可以使用 Android Binder 的 onTransact() 完成来完成跨进程通信

我们写一个 demo 来演示下如何使用

先来看看最后的效果图

1. 创建一个 空的 Android 项目 cn.twle.android.IPCService

2. 在 MainActivity.java 目录下新建服务端的 Service MsIPCService.java

   package cn.twle.android.ipcservice;
   
   import android.app.Service;
   import android.content.Intent;
   import android.os.Binder;
   import android.os.IBinder;
   import android.os.Parcel;
   import android.os.RemoteException;
   
   public class MsIPCService extends Service 
   {
       private static final String DESCRIPTOR = "MsIPCService";
       private final String[] names = {"Python","Perl","PHP","Java","Android"};
   
       private MsBinder mBinder = new MsBinder();
   
       private class MsBinder extends Binder {
           @Override
           protected boolean onTransact(int code, Parcel data, Parcel reply, int flags) throws RemoteException {
               switch (code){
                   case 0x001: {
                       data.enforceInterface(DESCRIPTOR);
                       int num = data.readInt();
                       reply.writeNoException();
                       reply.writeString(names[num]);
                       return true;
                   }
               }
               return super.onTransact(code, data, reply, flags);
           }
       }
   
       @Override
       public IBinder onBind(Intent intent) {
           return mBinder;
       }
   }
   

3. 修改 AndroidManifest.xml 完成 Service 注册,在 </activity> 后添加

   <!-- 配置 Service 组件,同时配置一个 action -->
   <service android:name=".MsIPCService">
       <intent-filter>
           <action android:name="cn.twle.android.ipcservice.MS_IPC_SERVICE"/>
       </intent-filter>
   </service>
   

4. 修改 activity_main.xml 添加一个 EditText 和 Button

   <?xml version="1.0" encoding="utf-8" ?>
   <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
       android:layout_width="match_parent"
       android:layout_height="match_parent"
       android:gravity="center_horizontal" 
       android:orientation="vertical" >
   
       <TextView 
           android:layout_width="match_parent"
           android:layout_height="wrap_content"
           android:text="请输入你要查询语言的序号"
       />
   
       <EditText
           android:layout_width="match_parent"
           android:layout_height="wrap_content"
           android:inputType="number" 
           android:id="@+id/lang_id" />
   
       <Button 
           android:text="查询"
           android:id="@+id/btn_search"
           android:layout_width="wrap_content" 
           android:layout_height="wrap_content" />
   
       <TextView
           android:layout_width="match_parent"
           android:layout_marginLeft="16dp"
           android:layout_height="44dp"
           android:id="@+id/search_rs"
           android:text=""
       />
   
       <TextView 
           android:layout_marginTop="16dp"
           android:layout_marginLeft="16dp"
           android:layout_width="match_parent"
           android:layout_height="wrap_content"
           android:text="0. Python\n1. Perl\n2. PHP\n3. Java\n4.Android"
       />
   
   </LinearLayout>
   

5. 修改 MainActivity.java 实现客户端

   package cn.twle.android.ipcservice;
   
   import android.content.ComponentName;
   import android.content.Intent;
   import android.content.ServiceConnection;
   import android.os.IBinder;
   import android.os.RemoteException;
   import android.support.v7.app.AppCompatActivity;
   import android.os.Bundle;
   import android.view.View;
   import android.widget.Button;
   import android.widget.EditText;
   import android.widget.TextView;
   import android.widget.Toast;
   
   public class MainActivity extends AppCompatActivity implements View.OnClickListener{
   
       private EditText lang_id;
       private Button btn_search;
       private TextView search_rs;
       private IBinder mIBinder;
       private ServiceConnection PersonConnection  = new ServiceConnection()
       {
           @Override
           public void onServiceDisconnected(ComponentName name)
           {
               mIBinder = null;
           }
   
           @Override
           public void onServiceConnected(ComponentName name, IBinder service)
           {
               mIBinder = service;
           }
       };
   
       @Override
       protected void onCreate(Bundle savedInstanceState) {
           super.onCreate(savedInstanceState);
           setContentView(R.layout.activity_main);
           bindViews();
   
           //绑定远程Service
           Intent service = new Intent(this,MsIPCService.class);
           service.setPackage("cn.twle.android.ipcservice");
           bindService(service, PersonConnection, BIND_AUTO_CREATE);
   
           btn_search.setOnClickListener(this);
       }
   
       private void bindViews() {
           lang_id = (EditText) findViewById(R.id.lang_id);
           btn_search = (Button) findViewById(R.id.btn_search);
           search_rs = (TextView) findViewById(R.id.search_rs);
       }
   
       @Override
       public void onClick(View v) {
           int num = Integer.parseInt(lang_id.getText().toString());
           if (mIBinder == null)
           {
               Toast.makeText(this, "未连接服务端或服务端被异常杀死", Toast.LENGTH_SHORT).show();
           } else {
               android.os.Parcel _data = android.os.Parcel.obtain();
               android.os.Parcel _reply = android.os.Parcel.obtain();
               String _result = null;
               try{
                   _data.writeInterfaceToken("MsIPCService");
                   _data.writeInt(num);
                   mIBinder.transact(0x001, _data, _reply, 0);
                   _reply.readException();
                   _result = _reply.readString();
                   search_rs.setText(_result);
                   lang_id.setText("");
               }catch (RemoteException e)
               {
                   e.printStackTrace();
               } finally
               {
                   _reply.recycle();
                   _data.recycle();
               }
           }
       }
   }