android中aidl

清疚 2023-01-03 04:19 151阅读 0赞

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AIDL是一个缩写，全称是Android Interface Definition Language，也就是Android接口定义语言.  
设计这门语言的目的是为了实现进程间通信，尤其是在涉及多进程并发情况下的进程间通信。  
学习这个是在Service的远程服务调用时会遇到这个问题。

service的调用分本地调用和远程服务调用。本地其实就是同一个应用之间的调用，远程服务调用就是不同应用之间的调用。比如淘宝里的芭芭农场调用支付宝里的芭芭农场，是两个应用之间的调用。

案例：  
客户端  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2h1YW5nYmFva2FuZw_size_16_color_FFFFFF_t_70]

服务端，由于是暴露服务，是不用界面的，只要编写好AIDL文件，拷贝一份到客户端，就可以进行调用了。在我们的服务端项目中，同时演示了调用本地的Service  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2h1YW5nYmFva2FuZw_size_16_color_FFFFFF_t_70 1]

处理MainActivity.java

package com.hbk.servicedemo;
    
    import android.app.Activity;
    import android.content.ComponentName;
    import android.content.Context;
    import android.content.Intent;
    import android.content.ServiceConnection;
    import android.os.Bundle;
    import android.os.IBinder;
    import android.util.Log;
    import android.view.View;
    import android.widget.Toast;
    
    import com.hbk.servicedemo.local.MyService;
    
    public class MainActivity extends Activity { 
    
    	@Override
    	protected void onCreate(Bundle savedInstanceState) { 
    		super.onCreate(savedInstanceState);
    		setContentView(R.layout.activity_main);
    	}
    	
    	//启动服务
    	public void startMyService(View v) { 
    		Intent intent = new Intent(this, MyService.class);
    		startService(intent);
    		Toast.makeText(this, "start service", 0).show();
    	}
    	
    	public void stopMyService(View v) { 
    		Intent intent = new Intent(this, MyService.class);
    		stopService(intent);
    		Toast.makeText(this, "stop service", 0).show();
    	}
    	
    	private ServiceConnection conn;
    	//绑定服务
    	public void bindMyService(View v) { 
    		Intent intent = new Intent(this, MyService.class);
    		//创建连接对象
    		if(conn==null) { 
    			conn = new ServiceConnection() { 
    				@Override
    				public void onServiceDisconnected(ComponentName name) { 
    					Log.e("TAG", "onServiceDisconnected()");
    				}
    				@Override
    				public void onServiceConnected(ComponentName name, IBinder service) { 
    					Log.e("TAG", "onServiceConnected()");
    				}
    			};
    			//绑定Service
    			bindService(intent, conn, Context.BIND_AUTO_CREATE);
    			
    			Toast.makeText(this, "bind service", 0).show();
    		} else { 
    			Toast.makeText(this, "已经bindservice", 0).show();
    		}
    		
    	}
    	
    	//解绑服务
    	public void unbindMyService(View v) { 
    		if(conn!=null) { 
    			unbindService(conn);
    			conn = null;
    			Toast.makeText(this, "unbind service", 0).show();
    		} else { 
    			Toast.makeText(this, "还没有bindservice", 0).show();
    		}
    		
    	}
    	
    	//在Activity死亡之前调用
    	@Override
    	protected void onDestroy() { 
    		super.onDestroy();
    		if(conn!=null) { 
    			unbindService(conn);
    			conn = null;
    		}
    	}
    }

本地Service,主要重点掌握如下API即可  
.startService(Intent service)  
stopService(Intent name)  
bindService(Intent service, ServiceConnection conn, int flags)  
unbindService(ServiceConnection conn)

远程Service,先定义AIDL文件，如我们新建IStudentService.aidl(可以新建interface，然后重命名)  
IStudentService.aidl，同包下的类也需要import(注意)

package com.hbk.servicedemo.remote;
    import com.hbk.servicedemo.remote.Student;
    interface IStudentService { 
    
    	 Student getStudentById(int id);
    }

第二步，实体类需要实现Parcelable接口  
Student.java

package com.hbk.servicedemo.remote;
    
    import android.os.Parcel;
    import android.os.Parcelable;
    import android.util.Log;
    
    public class Student implements Parcelable { 
    	private int id;
    	private String name;
    	private double price;
    
    	public int getId() { 
    		return id;
    	}
    
    	public void setId(int id) { 
    		this.id = id;
    	}
    
    	public String getName() { 
    		return name;
    	}
    
    	public void setName(String name) { 
    		this.name = name;
    	}
    
    	public double getPrice() { 
    		return price;
    	}
    
    	public void setPrice(double price) { 
    		this.price = price;
    	}
    
    	@Override
    	public String toString() { 
    		return "Student [id=" + id + ", name=" + name + ", price=" + price + "]";
    	}
    
    	public Student(int id, String name, double price) { 
    		super();
    		this.id = id;
    		this.name = name;
    		this.price = price;
    	}
    
    	public Student() { 
    		super();
    		// TODO Auto-generated constructor stub
    	}
    
    	@Override
    	public int describeContents() { 
    		return 0;
    	}
    
    	@Override
    	public void writeToParcel(Parcel dest, int flags) { 
    		Log.e("TAG", "打包 writeToParcel()");
    		dest.writeInt(id);
    		dest.writeString(name);
    		dest.writeDouble(price);
    	}
    
    	// 添加一个静态成员,名为CREATOR,该对象实现了Parcelable.Creator接口
    	public static final Parcelable.Creator<Student> CREATOR = new Parcelable.Creator<Student>() { 
    
    		@Override
    		public Student createFromParcel(Parcel source) { 
    			// id
    			int id = source.readInt();
    			// name
    			String name = source.readString();
    			// price
    			double price = source.readDouble();
    			return new Student(id, name, price);
    		}
    
    		@Override
    		public Student[] newArray(int size) { 
    			return new Student[size];
    		}
    
    	};
    }

固定模式，`public static final Parcelable.Creator<Student> CREATOR`，名字一定叫CREATOR，注意序列化的顺序，即打包读写顺序要一致。  
第三步，新建Student.aidl文件

package com.hbk.servicedemo.remote;
    parcelable Student;

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2h1YW5nYmFva2FuZw_size_16_color_FFFFFF_t_70 2]  
清单文件中注册service

定义Action，主要是为了给客户端进行调用  
客户端处理Activity

package com.hbk.servicedemoclient;
    
    import android.app.Activity;
    import android.content.ComponentName;
    import android.content.Context;
    import android.content.Intent;
    import android.content.ServiceConnection;
    import android.os.Bundle;
    import android.os.IBinder;
    import android.os.RemoteException;
    import android.util.Log;
    import android.view.View;
    import android.widget.EditText;
    import android.widget.Toast;
    
    import com.hbk.servicedemo.remote.IStudentService;
    import com.hbk.servicedemo.remote.Student;
    
    public class MainActivity extends Activity { 
    	private EditText et_aidl_id; 
    	
    	@Override
    	protected void onCreate(Bundle savedInstanceState) { 
    		super.onCreate(savedInstanceState);
    		setContentView(R.layout.activity_main);
    		et_aidl_id = (EditText) findViewById(R.id.et_aidl_id);
    	}
    	
    	private ServiceConnection conn;
    	private IStudentService studentService;
    	// 绑定远程服务
    	public void bindRemoteService(View v){ 
    		Intent intent = new Intent("com.hbk.servicedemo.remote.MyRemoteService.Action");
    		if(conn == null){ 
    			conn = new ServiceConnection() { 
    				
    				@Override
    				public void onServiceDisconnected(ComponentName name) { 
    					// TODO Auto-generated method stub
    					
    				}
    				
    				@Override
    				public void onServiceConnected(ComponentName name, IBinder service) { 
    					Log.e("TAG", "onServiceConnected()");
    					studentService = IStudentService.Stub.asInterface(service);
    				}
    			};
    			bindService(intent, conn, Context.BIND_AUTO_CREATE);
    			Toast.makeText(this, "绑定Service", 0).show();
    		}
    	}
    	
    	public void invokeRemote(View v) throws RemoteException { 
    		if(studentService!=null) { 
    			int id = Integer.parseInt(et_aidl_id.getText().toString());
    			Student student = studentService.getStudentById(id);
    			Toast.makeText(this, student.toString(), 0).show();
    		}
    	}
    	
    	public void unbindRemoteService(View v) { 
    		if (conn != null) { 
    			unbindService(conn);
    			conn = null;
    			studentService = null;
    			Toast.makeText(this, "解绑Service", 0).show();
    		} else { 
    			Toast.makeText(this, "还未绑定Service", 0).show();
    		}
    	}
    }

绑定的时候，传入服务端的action  
Intent intent = new Intent(“com.hbk.servicedemo.remote.MyRemoteService.Action”);  
服务连接的时候，初始化业务服务

@Override
    public void onServiceConnected(ComponentName name, IBinder service) { 
    	Log.e("TAG", "onServiceConnected()");
    	studentService = IStudentService.Stub.asInterface(service);
    }

测试  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2h1YW5nYmFva2FuZw_size_16_color_FFFFFF_t_70 3]

[Link 1]: https://www.captainai.net/flyop007/
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2h1YW5nYmFva2FuZw_size_16_color_FFFFFF_t_70]: /images/20221119/5259488e97284f96a3f5bd3939872c3a.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2h1YW5nYmFva2FuZw_size_16_color_FFFFFF_t_70 1]: /images/20221119/99ea4b6d60f24353b785f24196b8ea1f.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2h1YW5nYmFva2FuZw_size_16_color_FFFFFF_t_70 2]: /images/20221119/191cef1b58fc46f4b14ca2a53d692864.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2h1YW5nYmFva2FuZw_size_16_color_FFFFFF_t_70 3]: /images/20221119/45d53d86851d48a0ac9d691fe3228621.png