else {
                 onReceiveResult(resultCode, resultData);
             }
         }
     }

     /**
      * Create a new ResultReceive to receive results.  Your
      * {@link #onReceiveResult} method will be called from the thread running
      * <var>handler</var> if given, or from an arbitrary thread if null.
      */
     public ResultReceiver(Handler handler) {
         mLocal = true;
         mHandler = handler;
     }

     /**
      * Deliver a result to this receiver.  Will call {@link #onReceiveResult},
      * always asynchronously if the receiver has supplied a Handler in which
      * to dispatch the result.
      * @param resultCode Arbitrary result code to deliver, as defined by you.
      * @param resultData Any additional data provided by you.
      */
     public void send(int resultCode, Bundle resultData) {
         if (mLocal) {
             if (mHandler != null) {
                 mHandler.post(new MyRunnable(resultCode, resultData));
             } else {
                 onReceiveResult(resultCode, resultData);
             }
             return;
         }

         if (mReceiver != null) {
             try {
                 mReceiver.send(resultCode, resultData);
             } catch (RemoteException e) {
             }
         }
     }

     /**
      * Override to receive results delivered to this object.
      *
      * @param resultCode Arbitrary result code delivered by the sender, as
      * defined by the sender.
      * @param resultData Any additional data provided by the sender.
      */
     protected void onReceiveResult(int resultCode, Bundle resultData) {
     }

     public int describeContents() {
         return 0;
     }

     public void writeToParcel(Parcel out, int flags) {
         synchronized (this) {
             if (mReceiver == null) {
                 mReceiver = new MyResultReceiver();
             }
             out.writeStrongBinder(mReceiver.asBinder());
         }
     }

     ResultReceiver(Parcel in) {
         mLocal = false;
         mHandler = null;
         mReceiver = IResultReceiver.Stub.asInterface(in.readStrongBinder());
     }

     public static final Parcelable.Creator<ResultReceiver> CREATOR
             = new Parcelable.Creator<ResultReceiver>() {
         public ResultReceiver createFromParcel(Parcel in) {
             return new ResultReceiver(in);
         }
         public ResultReceiver[] newArray(int size) {
             return new ResultReceiver[size];
         }
     };
 }

　　

　　Line27：说明该类是Parcelable的SubClass，这就为我们今天Service和Act通信提供的可能

　　Bundle是Android通信中参数的载体，同时提供了各种各样的set方法，其中主要的一个set方法，可以接受一个Parcelable子类对象。

　　

　　不到大家注意了木；

　　Line99：protected void onReceiveResult(int resultCode, Bundle resultData)这个方法是个空实现，纳尼问题来了，咱们阔以重载了他么，

　　下边是我自己的代码，来看俺的风骚；

 import android.os.Bundle;
 import android.os.Handler;
 import android.os.ResultReceiver;

 /**
  * @author ArMn
  *    859686819@qq.com
  */
 public class MyResultReceiver extends ResultReceiver
 {

     public MyResultReceiver(Handler handler) {
         super(handler);
         // TODO Auto-generated constructor stub
     }

     @Override
     protected void onReceiveResult(int resultCode, Bundle resultData) {
         // TODO Auto-generated method stub
         if(null != mActCallBackListener)
             mActCallBackListener.callBack();
     }

     public void setReceiver(ActCallBackListener listener){
         this.mActCallBackListener = listener;
     }

     private ActCallBackListener mActCallBackListener = null;

     public interface ActCallBackListener{
         void callBack();
     }
 }

　　代码实现了ResultRecceview类，然后重载了onReceiveResult方法，同事自定义了内部interface，setReceiver方法用于指定所需要的回调对象，callback就是真正的回调方法了。

　　现在是时候说怎么通信了 ，通信的简单代码我就不再复述了，上边说道Bundle可以接受一个Parcelable对象，当然了现在咱们的MyReceiver继承自Receiver，同事Receiver是Parcelable的子类，别的就不用说了，new MyREceiver给Bundle是没问题了，回头继续源码Line74方法send方法；

　　核心源码：

 public void send(int resultCode, Bundle resultData) {
             if (mLocal) {
                 if (mHandler != null) {
                     mHandler.post(new MyRunnable(resultCode, resultData));
                 } else {
                     onReceiveResult(resultCode, resultData);
                 }
                 return;
             }
          .........
         }

　　Line6：大家可以看到这里callback到咱们重载的方法onReceiveResul方法，咱们的callback484真的就完成了回调了哪？？？？？

　　饿死人了，粢饭！！！！！！

　　有空继续吹，今天先到这<><><><><><><><><>66666666666666666