如果服务在另一个进程中，该如何绑定? [英] How to bind Service if it's in another process?

问题描述

清单:

 <service android:name="com.example.MainService" android:process=":main_service"/>

尝试在活动"中绑定服务:

Trying to bind service in Activity:

public class MainActivity extends Activity {
    MainService mMainService;

    private boolean mBound;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        bindService(intentForMainService, mConnection, Context.BIND_AUTO_CREATE)
    }

    private ServiceConnection mConnection = new ServiceConnection() {
        public void onServiceConnected(ComponentName className,
                                       IBinder service) {
            MainService.MainServiceBinder binder = (MainService.MainServiceBinder) service;//HERE IS EXCEPTION
            mMainService = (MainService) binder.getService();
            mBound = true;
        }

        public void onServiceDisconnected(ComponentName className) {
            mMainService = null;
            mBound = false;
        }
    };

    @Override
    protected void onStop() {
        doUnbindService();
        super.onStop();
    }

    void doUnbindService() {
        if (mBound) {
          unbindService(mConnection);
        }
    }
}

错误:

    FATAL EXCEPTION: main
 Process: com.hos.android, PID: 9001
   java.lang.ClassCastException: android.os.BinderProxy cannot be cast to com.example.service.main.MainService$MainServiceBinder
   at com.example.ui.base.BaseServiceActivity$1.onServiceConnected(MainActivity.java:34)
   at android.app.LoadedApk$ServiceDispatcher.doConnected(LoadedApk.java:1335)
   at android.app.LoadedApk$ServiceDispatcher$RunConnection.run(LoadedApk.java:1352)
   at android.os.Handler.handleCallback(Handler.java:739)
   at android.os.Handler.dispatchMessage(Handler.java:95)
   at android.os.Looper.loop(Looper.java:158)
   at android.app.ActivityThread.main(ActivityThread.java:7224)

但是当我删除此 android:process =:main_service" 时，一切都正常

But when I delete this android:process=":main_service" all works properly

推荐答案

步骤1:编写一个AIDL文件，该文件描述了客户端可以绑定到的服务要导出的接口.出于此答案的目的，我将此接口称为Foo，因此AIDL文件将为Foo.aidl.请注意，如果客户端和服务位于单独的Android Studio模块中，并且两者都需要相同的Foo.aidl内容.

Step #1: Write an AIDL file that describes the interface to be exported by the service that clients can bind to. For the purposes of this answer, I will call this interface Foo, and so the AIDL file would be Foo.aidl. Note that if the client and service are in separate Android Studio modules that both need the same Foo.aidl content.

步骤2:让服务的资料夹扩展Foo.Stub并覆盖Foo.Stub上的方法，而不是扩展IBinder.

Step #2: Have your service's binder extend Foo.Stub and override the methods on Foo.Stub, instead of extending IBinder.

步骤3:在客户端的onServiceConnected()中，通过Foo.Stub.asInterface(service)将原始活页夹转换为Foo实例，并且Foo具有AIDL定义的API的客户端.

Step #3: In your client, in onServiceConnected(), convert the raw binder to a Foo instance via Foo.Stub.asInterface(service), and Foo has the client side of the AIDL-defined API.

这对示例项目对此进行了说明，其中我的情况是，客户端和服务位于单独的应用程序中.

This pair of sample projects illustrates this, where in my case the client and the service are in separate apps.

这篇关于如果服务在另一个进程中，该如何绑定?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！