在Linux中是以處理程序為單元來進行資料的配置與管理，但是基於保護目的，一個處理程序不能直接存取另一個處理程序資源。
解決方法 ：透過 IPC(Inter-Prcess Communication) 來溝通。
為了完成處理程序之間的通訊，Binder採用了AIDL來描述處理程序間的介面，讓Android得以實踐跨界傳值的目的。(跨界存取)
AIDL(Androoid Interface Definition Language)是一種介面描述語言，編譯器可以通過 .aidl 檔生成一段程式代碼，通過預先定義的介面達到兩個進程內部通訊的目的。
實作方法
IAddService.aidl
package com.aidl;
interface IAddService
{
int add(in int x, in int y);
}
AddService.java
package com.service;
import com.aidl.IAddService;
import android.app.Service;
import android.content.Intent;
import android.os.IBinder;
import android.os.RemoteException;
public class AddService extends Service
{
@Override
public IBinder onBind(Intent arg0)
{
IAddService.Stub stub = new IAddService.Stub()
{
@Override
public int add(int x, int y) throws RemoteException
{
return x+y;
}
};
return stub;
}
}
AddServiceConnection.java
AIDL(Androoid Interface Definition Language)是一種介面描述語言，編譯器可以通過 .aidl 檔生成一段程式代碼，通過預先定義的介面達到兩個進程內部通訊的目的。
實作方法
IAddService.aidl
package com.aidl;
interface IAddService
{
int add(in int x, in int y);
}
AddService.java
package com.service;
import com.aidl.IAddService;
import android.app.Service;
import android.content.Intent;
import android.os.IBinder;
import android.os.RemoteException;
public class AddService extends Service
{
@Override
public IBinder onBind(Intent arg0)
{
IAddService.Stub stub = new IAddService.Stub()
{
@Override
public int add(int x, int y) throws RemoteException
{
return x+y;
}
};
return stub;
}
}
AddServiceConnection.java
package com.service;
import com.aidl.IAddService;
import android.content.ComponentName;
import android.content.ServiceConnection;
import android.os.IBinder;
public class AddServiceConnection implements ServiceConnection
{
private IAddService service;
@Override
public void onServiceConnected(ComponentName name, IBinder service)
{
this.service = IAddService.Stub.asInterface(service);
}
@Override
public void onServiceDisconnected(ComponentName name)
{
this.service = null;
}
public IAddService getService()
{
return this.service;
}
}
AIDL_Add.java
package com.test;
import com.aidl.IAddService;
import com.service.AddServiceConnection;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
public class AIDL_Add extends Activity
{
private AddServiceConnection connection;
private EditText editText01, editText02;
private TextView textView01;
private Button button01;
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
initService();
editText01 = (EditText)findViewById(R.id.editText1);
editText02 = (EditText)findViewById(R.id.editText2);
textView01 = (TextView)findViewById(R.id.textView2);
button01 = (Button)findViewById(R.id.button1);
button01.setOnClickListener(new Button01OnClickListener());
}
private void initService()
{
connection = new AddServiceConnection();
Intent intent = new Intent("com.service.REMOTE_SERVICE");
bindService(intent, connection, Context.BIND_AUTO_CREATE);
}
class Button01OnClickListener implements OnClickListener
{
@Override
public void onClick(View view)
{
int xValue = Integer.parseInt(editText01.getText().toString());
int yValue = Integer.parseInt(editText02.getText().toString());
IAddService service = connection.getService();
try
{
if(service==null)
{
Toast.makeText(AIDL_Add.this, "Service is null", Toast.LENGTH_SHORT).show();
}
else
{
Toast.makeText(AIDL_Add.this, String.valueOf(service.add(xValue, yValue)), Toast.LENGTH_SHORT).show();
textView01.setText(String.valueOf(service.add(xValue, yValue)));
}
}
catch(Exception e)
{
e.printStackTrace();
}
}
}
}
執行結果如下：
