android之aidl进程间通讯数据传输

以你之姓@ 2022-08-31 15:29 212阅读 0赞

#### 一、前言 ####

AIDL是Android中IPC（Inter-Process Communication）方式中的一种，AIDL是Android Interface definition language的缩写，AIDL的作用是绑定一个其他APP的service，用于进程间的通讯。

在Android系统中，每个进程都运行在一块独立的内存中，在其中完成自己的各项活动，与其他进程都分隔开来。可是有时候我们又有应用间进行互动的需求，比较传递数据或者任务委托等，AIDL就是为了满足这种需求而诞生的。通过AIDL，可以在一个进程中获取另一个进程的数据和调用其暴露出来的方法，从而满足进程间通信的需求。

#### 二、使用 ####

##### 1、创建服务项目 #####

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3UwMTA1MjAxNDY_size_16_color_FFFFFF_t_70]  
**（1）定义aidl接口UserRemoteService和实体类User.aidl**

**UserRemoteService.aidl**

package com.example.server.user;
    
    import com.example.server.user.User;
    interface UserRemoteService { 
        User getUserByid(int id);
        int addUser(in  User user);//in 为客户端传输数据到服务端，out 为服务端传输数据到客户端
        void showToast(String msg);
    }

**User.aidl**

package com.example.server.user;
    parcelable User;

**（2）编写java代码**

**User.java**

public class User implements Parcelable, Serializable { 
    
        private int id;
        private String username;
        private String password;
    
        public User() { 
        }
    
        public User(int id, String username, String password) { 
            this.id = id;
            this.username = username;
            this.password = password;
        }
    
        public User(Parcel in) { 
            id = in.readInt();
            username = in.readString();
            password = in.readString();
        }
    
        public static final Creator<User> CREATOR = new Creator<User>() { 
            @Override
            public User createFromParcel(Parcel in) { 
                return new User(in);
            }
    
            @Override
            public User[] newArray(int size) { 
                return new User[size];
            }
        };
    
        public int getId() { 
            return id;
        }
    
        public void setId(int id) { 
            this.id = id;
        }
    
        public String getUsername() { 
            return username;
        }
    
        public void setUsername(String username) { 
            this.username = username;
        }
    
        public String getPassword() { 
            return password;
        }
    
        public void setPassword(String password) { 
            this.password = password;
        }
    
        @Override
        public int describeContents() { 
            return 0;
        }
    
        @Override
        public void writeToParcel(Parcel parcel, int flags) { 
            parcel.writeInt(id);
            parcel.writeString(username);
            parcel.writeString(password);
        }
    
        @Override
        public String toString() { 
            return "User{" +
                    "id=" + id +
                    ", username='" + username + '\'' +
                    ", password='" + password + '\'' +
                    '}';
        }
    }

注意：在构造函数中读取数据，读取的顺序要和写入的顺序一样，必须按照成员变量声明的顺序来，不然对象传输会丢失数据！已踩坑！  
**（3）编写服务service**

**UsersService.java**

public class UsersService extends Service { 
    
        @Override
        public void onCreate() { 
            super.onCreate();
        }
    
        @Override
        public int onStartCommand(Intent intent, int flags, int startId) { 
            return super.onStartCommand(intent, flags, startId);
        }
    
        @Nullable
        @Override
        public IBinder onBind(Intent intent) { 
            return new UserRemoteService.Stub(){ 
    
                @Override
                public User getUserByid(int id) throws RemoteException { 
                    User user = new User(id,"123456","lss0555");
                    return user;
                }
    
                @Override
                public int addUser(User user) throws RemoteException { 
                    Log.e("添加用户：",""+user.toString());
                    return 1;
                }
    
                @Override
                public void showToast(String msg) throws RemoteException { 
                    Handler handler=new Handler(Looper.getMainLooper());
                    handler.post(new Runnable(){ 
                        public void run(){ 
                            Toast.makeText(getApplicationContext(), "服务提示："+msg, Toast.LENGTH_LONG).show();
                        }
                    });
                }
            };
        }
    }

**（4）配置启动服务**

在 AndroidManifest.xml 声明服务

在界面种进行启动服务

Intent service = new Intent(getApplicationContext(),UsersService.class);
    startService(service);

##### 2、创建客户端项目 #####

![在这里插入图片描述][f51492298a1c4c3299cef35405366cd8.png]  
**定义aidl**  
将服务的User.aidl、User.java、UserRemoteService.aidl复制到项目下，文件的路径必须一致！

**测试类，连接远程服务，调用**

MainActivity.java

public class MainActivity extends AppCompatActivity { 
        private UserRemoteService userRemoteService;
        private ServiceConnection conn = new ServiceConnection() { 
            @Override
            public void onServiceDisconnected(ComponentName name) { 
                Toast.makeText(getApplicationContext(),"服务已断开",Toast.LENGTH_SHORT).show();
                userRemoteService = null;
            }
    
            @Override
            public void onServiceConnected(ComponentName name, IBinder service) { 
                Toast.makeText(getApplicationContext(),"服务连接成功",Toast.LENGTH_SHORT).show();
                userRemoteService = UserRemoteService.Stub.asInterface(service);
            }
        };
    
        @Override
        protected void onCreate(Bundle savedInstanceState) { 
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
    
            Intent intent = new Intent();
            intent.setPackage("com.example.server");
            intent.setAction("com.example.server.service.UsersService");
            bindService(intent, conn, Service.BIND_AUTO_CREATE);
        }
    
        //获取用户信息
        public void getUserInfo(View view) { 
            try { 
                User user = userRemoteService.getUserByid(888);
                Log.e("用户信息：",""+user.toString());
            } catch (RemoteException e) { 
                e.printStackTrace();
            }
        }
    
        //添加用户
        public void addUser(View view) { 
            try { 
                User user = new User(33, "lss0555", "123");
                int addUser = userRemoteService.addUser(user);
                Toast.makeText(getApplicationContext(),"结果："+addUser,Toast.LENGTH_SHORT).show();
            } catch (RemoteException e) { 
                e.printStackTrace();
            }
        }
    
        //提示功能
        public void maketip(View view) { 
            try { 
                userRemoteService.showToast("hello world");
            } catch (RemoteException e) { 
                e.printStackTrace();
            }
        }
    
        @Override
        protected void onDestroy() { 
            super.onDestroy();
            if(conn!=null){ 
                unbindService(conn);
            }
        }
    }

测试：

com.example.server E/添加用户：: User{ id=33, username='lss0555', password='123'}
    
    com.example.client E/用户信息：: User{ id=888, username='123456', password='lss0555'}

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3UwMTA1MjAxNDY_size_16_color_FFFFFF_t_70]: /images/20220829/63a6b887a5e44ed4b37acb70f1b9a194.png
[f51492298a1c4c3299cef35405366cd8.png]: /images/20220829/214a7c9da0804ea5bcef0906ba4d0272.png